What examination shows the ligaments of the eye. Eye examination

Diagnosis of glaucoma

NATIONAL GUIDELINES FOR GLAUCOMA
Edited by E.A. Egorova Yu.S. Astakhova A.G. Shuko
Authors and table of contents
Moscow. 2008

Early diagnosis aims to detect glaucoma before the development of atrophic processes in the nerve fibers of the ONH, the retina and in the GCS. An early diagnosis of glaucoma is possible when taking into account asymmetries in the condition of fellow eyes (glaucoma in most cases occurs and progresses asymmetrically), as well as risk factors.

It is practically impossible to determine the real beginning of the glaucomatous process. Even the diagnosis of suspicion of glaucoma, if it is further confirmed, means that the glaucoma process has already begun by this time, and it is not known when. Clinical manifestations while being minimal.

Risk factors for POAG.

1. Heredity. The prevalence of glaucoma among blood relatives of patients with POAG is 5-6 times higher than in the general population.

2. Age. POAG rarely occurs before the age of 40 years and the incidence increases in older age groups.

3. Myopia. Myopia is characterized by a decrease in the rigidity of the fibrous membranes of the eye and intraocular structures (trabecular and cribriform diaphragms) and an increased size of the scleral canal optic nerve.

4. Early development of presbyopia, weakening of the ciliary muscle.

5. Pronounced pigmentation of the trabecular apparatus.

6. Pseudoexfoliative syndrome.

7. Organic (atherosclerosis) and functional (vascular spasms) circulatory disorders in the vessels of the brain and in the ophthalmic artery.

8. Peripapillary chorioretinal dystrophy.

9. The occurrence of asymmetries in the parameters characteristic of the glaucoma process between paired eyes.

Anti-risk factors include:

• young age (up to 40-45 years old)
• hypermetropia
• good ciliary muscle function
• preservation of the pigment and stromal layers of the iris
• absence dystrophic changes in RBA structures
• pupillary response to light
• no symptoms of intraocular and cerebral circulation disorders.

The cardinal signs of glaucoma are an increase in IOP, atrophy of the optic nerve with excavation, and characteristic changes in the visual field.

In the initial stage of glaucoma, the last two signs may be absent or vague. Detection of increased IOP in the absence of characteristic changes in the optic nerve head (ONH) and in the state of the visual field does not allow the diagnosis of glaucoma. However, GON can also occur when normal level ophthalmotonus.

In this regard, early diagnosis of glaucoma is associated with significant difficulties, and often the correct diagnosis can be made only with dynamic observation by a qualified doctor, taking into account all the additional symptoms of the disease and risk factors. During the dynamic observation of the patient, a diagnosis of "suspicion of glaucoma" is made. The decision to prescribe antihypertensive treatment is decided individually.

Given the practical asymptomaticity of the initial stage of POAG, its early diagnosis is significantly difficult.

• biomicroscopy anterior section eyes,
• study of intraocular pressure and hydrodynamics of the eye,
• fundus,
• peripheral and central visual fields.

Biomicroscopic studies.

Conjunctiva

Biomicroscopy of the conjunctiva may require differential diagnosis congestive injection, characteristic of ciliary glaucoma, occurring with inflammation of the cornea and choroid. The localization and color of hyperemia should be assessed. Distinctive feature ciliary and mixed injection is the predominance of pericorneal localization and a bluish tinge of hyperemia. In doubtful cases with severe hyperemia, a single instillation of adrenaline can help to clarify the nature of the injection.

When examining the bulbar conjunctiva, pay attention to the condition of the conjunctival and episcleral vessels. A persistent increase in ophthalmotonus may be accompanied by a funnel-shaped expansion and tortuosity of the anterior ciliary arteries immediately in front of the site of scleral perforation (cobra symptom). A pronounced injection of the anterior ciliary arteries with the development of subsequent compensatory hyperemia of the entire vascular basin of the bulbar conjunctiva is characteristic of a sharp increase in ophthalmotonus (acute/subacute attack of glaucoma). Congestive injection also occurs when the blood circulation of the eye is disturbed as a result of compression of the vorticose veins and may be accompanied by chemosis. Edematous conjunctiva with severe hyperemia occurs in secondary glaucoma with a high level of ophthalmotonus.

Expansion of episcleral vessels can be with an increase in episcleral venous pressure in Sturge-Weber syndrome, in the presence of arteriovenous anastomoses, thyroid ophthalmopathy. A local chain of dilated episcleral vessels (sentinel vessels) may be a sign of a neoplasm in the eyeball.

At topical application prostaglandin analogues are also characterized by the development of hyperemia of the conjunctival vessels varying degrees, up to the appearance of petechial hemorrhages, with the abolition of the drug, hyperemia disappears. Long-term use of local antihypertensive drugs may be accompanied by a decrease in the production of lacrimal fluid, the development of hypersensitivity and allergy reactions, manifested by the phenomena of papillary and follicular conjunctivitis.

In the presence of filtration cushions, it is necessary to pay attention to their width, height, wall thickness, degree of vascularization and cystic changes.

Cornea

Epithelial edema in the form of microcysts indicates a significant, often acute, increase in ophthalmotonus.

Single or multiple horizontal ruptures of the Descemet's membrane (Haab bands) accompany an increase in the diameter of the cornea in congenital glaucoma. The same, but vertical defects indicate a birth trauma).

Pathological changes in the corneal endothelium, listed below, can serve as signs of various, incl. secondary, forms of glaucoma.

• Krukenberg's spindle (accumulation of pigment from the iris in the form of a vertical column on the endothelium of the cornea) in pigmentary glaucoma;
• deposits of pseudoexfoliations (protein complexes) in pseudoexfoliative syndrome in primary glaucoma, in addition to the endothelium, cover the capsule and ligaments of the lens, the pupillary edge of the iris and the angle of the anterior chamber of the eye;
• endothelial precipitates in uveal glaucoma;
• small-focal opacities of the deep layers of the central cornea (guttatae) in Fuchs endothelial dystrophy. It is typical for the initial stages, then corneal edema develops up to bullous keratopathy;
• chaotic small defects of the endothelium, surrounded by indistinct halos or several vacuole-like changes with dense opacities around a strip of altered endothelial cells in the Descemet's membrane in posterior polymorphic corneal dystrophy. These cells, which take on the features of epithelial cells, can cover the trabecular meshwork, which in 10-15% leads to the development of glaucoma;
• gray color of the posterior collagen layer in iridocorneal endothelial syndrome. The syndrome includes essential atrophy of the iris (progressive atrophy, defects in the iris, changes in the shape of the pupil and peripheral anterior synechia), Chandler's syndrome (changes in the posterior collagen layer of the cornea with diffuse edema), Cogan-Reese syndrome (iris atrophy, endotheliopathy and corneal edema, nevus of the iris ).

It should be noted corneal dysgenesis in Axenfeld-Rieger syndrome, which in a non-syndromic form is also manifested by iris hypoplasia with pupil displacement, anterior displacement of the Schwalbe line.

Also pay attention to the presence of cicatricial lesions of the cornea of ​​a surgical or traumatic nature.

Front camera

In glaucoma, the depth of the anterior chamber is assessed. Normally, in the pupil area, it is 2.75-3.5 mm. Depending on the depth, a deep chamber is distinguished (with pseudophakia, high myopia), medium depth, shallow or slit-like with angle-closure glaucoma, the anterior chamber may also be absent.

Pay attention to the uniformity of its depth. A deep chamber in the center and shallow on the periphery may be a sign of pupillary block due to posterior synechia. It is also necessary to conduct a comparative assessment of the depth of the chamber in both eyes.

An indirect assessment of the width of the angle of the anterior chamber is carried out according to the Van Herick method: behind a slit lamp, a narrow light slit illuminates the periphery of the cornea at an angle of 60° as close as possible to the limbus. As a rule, the study begins with illumination of the opaque area of ​​the limbus, smoothly moving the light gap to the cornea until a strip of light appears on the periphery of the iris. The light band of the optical section of the cornea, the band of light on the surface of the iris, and the distance from the inner surface of the cornea to the iris are visualized.

Scheme for estimating the width of the angle of the anterior chamber according to the Van Herick method.

The width of the angle of the anterior chamber is judged by the ratio of the thickness of the optical section of the cornea (SR) to the distance of the cornea-iris (RR).

This test allows an indirect assessment of the CAA and cannot serve as an alternative to gonioscopy.

For the differential diagnosis of primary and secondary glaucoma, it is necessary to assess the transparency of intracameral moisture, the presence of inflammatory cells, erythrocytes, fibrin, and the vitreous body. All signs of an inflammatory reaction must be recorded before the appointment of local (antihypertensive) therapy.

iris

Inspection of the iris should be carried out before pupil dilation. Heterochromia, atrophy of the stroma and pupillary border of the iris, transillumination defects, pigmented neoplasms, and pseudoexfoliation deposits are noted.

With secondary neovascular glaucoma or in the terminal stages, it is possible to detect a network of small newly formed vessels on the surface of the iris or along the edge of the pupil.

Attention should be paid to signs of trauma, such as sphincter defects, iridodenesis, the presence of basal coloboma, traces of laser iridectomy.

The level of pigmentation of the iris is noted before the appointment of local antihypertensive therapy (analogues of prostaglandin F2a).

When examining the pupil, it should be noted that its size may change under the influence of local therapy. So, drug-induced miosis indicates the use of miotics.

The degree of destruction of the pupillary pigment border can serve as an indirect assessment of the duration and degree of increase in ophthalmotonus. Deposits of pseudoexfoliation indicate the presence of pseudoexfoliation syndrome. A change in the shape and location of the pupil can be observed with various forms secondary glaucoma, with angle-closure glaucoma as a result of sectoral atrophy of the iris.

lens

Biomicroscopy of the lens is most informative in the state of mydriasis. Along with transparency, size and shape, deposits of pseudoexfoliation, phacodonesis, subluxation and dislocation of the lens are noted.

With phacomorphic glaucoma, a unilateral swelling cataract is more often detected. Biomicroscopy of the lens in this case shows uneven clouding, water gaps and a tense lens capsule, as well as a shallow anterior chamber, bombardment of the periphery of the iris, a narrow or closed angle.

White deposits in the form of small spots on the anterior lens capsule are often found in phacolytic glaucoma, caused by the appearance of small defects in the lens capsule, through which large protein molecules and macrophages with lens substance enter the eye chambers, clogging the trabecular fissures and pores.

Dislocation of the lens into the anterior chamber, into the vitreous body and subluxation of the lens can be complicated by phacotopic glaucoma.

There are subluxation and dislocation (dislocation) of the lens. With subluxation, weakening or partial rupture of the zinn ligaments occurs. The lens trembles as the eye moves, but maintains its correct position in the posterior chamber. The dislocation is characterized by a violation of the integrity of the zinn ligaments (complete or over a considerable extent) and the displacement of the lens. At the same time, it may end up in the anterior chamber, the vitreous body, or, remaining in the posterior chamber, move in the direction where the zinn ligaments are preserved.

In the presence of an intraocular lens, its type and position, as well as the condition of the posterior capsule, are noted.

Gonioscopy.

Currently, gonioscopy is one of the basic diagnostic methods research in glaucoma. Inspection of the angle of the anterior chamber should be carried out when making a diagnosis, when deciding on further treatment tactics (therapeutic, laser, surgical), as well as in the postoperative period.

As mentioned above, without gonioscopy, only an indirect assessment of the width of the iridocorneal angle is possible. It is known that the light reflected by the structures of the angle of the anterior chamber falls on the interface between the two media "tear film - air" at an angle of 46°, completely reflected from it into the stroma of the cornea. This optical effect prevents direct visualization of the anterior chamber angle (ACA). A gonioscope made of glass or plastic, placed on the surface of the cornea, eliminates the reflection effect, and the slit-like space between the gonioscope and the corneal epithelium is filled with the patient's tear, saline, or transparent gel.

gonioscopy technique. After sterilization of the gonioscope and instillation anesthesia, the patient's head is tightly fixed behind a slit lamp. It is desirable to install the gonioscope after orienting the slit lamp to the patient's eye to facilitate the centering of the device. The patient is asked to look straight ahead. The illuminator is moved to the side. When using gonioscopes with a haptic part, it is first introduced behind the eyelids. A gonioscope with a haptics should be inserted before the head is fixed behind the slit lamp, after the lamp has been previously adjusted to the eye being examined.

The contact surface of the gonioscope is brought into contact with the cornea of ​​the examined eye. In this position, the gonioscope is held with the fingers of one hand (usually the left) throughout the study. The second hand controls the slit lamp.

Single-mirror gonioscopes of conventional types make it possible to see at any given moment only the opposite section of the iridocoronal angle. To inspect the CPC throughout its entire length, it is necessary to rotate the gonioscope around its longitudinal axis.

As a rule, during the screening examination, it is sufficient to examine only the lower and upper portions of the angle of the anterior chamber.

Identification zones of the corner. The APC zones are considered in a narrow optical "cut", since under diffuse illumination in a wide beam of light, the details of the APC are smoothed out.

The identification zones of the angle include: the anterior border ring of Schwalbe, notch, trabecula, Schlemm's canal (SC), scleral spur, ciliary body and iris root.

Rice. Diagram of the angle of the anterior chamber.

1. front border - Schwalbe ring;
2. tenderloin;
3. trabecula;
4. Schlemm's canal;
5. scleral spur;
6. ciliary body tape;
7. periphery of the iris root

Van Beuningen (1965) describes the identification zones of the PC angle in this way.

1. Front boundary ring Schwalbe. The different slopes of the Schwalbe boundary ring are recognized by the direction of the narrow beam of light. Part of the anterior boundary ring of Schwalbe has the form of a gentle elevation of the cornea with a slope gradually descending towards the center of the cornea, and with a steeper slope going towards the APC. The border ring is expressed to varying degrees and is not as transparent as the cornea.

2. Notch - a more or less pronounced depression at the transition point of the posterior slope of the anterior boundary Schwalbe ring to the corneoscleral trabecula. Here, especially in the lower parts of the CPC, there is an accumulation of pigment. Its amount varies depending on the age and nature of the pathological process in the eye.

3. Corneoscleral trabecula - a translucent triangular prismatic strip of changing color, mostly pale gray, yellowish to white. The degree of turbidity of the trabeculae may vary depending on the age or disease of the eye.

4. Schlemm's canal in most cases appears as a gray shadow lying approximately in the middle of the trabecula, and is more prominent with a narrow gap. When blood seeps into the SC, it glows red. This phenomenon is possible with an increase in pressure in the episcleral veins above the level of ophthalmotonus, more often with compression of the episcleral veins by the haptic part of the gonioscope. It is also observed with hypotension of the eye and with a pathological increase in pressure in the episcleral veins (carotid-cavernous anastomosis, Sturge-Weber syndrome).

5. Scleral spur - a rather sharp white line delimiting the trabecula from the strip of the ciliary body. Scleral spur or posterior border Schwalbe ring of unequal width and not always equally light. Its color depends on the density of the tissue covering the spur.

6. The strip of the ciliary body is gray-brown in color, slightly shiny. Sometimes it determines the wrong circular striation. With age, as well as with glaucoma, it becomes dull gray, loose and narrower. In addition, pathological deposits in the form of pigment and exfoliation can also be observed on it.

7. At the root of the iris, two or three circularly located folds are formed. The last fold ("Fuchs' furrow") is the peripheral part of the iris root. Usually circular folds are more or less pronounced. But sometimes, as a variant of the physiological norm, they may be absent. Under normal conditions, the periphery of the iris root occupies a different position in relation to the corneoscleral wall: it can be located directly opposite the spur, and opposite the SC, and opposite the anterior border ring of Schwalbe. These different positions of the periphery of the iris root do not always indicate the presence of pathological changes Code of Criminal Procedure.

In some individuals, thin fibers of the pectinate ligament can be seen running across the strips of the ciliary body. It consists of iris fibers that extend from its root to the trabecula, approximately in the region of the scleral spur, and reach the region of the SC.

If the pectinate ligament is not a pathological sign, then the formation of goniosynechia or anterior synechia in the area of ​​​​the ACL is observed in primary and secondary glaucoma and may be associated with inflammatory processes. It is possible to observe soldering of the root of the iris with the band of the ciliary body, scleral spur, trabecula, Schwalbe's ring and cornea. Depending on this, goniosynechia are divided into ciliary, trabecular and corneal. Compared to the pectineal ligament, the goneosynechia are usually more dense and wide in appearance, and may partially cover the iridocorneal angle.

important diagnostic sign is the pigmentation of the Schlemm's canal and trabeculae, which develops as a result of the settling of pigment granules that enter the aqueous humor during the breakdown of the pigment epithelium of the iris and ciliary body. The intensity of pigmentation increases with age and is more pronounced in individuals with densely pigmented irises. Often the pigment deposition is segmental in nature with predominant localization in the lower sector.

With the accumulation of pigment in the SC itself, they speak of the endogenous or internal nature of pigmentation. In this case, the pigment is visualized as a uniform light brown strip located inside the channel. When pigment is deposited on the trabecula itself from the side of the anterior chamber (exogenous or external pigmentation), a slightly protruding dark brown or black pigment chain or rug is noted. When both types of pigmentation are combined, they speak of its mixed character.

A.P. Nesterov proposes to evaluate the degree of pigmentation of the trabeculae in points from 0 to 4.

• The absence of pigment in the trabeculae is indicated by the number "0"; weak pigmentation of its rear part - 1 point;
• intense pigmentation of the same part - 2;
• intense pigmentation of the entire trabecular zone - 3 points;
• intense pigmentation of all structures of the anterior wall of the APC - 4 points.

In healthy eyes, pigmentation often appears in middle and old age, and its severity according to the given scale is estimated at 1-2 points.

Normally, blood vessels can occasionally be found in the APC. These are branches of the anterior ciliary arteries or arterial circle of the ciliary body, oriented either radially along the iris, or running serpentine along the ciliary body. Newly formed thin vessels running along the surface of the iris, through the scleral spur to the trabeculae, are pathological. Newly formed vessels in Fuchs' heterochromic cyclitis are thin, branched and tortuous. Vessels in neovascular glaucoma are characterized by a direct course along the surface of the ciliary body through the scleral spur to the trabecula with multiple branching in the latter zone. It is believed that contraction of myofibroblasts in these vessels may lead to the development of synechiae.

Forms of the angle of the anterior chamber. The width of the APC is determined by the distance between the iris root and the anterior boundary ring of Schwalbe (the entrance to the angle bay), as well as the relative position of the iris root and the corneoscleral wall.

When determining the shape of the APC, it is necessary to use a narrow slit, trying to obtain an optical section of the tissues that form the angle. In this case, one can observe how the incident light beam bifurcates in the region of the notch with the formation of the so-called "fork". The shape of the angle is determined by the degree of closure of the identification zones of the angle by the iris and by the degree of separation of the root of the iris from the fork. It is advisable to use the last sign in cases where the identification zones are indistinctly expressed, obscured. It should be noted that a correct assessment of the width of the ACA during gonioscopy is possible only if the patient is looking straight ahead and the gonioscope is located in the center of the cornea. By changing the position of the eye or the inclination of the gonioscope, all identification zones can be seen even at a narrow angle.

There are several systems that determine the degree of width of the CPC. In domestic ophthalmology, the Van Beuningen scheme (1965) has become widespread:

1. Wide or open angle, in the form of a groove or a blunt beak - all of the above identification zones are visible. The band of the ciliary body usually appears wide. A wide APC is more common in myopia and aphakia.

2. An angle of medium width in the form of a blunt or sharp beak - the above formations are visible without the anterior part of the ciliary body, the strip of which is almost completely covered by the root of the iris. Most of the trabecular zone is open. An angle of medium width is much more common than other forms.

3. Narrow angle. In the presence of a narrow angle, identification zones can be seen only up to the scleral spur. The band of the ciliary body and the scleral spur are covered by the root of the iris. Sometimes the area of ​​the corneoscleral trabecula is also partially covered. A narrow angle is most commonly seen in patients with hyperopic refraction.

4. Closed corner. The closed angle is characterized by the fact that the iris covers all its zones and is adjacent to the anterior boundary ring of Schwalbe. In this case, the root of the iris touches the place where the beam of light bifurcates - the “fork”; the latter, as it were, rests against the tissue of the iris. The closed form of the angle is pathological and occurs during an acute attack of glaucoma, in the case of blockade of the angle zones by a tumor of the iris, etc.

Often, when examining a narrow or closed CPC, it is necessary to decide whether its blockade is functional or organic. A gonioscopic test with corneocompression (Forbes test) allows you to decide to what extent the iris root is fixed to the filtering zone and to what extent it can be repositioned.

The Forbes test can be performed as part of a conventional gonioscopy using a gonioscope without a haptic part. Observing the angle of the anterior chamber (usually its upper sector), the gonioscope is pressed quite strongly on the cornea. The emerging folds of the posterior boundary plate are somewhat smoothed out under even stronger pressure, and observation of the angle of the anterior chamber becomes possible. The fluid of the anterior chamber is pushed to the periphery and pushes the basal part of the iris back. If the synechia is not pronounced, then when the root of the iris moves back, a large part of the filtering zone opens; if the synechiae are extensive, then the root excursion is insignificant or absent.

Ultrasonic biomicroscopy.

Ultrasonic biomicroscopy (proposed by Charles Pavlin in 1990) - scanning ultrasonic immersion diagnostic procedure with linear scanning, which provides quantitative and qualitative information about the structure of the anterior segment of the eye.

Allows you to visualize in detail the anterior and posterior chambers of the eye without violating the integrity of the eyeball, to conduct a qualitative and quantitative assessment of its structures, to clarify the spatial relationships of the cornea, ciliary body, iris, lens in opaque refractive media, to assess the state of surgically formed outflow tracts.

The study was carried out in an immersion medium under local instillation anesthesia with a solution of 1% dicaine with the patient lying on his back.

Study of intraocular pressure and eye hydrodynamics

Critical importance in establishing the diagnosis of glaucoma has a state of ophthalmotonus. Normal IOP is a statistical concept.

For an integral assessment of ophthalmotonus, it is necessary to distinguish between:

• The statistical norm of IOP,
• his individual level
• the concept of tolerant IOP,
• target pressure

The statistical norm of true IOP is from 10 to 21 mm Hg.

Tolerant IOP is a term introduced by A.M. Vodovozov in 1975. It already refers directly to the glaucomatous process and indicates the level of ophthalmotonus, which does not have a damaging effect on the internal structures of the eyeball. Tolerant IOP is determined using special unloading functional tests.

And, finally, the term “target pressure level” has been introduced into practice only recently. "Target pressure" is determined empirically, taking into account all the risk factors that this particular patient has, and, just like tolerant pressure, should not affect eyeball damaging action. The definition of "target pressure" is the result of a detailed examination of each individual patient.

Currently, for the purposes of early diagnosis, we recommend focusing on daily tonometry. Maklakov's tonometer, Goldman's applanation tonometer or different types non-contact tonometers.

For screening purposes or for home use, the patients themselves may be recommended a transpalpebral tonometer of the PRA-1 type (Ryazan Instrument-Making Plant).

When analyzing tonometry data, the absolute figures of IOP, daily fluctuations and the difference in ophthalmotonus between the eyes are taken into account. Daily fluctuations in IOP, as well as its asymmetry between the two eyes in healthy individuals, as a rule, is within 2-3 mm Hg. and only in rare cases reaches 4-6 mm Hg.

If glaucoma is suspected, daily tonometry is performed without the use of antiglaucomatous antihypertensive drugs. The total number of measurements, as a rule, is at least 3 in the morning and 3 in the evening. They can be carried out discretely, with a break during the week or 10 days.

When checking the effectiveness of the drug regimen in patients with an established diagnosis of glaucoma, daily tonometry is performed under the following conditions: IOP is measured in the morning and evening before the instillation of antihypertensive drugs to determine the level of pressure at the end of the drops.

Currently, we recommend focusing on daily tonometry. When analyzing daily reusable tonometry, the absolute figures of IOP, daily fluctuations and the difference in IOP between the eyes are taken into account. Daily fluctuations in IOP, as well as asymmetry of ophthalmotonus between the eyes in healthy individuals, as a rule, are within 2-3 mm Hg. Art. and only in rare cases reach 4 mm Hg. Art.

If glaucoma is suspected, daily tonometry is performed without the use of antiglaucomatous antihypertensive drugs. The number of measurements, as a rule, is at least 3 in the morning and 3 in the evening. They can be carried out discretely, with a break during the week or 10 days.

For tonographic studies highest value have data on true IOP (norm up to 21 mm Hg) and the coefficient of ease of outflow (the norm for patients over 50 years of age is more than 0.13).

Water-drinking or positional samples are used to indirectly assess the ease of outflow of AH. The patient is asked to drink a certain amount of liquid (usually 0.5 liters) in a short period of time (usually 5 minutes), then laid on his stomach with eyes closed for 30-40 minutes and measure IOP during the first hour. If IOP rises by 5 or more units, the test is considered positive.

Effect of anesthesia on IOP measurement

Measurement of IOP by applanation tonometry requires local anesthesia, which does not affect pressure. However, in children it is usually used general anesthesia. Generally, halothane lowers IOP, while ketamine can lead to a transient increase in IOP. With ketamine, IOP is typically 4 mmHg higher than with halothane. Oxygen used during anesthesia has a hypotensive effect, and carbon dioxide has a hypertensive effect. Succinylcholine and nitric oxide can cause transient hypertension up to 15 mm Hg.

Norm of IOP in children

IOP increases by approximately 1 mm Hg. for 2 years from birth to 12 years of age, increasing from 12-14 mm Hg at birth to 18 ± 3 mm Hg. by the age of 12.

Factors affecting the level of IOP

One of the factors affecting the level of measured IOP is the degree of corneal rigidity. Thin cornea (less than 510 µm), post-PRK and LASIK conditions can result in an erroneously low IOP measurement. Thick cornea (more than 560-580 microns), a condition after keratitis, after keratotomy, can lead to an erroneously high level of IOP.

In addition, a tight collar or tight tie, Valsalva, holding the breath, using an eyelid speculum, or pressing on the eyelids can lead to falsely high IOP measurements.

Fundus examination

The most optimal method for determining changes in the structure of the optic nerve head is stereoscopy:

• indirect ophthalmoscopy on a slit lamp with lenses 60D or 90D;
• direct ophthalmoscopy on a slit lamp through the central part of the Goldmann lens or Van-Boiningen lens.

Before the examination, in order to increase the effectiveness of the examination, it is necessary to dilate the pupils with short-acting mydriatics. A contraindication to mydriasis is an acute attack of glaucoma or a previous attack on the fellow eye.

Usually physiological excavation of the optic nerve head has a horizontal-oval shape. Increased physiological excavation with a large disc size often has a rounded shape. Normal excavation in both eyes is symmetrical. At the same time, in 96% of cases, the E/D ratio is within 0.2DD.

Glaucoma is characterized by atrophic changes in the ONH. Clinically, they manifest themselves in decoloration (blanching) of atrophic areas of the disc, in the expansion and deformation of its excavation. In the initial stage of glaucoma, there are no clear differences between physiological and glaucomatous excavation. Gradually there is a decrease in the width of the neuroretinal ring. Thinning can be uniform around the entire circumference, local marginal or combined. Usually, the shape and relative size of the excavation, its depth, and the nature of the temporal margin are taken into account.

When examining the ONH, the following signs are recorded: the relative value of the excavation (the ratio of the maximum size of the excavation to the diameter of the disk - E / D), the depth of the excavation (shallow, medium, deep), the nature of the temporal edge (sloping, steep, undermined), the color of the neuroglia (pink, decolorized, narrowing of the neuroretinal rim, tendency to vertical excavation), the presence of a - zone (peripapillary scleral rim). Extension of excavation d.z.s. usually occurs in all directions, however, more often the expansion of the excavation occurs in the vertical direction due to the thinning of the neuroretinal ring in the upper and lower sectors, which is associated with the structural features of the cribriform plate.

A single study of the ONH does not allow us to draw final conclusions about the presence or absence of glaucomatous changes due to the large variability of its structure and age-related changes. However, it should be noted that the excavation size from 0 to 0.3 should be attributed to normal sizes, from 0.4 to 0.6 should be attributed to the group of relative increase within age-related changes for people over 50 years old, and more than 0.6 - to the group of increased risk of developing glaucomatous atrophy.

When examining a patient with elevated IOP, the principle should be followed: the larger the excavation, the more likely it is glaucomatous.

Of certain importance is the blanching of the disc surface, the ophthalmoscopically visible displacement of the vascular bundle, the presence of peripapillary atrophy of the choroid.

It is recommended to pay attention to the terrain and the course pattern nerve fibers on the retina, which in glaucoma looks blurred and intermittent. These details are best seen when using a redless or blue filter.

In patients with glaucoma, atrophy of the choroid in the peripapillary region, atrophic changes in the retina in the layer of nerve fibers, and small, linear hemorrhages may occur, often located along the periphery or along the edge of the disc.

Thus, during discoscopy, a qualitative assessment is carried out

• the contour of the neuroretinal ring, its absence (marginal excavation) or the tendency to its breakthrough to the edge
• · hemorrhages on the surface of d.z.n.
• Peripapillary atrophy
• shift of the vascular bundle

Quantification

• excavation to disc ratio (E/D)
• The ratio of the neuroretinal ring to the disk

To document the state of d.z.s. it is convenient to use color photographs; in the absence of a fundus camera, schematic drawings can be used.

In addition to clinical methods of examination of doctors of sciences, methods are increasingly being used today that allow a qualitative assessment of the state of nervous structures. These are confocal scanning laser ophthalmoscopy (Heidelberg retinal tomography - HRT), scanning laser polarimetry (GD) and optical coherence tomography (OST). It must be emphasized that the data obtained using these devices should not be interpreted as a final diagnosis. The diagnosis should be made taking into account the totality of all clinical data, such as disc condition, visual field, IOP, age, and family history. But at the same time, the confirmed deterioration in the state of d.z.n. is an important predictor of glaucoma progression.

METHODS OF VISUALIZATION OF THE RETINA AND THE HEAD OF THE OPTIC NERVE.

AT last years in the diagnosis of glaucoma, methods of structural and topographic analysis (visualization) of the retina and optic nerve head (ONH) are increasingly being used. Under the visualization (imaging - imaging) understand the acquisition and registration of intravital images in digital format. Research is carried out with various devices using and various methods measurements. In practice, the most commonly used

1. Optical coherence tomography - OCT (Stratus OCT 3000 from Carl Zeiss Meditec);

2. scanning laser polarimetry - SLP (device GDx VCC by Carl Zeiss Meditec);

3. confocal scanning laser ophthalmoscopy - XLO (Heidelberg Retina Tomograph device - HRT 2, HRT 3 from Heidelberg Engineering);

4. laser biomicroophthalmoscopy (Retinal Thickness Analyzer - RTA by Talia Technology).

In glaucoma, all of the considered methods are used to assess the state of the retinal nerve fiber layer (RNFL) and, except for DLS, to study ONH. As shown in the previous section, certain data on the state of ONH, including quantitative data, can be obtained using ophthalmoscopy and fundus photography. With regard to SNFL, the methods under consideration open up fundamentally new possibilities. Experienced investigators are able to detect nested RNFL defects with direct ophthalmoscopy or biomicroophthalmoscopy. Ophthalmoscopy and photography in redless light are more informative. However, only the considered methods make it possible to assess in detail the changes in RNFL and give them a comprehensive quantitative assessment.

Conducting research does not require special preparation of patients. An important role is played by the transparency of the optical media of the eye. Even slight turbidity can distort quantitative measurement results. The Stratus OCT 3000 device is less sensitive to such opacities. Pupil width also has a certain value. With a very narrow pupil (less than 2 mm), examination can be difficult, especially on the Stratus OCT 3000. However, in most cases, with natural pupil width, examination is feasible on all devices.

Visualization (study of morphometric criteria) of the optic nerve head.

The role of ONH studies in diagnosing glaucoma and assessing its progression is beyond doubt and is discussed in detail in the previous section. The significance of ONH visualization methods lies in the fact that they provide the most accurate quantitative assessment and statistical analysis of ONH parameters, which makes it possible to transfer this section of glaucoma diagnostics to a qualitatively higher level.

It should be noted that when glaucoma occurs, changes in ONH usually appear somewhat later than changes in RNFL and are less specific. Therefore, in terms of early diagnosis of glaucoma, ONH imaging is less informative than RNFL studies. With regard to the assessment of the progression of the disease, the dynamics of changes in ONH has an equally important role.

The HRT 2 device registers a detailed "topographic" map of the surface of the OHP. Precise measurements are made of the main parameters of the GZN: its area; area, depth and volume of excavation, area and volume of the neuro-retinal rim (NRP), E/D ratio, etc. To assess the excavation, a special indicator of its shape (cup shape measure) is also used. The resulting values ​​are compared with the ranges normal values. In addition, an in-depth statistical (Moorfields regression classification) analysis of the ONH parameters in its 6 sectors is carried out, each of which is assessed as normal, borderline, or beyond the normal range. Cup shape index and Moorfield analysis results are considered to be the most informative in diagnosing glaucoma on HRT 2.

There are also analysis programs that allow one to evaluate the dynamics of the ONH parameters during repeated measurements.

Almost the same indicators, except for the Moorfield analysis, are also calculated on the RTA instrument. The difference of each indicator from the norm is evaluated statistically as not significant or significant with one or another probability (<5%, <1% и т.д.). Относительно меньшее распространение прибора в клинике ограничивает информацию о его достоинствах и недостатках.

The Stratus OCT 3000 optical coherence tomograph for the analysis of ONH makes 6 transverse sections in different meridians. The software of the device determines the edges of the cribriform plate and calculates all the necessary parameters - the area of ​​the ONH, the area and volume of the excavation and the neuro-retinal rim, the E/D ratios are linear and by area (Fig. 2). However, there is no statistical evaluation of these parameters (comparison with the normative database), which somewhat reduces the significance of the measurements performed. There is also an element of interpolation, since the ONH is measured only in those areas where optical sections pass, which characterize the state of the ONH only partially, especially along its edges. On the other hand, an important advantage of the device is the use of reliable identification points during measurements (the edges of the lattice plate), while in the other two devices the disk contours are determined manually by the operator, which contains a large element of subjectivity and is a potential source of errors.

In view of the above, all the considered devices provide an adequate assessment of ONH in patients with glaucoma. The Stratus OCT 3000 optical coherence tomograph, unlike the HRT2 and RTA, does not perform a statistical comparison with a normative database, but provides a more objective definition of ONH boundaries.

Visualization of the retinal nerve fiber layer (RNFL).

Quantitative assessment of RNFL in the peripapillary region is one of the most informative methods for early diagnosis of glaucoma and assessment of its progression dynamics. Many authors note that RNFL disorders, as a rule, not only precede changes in ONH, but often develop earlier than perimetric changes and may be the main clinical sign of the so-called "preperimetric" glaucoma.

The RNFL is unevenly distributed around the ONH, having the greatest thickness at its upper and lower poles. The curve of dependence of RNFL thickness on the position around the ONH on a circular peripapillary section has a two-hump shape with maxima in the upper and lower, and minima in the temporal and nasal quadrants.

RNFL studies on the Stratus OCT 3000 can be carried out using several scanning programs (protocols). The protocol "RNFL thickness (3.4 mm)" is adopted as standard. According to this protocol, RNFL measurements are taken on a 3.4 mm diameter circle manually centered on the ONH. The OCT method directly measures the thickness of the RNFL, which is optically denser than the adjacent retinal layers. The results are graphically expressed as a RNFL thickness curve. Quantitatively, the device calculates the average thickness of the RNFL in 12 sectors, 4 quadrants and the total average (over the entire perimeter). Additional calculated indicators and their differences (difference) for the right and left eyes are calculated. Results and relative estimates are compared statistically against an extensive regulatory framework that takes into account patient age and gender. The RNFL thickness curve is evaluated by its position on the graph relative to the normal, borderline, and pathological zones, highlighted in green, yellow, and red, respectively. The obtained quantitative values ​​of the indicators are marked with the same colors, which makes it easier to evaluate the results (Fig. 3)

The GDx VCC is a specialized instrument designed exclusively for the study of RNFL. This layer has polarizing properties, and the degree of polarization, determined by laser polarimetry, is proportional to its thickness. The device takes measurements at each point of a rectangular area measuring 15° x 15° around the ONH. Similar to the Stratus OCT, a RNFL thickness curve is plotted, a series of summary measures of RNFL thickness (overall mean - TSNIT, and its standard deviation, upper and lower quadrant means) are determined, and all measurements and scores are statistically compared against a broad regulatory framework for age and gender of the patient. Only on this device, the asymmetry of the data in both eyes is statistically evaluated. A very informative "indicator" of the state of RNFL (Nerve Fiber Indicator - NFI) is also calculated, which gives an integral assessment of the deviations of all measured parameters from normal values. In addition, the printout of the results (Fig. 4) provides maps of the thickness of the RNFL in the entire study area and maps of deviations from the norm (Deviation Map), where the difference in the thickness of the RNFL from the normative base at each point is estimated statistically and the degree of deviation is highlighted by the corresponding color (red - in the case of the most pronounced changes).

Both considered devices have analysis programs that allow one to evaluate the dynamics of RNFL parameters during repeated measurements.

Unlike those described, the other two instruments (HRT2 and RTA) do not have the ability to accurately measure RNFL. This is due to their insufficient depth resolution (300 and 52 µm, respectively, compared to, for example, 8–10 µm for OCT).

As noted above, the XLO method used in the HRT 2 device allows obtaining a detailed map of the topography (surface relief) of the ONH and the surrounding retina. But the thickness of the RNFL is not measured directly, but indirectly, as the protrusion of the edge of the ONH in relation to the relative (reference) plane of the retina (figuratively, this can be compared with an assessment of the total size of an iceberg by measuring only its surface part). The RNFL thickness curve is qualitatively assessed by its shape and distance above the reference plane (Fig. 5). Only one indicator is quantitatively evaluated - the average thickness of RNFL in comparison with the normative range, which does not take into account the age and sex of the subjects.

The same principles apply to the evaluation of RNFL with the RTA instrument. In addition to the average thickness of the RNFL, the RTA also quantifies the cross-sectional area of ​​the RNFL.

Thus, adequate methods for the study of RNFL in patients with glaucoma and suspected glaucoma are scanning laser polarimetry on the GDx VCC and optical coherence tomography using the Stratus OCT 3000. As shown in a number of works, the assessment of RNFL using the HRT 2 and RTA devices is not sufficiently informative and can only be used as an auxiliary method. Only one of the considered methods and instruments, OCT on the Stratus OCT 3000, simultaneously provides a qualitative characterization of both RNFL and ONH.

Visual field examination

The field of view is the area of ​​space perceived by the eye with a fixed gaze. Perimetry is a method of studying the visual field using moving (kinetic perimetry) or stationary stimuli (static perimetry).

The space visible to the eye has boundaries. However, within these boundaries, the possibilities of visual perception are very uneven. In the center (in the region of the fixation point), the eye is able to distinguish the most insignificant differences in illumination, while at the periphery of the field of view, the ability to distinguish is several orders of magnitude lower. Light sensitivity serves as a quantitative characteristic of this ability. Measurement of light sensitivity in different parts of the field of view allows you to get its 3-dimensional model in the form of the so-called "island of the field of view" (Fig. 1). The horizontal section of the "island" shows the distance of various parts of the field of view from the visual axis in degrees, and the position relative to the vertical axis characterizes the light sensitivity of any point in decibels (dB). Normally, maximum photosensitivity (the top of the "island") is observed at the point of fixation. Light sensitivity gradually decreases towards the periphery of the field of view. The blind spot looks like a deep "mine" in the temporal part of the visual field.

Unlike campimetry (see below), perimetry, both kinetic and static, is performed using hemispherical or arc perimeters, so distances from the visual axis are measured in degrees, and the radius of the sphere (arc) does not matter (usually it is 30 or 33 cm).

The results of perimetry are presented in the form of 2-dimensional (planar) maps (schemes) of a 3-dimensional "island" of the field of view. Depending on the type of perimetry, these maps look different. With kinetic perimetry, only the boundaries of the field of view (in degrees along the arc) are noted. Depending on the properties of the stimulus (test object), the boundaries may be somewhat wider or narrower (Fig. 1B). Therefore, in international practice, standard stimuli are used that have certain sizes and brightness. With static perimetry, the specific photosensitivity of certain areas of the field of view is determined and shown on the diagrams in the form of specific numbers or using a conditional black and white scale (Fig. 1B).

Historically, numerous varieties of perimetry have been developed and used. To date, the requirements of clinical practice in relation to glaucoma have significantly limited the number of such techniques. The main ones will be described below.

Kinetic perimetry. Its main purpose is to study the peripheral boundaries of the field of view, to some extent it is also possible to identify large areas of complete or partial loss of photosensitivity (absolute and relative cattle), in particular, to determine the boundaries of the blind spot. The study is carried out sequentially in several, more often in 8 meridians, by smoothly moving the test object along the perimeter surface from the periphery to the center until the subject notices it. Important conditions for obtaining reliable results are the constant fixation of the gaze of the subject on the central mark, as well as a stable speed of movement of the test object (about 2° per 1 s). The study is performed without glasses to exclude the influence of the edges of the spectacle frame on its results.

Mainly used manual perimetry, although modern computerized perimeters, detailed in the next section, have programs for kinetic perimetry.

Manual perimetry is carried out using Foerster-type perimeters (for example, PNR-2-01), which is a black arc rotating about the center to be installed in the required meridian, along which a test object is moved in the form of a circle of white or another color at the end of a black rod. More convenient projection perimeters. In Russia, an arc perimeter is produced - an analyzer of the projection field of view APPZ-01 (a modification of the previously produced PRP-60). A number of foreign firms offer hemispherical perimeters (of the Goldman type).

Projective, especially hemispherical perimeters provide standardization of the brightness of the background and the test object, which somewhat increases the accuracy of the study. In addition, by using test objects of several sizes (and/or brightness levels - on hemispherical perimeters), it is possible to obtain a more complete, complex assessment of the state of the visual field boundaries. This technique - the so-called quantitative (quantitative) perimetry allows, in essence, to determine the boundaries of several sections of the "island of the visual field" at different levels from its base. However, this increases the duration of the study several times.

Currently, in patients with glaucoma, kinetic perimetry is of limited importance, providing mainly control of the state of the boundaries of the visual field. In most cases, this method can determine already significant changes in the initial stage or with the progression of the disease. With regard to the early diagnosis of glaucoma or the detection of non-sharp phenomena of disease progression, manual kinetic perimetry is significantly inferior to static one and should be used only as an auxiliary method, or in conditions where computer static perimetry remains unavailable for one reason or another.

Method static perimetry consists in determining the light sensitivity in different parts of the field of view using fixed objects of variable brightness. The study is carried out with the help of computerized devices that provide the study in a semi-automatic mode; such a modification of the method was given the name of computer or automatic static perimetry.

There are computer perimeters from many manufacturers on the medical market. However, Humphrey perimeters from Carl Zeiss Meditec and Octopus from Haag-Streit are recognized as reference for examining patients with glaucoma (below, they are conventionally called standard perimeters).

Currently produced computer perimeters usually have 25-30 programs, in accordance with which the research process is carried out. At the same time, the program sets the localization of the studied points in the field of view, the size, brightness and sequence of presentation of the test objects used.

Programs implement certain research strategies, the main of which are threshold and suprathreshold (screening); their combination is also possible. The threshold strategy is to determine the threshold of light sensitivity at each point in the field of view under study; it is the most accurate, but it requires a lot of time and a long strain of the patient's attention, which is not always feasible. With the above-threshold strategy, the fact of a decrease in light sensitivity relative to its expected level (statistical average, or calculated based on the measurement of light sensitivity in a small number of points in a particular patient) is recorded. Using such a strategy can significantly reduce the duration of the study, but its accuracy is also much reduced. Some suprathreshold programs at points of decreased photosensitivity additionally make a rough estimate of the degree of reduction, dividing scotomas into absolute and relative. The only mass-produced automatic static perimeter in Russia carries out research only according to the above-threshold strategy; the device defines scotomas as absolute and relative, which, in turn, are divided into 2 levels.

Compromises are also possible. One of them is combined programs that provide for an above-threshold study of the entire field of view, followed by determination of the sensitivity threshold in the areas of its decrease. Another option is the use of special algorithms that reduce the time of the threshold study by optimizing many of its elements. In the Humphrey perimeter, these are the SITA Standard and SITA Fast algorithms, in the Octopus perimeter, the TOP algorithm. Taking into account a significant (3-4 times) reduction in the study time, the use of these algorithms should be considered justified, despite a slight decrease in the accuracy of the study.

In glaucoma, threshold programs are used as standard for examining the central region of the visual field (30-2 or 24-2 on the Humphrey perimeter or programs 32 or G1 on the Octopus perimeter).

The study is carried out monocularly. When examining the central visual field in patients over 40 years of age, an age-appropriate presbyopic corrective lens is used. With ametropia, a correction is made equal to its spherical equivalent. The power of the corrective lens can also be calculated by the perimeter itself after entering data on the age of the subject and the results of refractometry. The lens should be positioned close enough to the patient's eye so that its edges do not restrict the field of view and do not create false scotomas. False scotomas are also associated with the presence of ptosis or "hanging" of the eyebrow. In such cases, the palpebral fissure can be widened with a strip of adhesive tape. The built-in video camera allows you to accurately position the patient's eye, as well as measure the diameter of the pupil. The optimal pupil size is 3.5-4 mm. With a very narrow pupil of less than 2 mm, weak mydriatics may be used in some cases. However, the presence of mydriasis is also undesirable, as it is accompanied by an increase in photosensitivity, which can lead to erroneous conclusions. At the first examination of the patient, it is necessary to carefully instruct him and conduct a trial (demo) test in order to reduce the role of the “learning effect”.

Evaluation of the correctness of the test.

There are a number of indicators that allow you to evaluate the quality of the test performed by the patient. Errors (errors on Humphrey, catch trials on Octopus) can be false positive when the patient responds without a stimulus, reacting to the sound of the projection mechanism, and false negative when a brighter test object is missed at the point where the patient had previously saw a less bright stimulus. The presence of a large number (20% or more) of errors of one kind or another indicates a low reliability of the results obtained. The Octopus perimeter also gives the total reliability factor (RF - reliability factor), reflecting the total number of errors in%.

The Humphrey perimeter also periodically checks for correct fixation by applying a stimulus to the blind spot and recording Fixation Losses when the patient responds to a stimulus that he should not have seen; the proportion of fixation losses should not exceed 20%. In addition, constant registration and recording of deviations in the direction of gaze is carried out. With their large amplitude and frequency, the data are also unreliable. Gaze deviations are not registered in the Octopus perimeter, but suspend the program execution until the correct position of the eye is restored.

Evaluation of results.

The printout of the test results contains a large amount of information characterizing the state of the central visual field. An example of a Humphrey perimeter printout is shown in Figure 2. A black and white or color (Octopus) map reflects the light sensitivity graphically. Schemes with applied numbers demonstrate quantitative indicators of photosensitivity and their deviations from the age norm. The most informative are the two lower paired schemes "Total deviation" and "Pattern deviation" on Humphrey, "Probability" and "Corrected probability" on Octopus, which are almost equivalent in both perimeters. These schemes demonstrate the probability of the presence of certain deviations in the norm; the lower the probability of deviation, the more intense the shading of the corresponding symbol. The most important are the last (right) of the considered pair schemes - "Pattern deviation" and "Corrected probability". In these schemes, the influence of a diffuse general decrease in photosensitivity, which occurs, for example, in the presence of an initial cataract or other opacities in the optical media of the eye, is excluded. Thus, even minor local defects are highlighted, which play an important role in the early diagnosis of glaucoma. In other circuits, such small changes often go unnoticed.

Along with the schemes, the printouts also contain a number of summary indicators (indices) that give a general quantitative characteristic of the state of the central field of vision (where the names of the indices on the two perimeters differ, the first is the name for Humphrey, the second, after the sign "/" - for Octopus).

1. MD - mean deviation (mean deviation) - reflects the average decrease in photosensitivity.

2. PSD - pattern standard deviation (standard deviation (sigma) of the pattern [central field of view]) / LV - loss variance (loss variance [sensitivity]) - characterizes the severity of local defects.

3. SF - short term fluctuation (short-term fluctuations, only Humphrey) - indicates the stability (repeatability) of photosensitivity measurements at points that were checked twice during the study. SF>7.0 dB is considered as a sign of unreliability of the obtained results.

4. CPSD - corrected PSD / CLV - corrected LV - PSD / LV values ​​corrected for short-term fluctuations (see item 2).

(When using the SITA Standard and SITA Fast algorithms, the CF and CPSD indices are not indicated)

On the perimeter of Humphrey, the probability of having a given index value is normal. For example, the entry "MD -9.96 dB P<0.5%» указывает, что снижение индекса MD на 9,96 дБ встречается реже, чем в 0,5% (то есть реже, чем у 1 из 200 здоровых лиц).

Total indices, especially the first two of them, are used mainly in scientific research, and also, in individual patients, when assessing the dynamics of changes. However, in general, they are much less informative than the "Pattern deviation" or "Corrected probability" schemes.

The Humphrey perimeter printout also contains the result of the GHT –Glaucoma Hemifield Test – Glaucoma hemifield test (comparison of the upper and lower hemifields in 5 corresponding areas) in the form of messages: GHT within / outside normal limits (within / outside the norm) or GHT borderline (on the borderline level).

The Octopus perimeter printout includes a Bebie Curve, also called the Cumulative Defect Curve. On the curve, from left to right, the photosensitivity of all points is successively plotted from the highest to the lowest. This curve, if it is evenly reduced relative to the norm curve, indicates the presence of a general (diffuse) decrease in photosensitivity. In the presence of local defects, the left edge of the curve remains at a normal level, while the right edge sharply deviates downward.

Significant criteria for establishing the diagnosis of glaucoma are the following:

1. Pathological Hemifield Glaucoma Test (GHT) - on two consecutive visual field tests, or

2. the presence of three points with a decrease in photosensitivity, which has a probability P<5%, а хотя бы для одной из этих точек P<1%, при отсутствии смыкания этих точек со слепым пятном (указанные изменения также должны иметь место при двух последовательных проверках поля зрения);

3. increasing the variability (corrected standard deviation) of the central visual field (CPSD) pattern, having a probability P<5% при нормальном в остальных отношениях поле зрения (также должно наблюдаться при двух последовательных проверках поля зрения).

As glaucoma progresses, changes in the central visual field increase and can be detected not only with the help of computer static perimetry, but also with campimetry and with careful examination of the corresponding parts of the visual field using kinetic perimetry methods. Often characteristic defects are found in the area located 10-20 ° from the fixation point (the so-called Bjerrum zone), in the form of focal or arcuate scotomas, which can merge with the blind spot. Somewhat less often, there is an isolated expansion of the blind spot or small scotomas within 10° from the point of fixation. The so-called “nasal step” can be observed, which manifests itself in the form of a scotoma in the upper nasal (less often lower nasal) parts of the central visual field, strictly limited by the horizontal meridian (in the Humphrey perimeter it is also detected using the Glaucoma hemifield test). A similar horizontal boundary is often noted among arcuate scotomas in the Bjerrum zone.

Evaluation of the dynamics of the field of view. One of the most important signs of the progression of the glaucoma process is the negative dynamics of the visual field. To assess it, most perimeters, including standard perimeters, contain special programs. A sufficiently reasonable judgment about the nature of changes in the visual field provides a comparison of at least three, and preferably 5-6 consecutive measurements (taking into account the subjectivity of the study, including the "learning effect"). To ensure comparison, all studies must be carried out strictly according to the same program. Repeated studies should be carried out 2 times a year.

There are no strict criteria for assessing the progression of glaucoma in the field of view. However, it is believed that a decrease in the photosensitivity of a group of points in one half-field by 5 dB or more, or one point by more than 10 dB, confirmed during two consecutive checks of the field of view, indicates a significant deterioration. In addition, each perimeter has its own criteria. For example, in the Humphrey perimeter, Glaucoma Change Probability Maps evaluates and symbolizes each point where there is a significant decrease in photosensitivity. It is believed that the presence of three such (same) points at three consecutive examinations clearly confirms the progression, and at two examinations serves as the basis for a presumptive conclusion.

Blue-yellow perimetry, also called Short Wavelength Automated Perimetry (SWAP), is available on standard and some other modern perimeters. Outwardly, it differs from the usual (white-on-white "white-on-white") perimetry only by the use of a yellow background color (100 cd/m?) and blue color stimuli (maximum in the region of 440 nm, size V according to Goldman). However, these stimulation conditions make it possible to isolate and separately evaluate the function of the so-called "blue" cones, as well as the ganglion cells corresponding to them (small bistratified) and the overlying sections of the visual pathways.

It has been shown that blue-yellow perimetry provides the earliest detection of visual field changes in glaucoma. At the same time, the method is very sensitive to defocusing, clouding of the optical media of the eye and therefore has a slightly lower specificity (reliability) than conventional static perimetry. The increased variability in results makes it difficult to assess the progression of glaucoma. In addition, algorithms that reduce the study time (such as SITA or TOP) have not been implemented, so blue-yellow perimetry requires a significant amount of time, which limits its use in practice.

Frequency doubling technology perimetry (FDT perimetry) is based on the optical illusion that a black and white grating alternating (changing the color of black stripes to white and white stripes to black) with a certain frequency creates the illusion of presence twice as many lanes. This illusion is used in the original device - Humphrey FDT perimeter by Carl Zeiss Meditec. The device examines a central field of view of 20° (program C-20; extension up to an additional 30° from the nasal side is possible - program N-30). 16 stimuli are used in the form of 10° squares, 4 in each quadrant and the 17th in the form of a 5° circle in the center (Fig. 3). The stimulus duration was 720 ms, the spatial frequency of the grating with a sinusoidal illumination profile was 0.25 cycles per degree, the alternation frequency was 25 Hz, and the average brightness was 50 cd/m?. The contrast of the grating changes sequentially until the subject notices it. Just as in conventional static perimetry, suprathreshold and threshold strategies are used. It is important that the suprathreshold study takes only 35 seconds, and the threshold study takes 3.5-4 minutes. The speed of the study, as well as a weak dependence on defocusing and pupil size, make it possible to use the method and the device for screening studies for glaucoma. I use two versions of the screening program C-20-1 and C-20-5, differing in that in the first case, 99%, and in the second case, 95% of healthy people notice gratings at the initial level of contrast. High sensitivity and specificity of the method in the diagnosis of glaucoma is shown; good agreement of the obtained results with the data of conventional static perimetry.

Campimetry refers to the simplest and oldest methods of studying the visual field. It was widely used in our country for the early diagnosis of glaucoma in the 40-70s of the last century.

Campimetry requires a flat black surface 2 × 2 m in size with uniform illumination. The patient is seated at a distance of 1 m from this plane with the unexplored eye closed and asked to fix a mark in the form of a light circle or cross in the center of this surface. Then a test object in the form of a white circle with a diameter of 5 mm on a long dark stick is led from the periphery to the center in different meridians and the place where the mark appears is marked with chalk or a pin. The boundaries of the field of view obtained in this way are recalculated into angular degrees. To do this, measure the distance from the fixation point to the chalk mark in centimeters and divide it by 100. This is the tangent of the angle at which the patient sees the object. Then, using logarithmic tables, you need to find the value of the corresponding angle by its tangent.

In practice, a campimeter with two pantographs (for the right and left eyes) by Professor A.I. Humpback with a transparent protractor V.S. Krasnovidov for determining the angular dimensions of cattle without recalculations and a campimeter from Bausch & Lomb.

Diagnosis of congenital glaucoma.

When examining a child with congenital glaucoma, attention should be paid to the following signs characteristic of this disease.

Edema of the cornea. More often it is represented by microcystic edema of its epithelium, less often (with ruptures of the posterior border plate) - by pronounced edema of the stroma. Congenital glaucoma is characterized by asymmetry of edema in paired eyes.

To differentiate corneal edema on the basis of congenital glaucoma from physiological corneal opalescence similar in external signs (in the first weeks of a child's life), the following method should be used. 1-2 drops of an osmotic preparation (40% glucose solution, glycerin, etc.) are instilled into the conjunctival cavity of the examined eye. If the clouding of the cornea is associated with its edema (due to congenital glaucoma), then its density will decrease, or the clouding will disappear altogether. If this procedure does not change the density of corneal opacity, then its cause lies in the physiological opalescence of the cornea of ​​​​the newborn, which will disappear on its own in a few days.

Stretching of the cornea. The value of the horizontal diameter of the cornea, exceeding 9.5 mm in newborns and 11.5 mm in two-year-old children, indicates its stretching.

Differentiate stretching of the cornea with megalocornea. In children with congenital glaucoma, the process of corneal stretching is usually asymmetric in paired eyes. On the cornea, they often show traces of ruptures of the posterior border plate (the so-called Gaaba striae). In addition, for the disease in question, stretching of the limbus is more characteristic. And, finally, further stretching of the cornea, registered according to the results of dynamic observation, inclines the doctor to the diagnosis of congenital glaucoma.

Reflex lacrimation and photophobia are the result of microerosion of the epithelial surface of the cornea, which occurs on the basis of increasing edema and epithelial bullosis.

Clinical refraction of the eye of a child with congenital glaucoma is often myopic. An increase in the degree of myopia is characteristic, as the glaucoma process progresses.

The considered relationship between congenital glaucoma and myopia has another practically significant aspect: when examining children with myopia, attention should be paid to the possibility of their having congenital glaucoma, which results in the development of symptomatic myopia.

An increase in the depth of the anterior chamber, with a sluggish pupil reaction to light, serve as additional confirmation of the development of the glaucoma process in the eye.

An increase in ophthalmotonus (or its asymmetry in paired eyes) of a newborn indicates the presence of congenital glaucoma. At the same time, it becomes possible to reliably measure the intraocular pressure in a child in the first months of life only under anesthesia: the traditional palpation study of IOP, as a rule, is not informative. The measurement of ophthalmotonus using a pneumotonometer or an IHD tonometer is very problematic due to the altered elasticity of the stretched cornea and sclera.

Excavation and "stretching" of the optic nerve head are important signs of the glaucoma process, allow us to assess its severity and functional prospects for the treatment of a child with congenital glaucoma.

Gonioscopy allows you to supplement the information obtained during the clinical examination of the child. Usually it is possible to visualize mesodermal tissue in the angle of the anterior chamber, as well as signs of goniodysgenesis of the iridocorneal angle. Taking into account the fact that in most cases gonioscopy in young children is feasible only under anesthesia, it is advisable to plan it simultaneously with a surgical operation (focused on the results of gonioscopy).

Echobiometry supplements information about the progression of the glaucoma process by recording the rate of physiological growth (or stretching in glaucoma) of the eyeball.

Refractometry also makes it possible to indirectly assess the dynamics of the expansion of the fibrous capsule of the eye, which is evidenced by a gradual increase in the clinical refraction of the eye from hypermetropia to myopia.

In general, the considered directions of complex diagnostics of congenital glaucoma are quite effective. Of particular importance is the asymmetry and negative dynamics of the detected changes, which testify in favor of glaucoma. Of course, when examining children with congenital glaucoma, diagnostic information allows supplementing other instrumental methods for assessing IOP, the optic nerve head, and other structures of the organ of vision. However, in young children they are applicable only under conditions of anesthesia and therefore require justification for their use.

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• Diagnosis of glaucoma

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  * "Pericom" is a hemisphere with a total number of presented test objects - 206 (central field of view - 152, peripheral - 74). The device has the following research programs: “central field of view”, “total perimetry”, “glaucoma”, “peripheral field of view”, “macula”, “special screening”, etc. For the first three programs, you can choose the scope of the study: “quick screening” (the volume of the study is about 30% of the total volume of test objects in the selected mode); “reduced screening” (about 70% of the total); "all points" (100%). In addition, the program "special screening" offers the following expansion of ongoing research - "nasal border", "parcentral focal and arcuate scotomas", "nasal step", "temporal defect", "study of the blind spot".

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The study of the organ of vision begins from the moment the patient appears on the threshold of the office. If the patient enters with his head down and his eyes closed (more often children), then he is afraid of the light. This happens with inflammatory diseases of the eyes, causing severe photophobia.

If the patient enters with his head thrown back, with his eyes wide open and his arms outstretched forward, turning his head in different directions, this indicates that the person is looking for light.

With a narrowed field of vision, the patient confidently goes to the doctor, but along the way he stumbles upon large objects. It is necessary to pay attention to the height of the patient, his physique, as well as to the tabetic, cerebellar, hemiplegic gait.

The examination begins with the clarification of the patient's complaints. They are sometimes very characteristic and allow you to immediately make a presumptive diagnosis or orient yourself regarding the localization of the process. The most common complaints are a decrease in visual acuity, a variety of symptoms: “fog” before the eyes, “flies” or haze in the eyes, “spot” before the eye, “lightning”, “zigzags”, double vision, dryness, pain, sensation of a foreign body, burning, redness, suppuration, swelling, pain, etc. When complaining of pain, one should pay attention to its nature, localization, intensity, irradiation, time of appearance. If the patient complains of swelling, then it is necessary to find out what he associates it with, how quickly it increases or remains unchanged, if it decreases, then at what time of day.

Then a detailed history is collected. In younger children, the history is reported by the parents. When collecting an anamnesis, you should find out: the disease began acutely or developed gradually, the timing of its onset, factors preceding and accompanying the disease (injury, physical and chemical damage, stress, use of drugs, injections, poisoning, etc.).

If there was an injury, then was there a loss of consciousness, vomiting, what kind of help was provided, what kind of transport the patient was taken to.

With a number of eye diseases, it is necessary to clarify the family history. In case of familial hereditary diseases, the presence of such diseases is ascertained, the age at which it began. They pay attention to the transferred general diseases (rickets, tuberculosis, syphilis), eye diseases, as well as the condition of the teeth, paranasal sinuses, etc. It is also necessary to find out working conditions, life, occupational hazards.

Examination of the organ of vision requires strict thoroughness, consistency and consistency. An external examination begins with an examination of the brain and facial skull. Attention is drawn to the shape, dimensions of the head and facial skull, to the symmetry of the right and left halves of the face and its individual parts.

Asymmetry may be the result of a "retraction" of the orbit, due to a decrease in the upper jaw, while the entire half of the face may be reduced. "Retraction" of the orbit may be associated with a decrease in the volume of the eyeball or its absence, especially in childhood. Asymmetry of the face may be associated with edema and swelling of the soft tissues. The superciliary region, the side wall and back of the nose, the anterior wall of the upper jaw, the zygomatic bone, the temporal region and the region of the salivary glands are examined with the determination of the absence or presence of any anomalies.

If there is swelling in the area of ​​the parotid gland, it is necessary to determine by palpation its consistency (soft, dense), the area of ​​distribution, soreness, adhesion to the underlying tissues, the mobility of the skin in the area of ​​swelling, the presence of softening, fluctuations, the reaction of regional lymph nodes.

If a tumor process is suspected, special attention is paid to the consistency, size, and nature of the surface (smooth, bumpy). Changes in the parameters and course of the process can sometimes indicate a disease of the organ of vision.

A wide and low nose bridge contributes to the development of diseases of the lacrimal ducts; saddle-shaped form of a sunken nose, scars at the corners of the mouth, excessive development of the frontal tubercles with a deep depression between them - an indicator of syphilis.

The face is a mirror of health and disease. Looking at the patient's face, one can tell what he is sick with (a disease of the lungs, heart, kidneys, liver, endocrine glands, etc.). It is important to pay attention to the change in complexion. A pale face is observed with anemia, a cachectic color - with malignant tumors, red spots on the cheeks - with tuberculosis patients, an ecteric color - with liver diseases, an earthy color of a puffy face, thick greasy skin - with chronic alcohol poisoning, an earthy color - with kidney diseases, cyanotic face - with mitral stenosis, systemic lupus erythematosus, rosacea. Cyanosis is central and peripheral. Central - on the lips, tongue.

The main causes of central cyanosis are lung disease, respiratory failure, congenital heart defects with right-to-left shunting of blood.

Peripheral cyanosis occurs with heart failure, stenosis of the arteries, with cooling of the hands, tip of the nose, earlobe, and feet. Red full-blooded faces are observed with polycythemia, with Cushing's syndrome. Hyperpigmentation of the skin occurs with Addison's disease, thyrotoxicosis, hemochromatosis, liver cirrhosis, porphyrinuria, chronic renal failure, pregnancy, melanoma, while taking certain medications.

The face changes greatly in mental and nervous diseases. A mask-like, motionless face is noted in Parkinson's disease.

The face of a patient with hypothyroidism is puffy, the eyelids are swollen, the skin is dry, the hair is thin, dry, sparse.

With central paralysis of the facial nerve, there is a smoothness of the nasolabial fold and a drooping of the corner of the mouth on the side opposite to the lesion, and with peripheral paresis, weakness of the muscles of the entire half of the face.

When the face is deformed, it is noted which anatomical formations change (jaws, eyelids, nose, cheeks, lips, etc.) and what these changes are expressed in.

The edges of the orbit are examined by palpation. Isolated diseases of the orbital margin are rare, as they quickly move to the walls of the orbit. On the orbital edge, there may be periostitis, carious processes, gummas, true tumors, etc.

In children, changes in the region of the orbit can be congenital (dermoid cysts, the favorite location of which is the temporal cavity at the end of the eyebrow), as well as with cerebral hernias or tumors (angiomas, sarcomas, etc.).

Then the position of the eyeball in the orbit is examined, which in the normal state almost does not protrude from it and is located somewhat closer to the outer edge. In pathology, the eyeball can move forward (exophthalmos), back (enophthalmos) and there may be its lateral displacement.

The protrusion of the eyeball from the orbit is determined using devices - exophthalmometers. Hertel's mirror exophthalmometer has found the widest application in the clinic.

According to many authors, the average protrusion of the apex of the cornea is 16.6-17.0 mm, in women it can be 1.4 mm less, in men 1.5 mm more than the average values. In children under 4 years old, the average eye protrusion is 10-13 mm, at 20-24 years old - 17.46 mm, at 25-60 years old - about 17.

Hertel's mirror exophthalmometer is a horizontal plate graduated in millimeters with divisions, on each side of which there are 2 mirrors intersecting at an angle of 45 °. The device is tightly attached to the outer arcs of both orbits. In the lower mirror, the profiles of the corneas are visible, and in the upper one there is a measuring ruler, by which the distance of each eye is determined in millimeters. The difference in the position of the apex of both corneas will determine the presence and degree of exophthalmos in the diseased eye. To perform exophthalmometry in dynamics, it is necessary to take into account the distance between the outer edges of the orbit, at which the measurement was first performed. The amount of protrusion of the eyeballs decreases after 60 years, because. atrophy of the intraorbital adipose tissue occurs, and it is equal to 15 cubic millimeters.

Exophthalmos can occur with thyrotoxicosis, edematous exophthalmos, orbital tumors, etc. Unilateral exophthalmos may be due to the germination of the tumor of the upper jaw in the orbit. Lateral displacement of the eyeball in combination with exophthalmos is associated with the presence of neoplasms, cysts, abscesses, hematomas, etc.

The degree of protrusion of the eyeball can be from barely noticeable to dislocation of the eyeball from the orbit.

Enophthalmos is sometimes observed with severe general exhaustion, in these cases it is bilateral. Unilateral enophthalmos can be with Horner's syndrome (sympathetic nerve dysfunction), with a violation of the integrity of the bones of the orbit. With traumatic enophthalmos, there is often a simultaneous lateral displacement of the eyeball. The degree of enophthalmos can be different.

The volume of eye movements is determined monocularly and binocularly.

With the simplest method of studying eye movement, the subject is asked to follow the object as it moves up, down, left and right (the head remains motionless). Normally, with the maximum deviation of the eyeball outwards, the outer edge of the cornea should reach the outer commissure of the eyelids, inwards - to the area of ​​the lacrimal caruncle, downwards - the eyelid covers more than half of the cornea, upwards - the cornea is covered by the upper eyelid approximately 2 mm.

Movement disorders are especially visible with normal movement of the other eye. At extreme positions of the eyeball, it is sometimes possible to detect nystagmus - horizontal or rotatory.

When determining the associated eye movement, the patient is asked to look in all directions without fixing on any object or they bring a finger with a request to look at it, without indicating the side from which the finger is brought. If the associated eye movements are disturbed, which occur with gaze paralysis, the patient cannot look with both eyes in the indicated direction, and each eye moves freely behind the object.

When examining convergence, the patient is forced to look at the doctor's fingertip, which is brought closer to his eyes strictly along the midline up to 20 cm. In pathology, the visual lines deviate from the point of fixation already at distances far from the eyes, while normally the visual lines deviate only at a close distance from the eyes.

Eyelids Next, proceed to the study of the century. But since the top border of the upper eyelid is the eyebrow, you should, first of all, pay attention to the eyebrows. They are a protective formation that traps sweat, dust and dirt particles. There may be a lack of hair on the eyebrows, depending on general diseases (syphilis, leprosy) or local ones (eczema, seborrhea). Hair loss of the outer part of the eyebrows is observed with hypothyroidism. There is a graying of the eyebrows that is not age-appropriate, which is associated with damage to the nervous system. In the area of ​​the eyebrow, there may be boils, carbuncles, abscesses, dermoid cysts, which are more often localized at the outer end of the eyebrow, at the suture line between the frontal and zygomatic bones.

When examining the eyelids, it is necessary to evaluate their shape and position. There may be a congenital complete absence of the eyelid or a coloboma that resembles a cleft lip (cleft lip). But the coloboma of the eyelid can also be acquired (when the eyelid is injured). May be observed: shortening of the century; lunate fold of skin hanging over the inner commissure of the eyelids (epicanthus). The eyelids should rest with their lower back surface against the eyeball.

There may be an eversion of the eyelid, when the back surface lags behind the eye, or, conversely, an inversion of the eyelid, when the skin surface of the eyelid along with the eyelashes touches the eye. Eversion of the eyelid occurs as a result of scarring of the skin on the outer surface of the eyelid, sometimes blepharospasm leads to eversion of the eyelid in acute diseases that occur with great eye irritation. But eversion can appear with paralysis of the facial nerve due to a weakening of the tone of the orbicular muscle, with senile weakness of the circular muscle and flabbiness of the skin of the eyelid. The cause of the inversion of the eyelids is most often cicatricial wrinkling of the mucous membrane. Prolonged spasm of the eyelids, as well as senile weakness of skin tissues, can also lead to volvulus.

When examining the anterior surface of the eyelid, it must be remembered that the skin of the eyelid is very thin, especially in children of the first year of life, devoid of subcutaneous fatty tissue. It is necessary to pay attention to the presence of swelling, redness, cracks, edema, depigmentation of the skin of the eyelids (vitiligo) or, conversely, increased pigmentation (with Addison's disease, hypothyroidism, during pregnancy, etc.).

It is necessary to determine the nature of the edema (inflammatory or non-inflammatory). Inflammatory edema can occur during an inflammatory process in the eyelid itself, in the conjunctiva of the eyelids and the conjunctiva of the eyeball (chemosis), in the area of ​​​​the lacrimal sac or lacrimal gland, the eyeball itself (infected wounds of the eye, including panophthalmitis, in the orbit or in the surrounding its paranasal sinuses and tissues surrounding the eye). Inflammatory edema of the eyelids is observed with phlegmon of the infraorbital-zygomatic region, which extends to the lower and sometimes the upper eyelid, with phlegmon of the buccal region, in which such a strong edema of the lower and upper eyelids is revealed that the palpebral fissure narrows or completely closes.

Non-inflammatory edema occurs with heart failure, kidney disease, but edema in these diseases is more pronounced in the morning and captures the eyelids of both eyes. Non-inflammatory edema includes edema in allergic conditions (angioedema angioedema). Subcutaneous emphysema simulates edema, but crepitus is felt with it. It is necessary to pay attention to the possibility of having any education. It can be xanthelasma, nevus, angioma, myoma, fibroma, neurofibroma, dermoid cyst, wart, cancer, or sarcoma.

The palpebral fissure is examined, which is outlined by the free edges of the upper and lower eyelids. Normally, with a calm look forward, its length is 3-3.5 cm, width in the central part is 1.5 cm. The lower edge of the eyelids touches the lower edge of the cornea, the upper edge covers the upper part of the cornea by 1.2 mm.

It turns out if there is a unilateral narrowing of the palpebral fissure, which can be with the drooping of the upper eyelid (ptosis) due to weak activity of the muscle that lifts the upper eyelid (m. levator palpebrae superior), due to paresis of the oculomotor nerve. The narrowing of the palpebral fissure can be with spastic blepharospasm due to inflammatory diseases of the conjunctiva, cornea and other diseases that cause photophobia.

There are cases of congenital narrowness of the palpebral fissure, caused by any features of the neuromuscular apparatus of the eye.

Sometimes there is a peculiar combination of ptosis in one eye, which disappears along with the opening of the mouth and the abduction of the lower jaw to the side opposite to the side of the ptosis. This is the Marcus-Gunn syndrome, it appears after a traumatic brain injury, tooth extraction, damage to the facial nerve, etc.

Or maybe the opposite phenomenon, i.e. when opening the mouth, the normal eyelid of one eye drops and comes into a state of ptosis. This is the Martin-Am syndrome, which occurs during the period of restoration of the function of the facial nerve after paralysis of the facial muscles.

It is necessary to see if there is an increase in the palpebral fissure, which may be the result of paralysis of the facial nerve (p. Facialis) - paralytic lagophthalmos - or as a manifestation of irritation of the sympathetic nerve (in the latter case, a slight expansion of the palpebral fissure is observed).

Examining the free edge of the eyelids, pay attention to the location of the eyelashes - is there any abnormal growth (trichiasis), in which part of the eyelashes or all of the eyelashes grow towards the eyeball, causing irritation, growth in several rows (polytricias), and sometimes in two rows, moreover, the second row is located at the site of the excretory ducts of the meibomian glands (districhiasis), reduction or complete absence of eyelashes (madarosis). Madarosis can be associated with local damage to the hair follicles, as well as inflammatory changes in the skin at the base of the eyelashes in some common diseases (syphilis, Basedow's disease, poisoning with arsenic and other poisons). A careful examination of the skin of the eyelids at the root of the eyelashes can reveal its redness, the presence of scales that are easily removed with a damp cotton swab or difficult to remove crusts. Reddening of the skin of the free edge of the eyelid can also be associated with inflammation of the meibomian glands. At the edge of the eyelid, a limited painful reddish swelling may develop, at the top of which a yellowish head forms after 2-3 days, when the latter is opened, pus comes out. This is an inflammation of the sebaceous gland or hair follicle of the eyelashes - external barley (hordeolum).

Sometimes, in the thickness of the eyelid, a limited, dense, painless formation, not soldered to the skin, is felt - a chalazion. Chalazion is a chronic inflammation of the meibomian gland. Painful, reddened, dense, thickened the entire eyelid as a whole can be with meibomitis - a common purulent inflammation of many meibomian glands.

The sensitivity of the skin of the eyelid is investigated: tactile, thermal and pain sensitivity. To determine tactile sensitivity, light touches with a piece of paper, brush, hair are sufficient, for thermal - with a thermoanesthesiometer, for pain - light pricks with a pin. Pathological disorders of sensitivity are expressed by anesthesia or hyperesthesia.

With a central lesion, the changes will affect both eyelids, with a peripheral lesion, only one eyelid. Soreness with pressure on the region of the infraorbital fissure and the region of the canine fossa indicates damage to the first (n. ophthalmicus) and second (n. maxilaris) branches of the trigeminal nerve.

After examining the eyelids, the lacrimal organs are examined: the lacrimal gland, the lacrimal openings, the lacrimal canaliculi, the lacrimal sac, the lacrimal-nasal canal.

Studies of the lacrimal glands are reduced to a simple external examination and palpation. An increase in the size of the lacrimal gland leads to deformation of the palpebral fissure - the edge of the upper eyelid takes the form of a recumbent letter S. Normally, only its palpebral lobe is accessible for inspection, which is visible after eversion of the upper eyelid, in the form of a protruding lobed-tuberous formation above the upper outer part of the eyeball when viewed downward and inward . It has a soft texture.

The orbital part of the lacrimal gland is not accessible for inspection and palpation.

If a neoplasm of the lacrimal glands is suspected, X-ray, angiography, thermography, radionuclide studies, computed tomography, synthography, and, if indicated, puncture biopsy are performed for diagnosis.

To study the secretory function of the lacrimal glands, a Schirmer test is performed. For setting the sample, special strips of filter or litmus paper 5 mm wide and 35 mm long are taken. The working end of the strip (5 mm) is bent at an angle of 40-45° and placed in the temporal outer third of the orbit and slightly upwards is laid behind the lower eyelid. The patient should close their eyes. In this case, the strip should not touch the cornea, but only the inflection - the edge of the eyelid. After 5 minutes, the length of the wetted part of the strip should be at least 15 mm. If less, this indicates hypofunction of the lacrimal glands. With hypofunction of the lacrimal glands, biomicroscopy shows thinning, discontinuity of the lacrimal stream, ruptures of the precorneal tear film, desquamated epithelium and nitmucin on the surface of the cornea. Normally, the width of the lacrimal stream is 0.1-0.25 mm.

Hyposecretion of the lacrimal gland congenital

Lacrimal gland aplasia, anhydrotic ectodermal dysplasia, isolated neurogenic hyposecretion, aplasia of the lacrimal nerve nucleus, complex neurogenic hyposecretion, lacrimal autonomic dysfunction (Riley-Day syndrome), cystic fibrosis.

Acquired

Senile atrophy of the lacrimal gland.

Isolated injury, inflammatory, neoplastic disease of the lacrimal gland.

Systemic lesions of the lacrimal gland (Sjögren's syndrome, rheumatoid arthritis, benign lymphomyeloepithelioma of the parotid lacrimal gland (Goodwin), sarcoidosis, arthropathic psoriasis, systemic lupus erythematosus, scleroderma, periarteritis nodosa, amyloidosis, leukemic infiltration, AIDS, graft versus host syndrome.

Neurogenic hyposecretion

Damage to the VII cranial nerve, n. petrosus mayor, pterygopalatine node, common branch n. lachrymalis.

Drug-tonic hyposecretion

Atropine, botulism, B-blockers, ovulation inhibitors, condition after partial or complete dacryectomy, psychogenic hyposecretion.

Accelerated drying of the tear film

Exophthalmos, lagophthalmos, ectropion, impaired blinking reflex, mechanical immobilization of the eyelids, acute conjunctivitis due to local hypothermia, climacteric factors.

The study of the lacrimal ducts begins with an examination of the lacrimal openings, paying attention to their size, shape and position. If the lower lacrimal opening becomes visible in the subject when looking up, this indicates her eversion, which may be associated with atony. For better detection of mild atony and the associated mild eversion of the inferior lacrimal opening, the patient should be asked to look outside, because. at the same time, the lag of the edge of the eyelid from the eyeball increases. After pulling back the lower eyelid, the flabby eyelid returns to its original place slowly and does not fit snugly against the eyeball.

The size of the lacrimal opening normally does not exceed 0.5 mm, with a diameter of 0.25 mm it is considered narrowed. If the lacrimal opening is sharply narrowed and poorly visible, it should be stained with collargol, and it will become more noticeable. Expansion of the lacrimal opening with stretching, hyperemia of the skin along the tubule - these are signs of canaliculitis. Of the congenital anomalies of the lacrimal openings, there can be narrowing, atresia, underdevelopment of the lacrimal opening, deformation and splitting of the lacrimal opening, dislocation of the lacrimal openings, and of the acquired changes, narrowing of the lacrimal opening, infection, eversion of the inferior lacrimal opening, senile hypertrophy of the lacrimal papillae should be noted.

When examining the lacrimal lake, attention is paid to its filling with tears, the state of the lacrimal caruncle and the semilunar fold, whether there are any hypertrophic, inflammatory changes that affect the depth of the lacrimal lake and the physiological conditions for draining tears from it.

When examining the lacrimal ducts, it should be remembered that there may be congenital anomalies of the lacrimal ducts or in combination with changes in the lacrimal openings, or an independent anomaly - elongation of the lacrimal ducts, diverticula of the ducts. Of the acquired canaliculitis, it should be noted acute canaliculitis and chronic, caused by various pathogenic agents. There may be granulation canaculitis, more often this is the outcome of mucosal damage during probing, washing the lacrimal ducts, lacrimal duct cysts, benign neoplasms (polyp, papilloma), malignant (basalioma, squamous cell carcinoma).

As a result of contusions, wounds, burns, radiation damage, ingress of a foreign body, there may be narrowing and fusion of the tubules.

Examining the region of the lacrimal sac, attention is drawn to whether there is swelling under the medial ligament of the eyelids or ectasia of the lacrimal sac. Swelling over the ligament is more likely associated with damage to the border areas - the paranasal sinuses, and with a wide nose, it cannot be confused with a cerebral hernia. Next, you need to press your finger on the area of ​​​​the lacrimal sac. If a mucous, mucopurulent or purulent discharge appears from the lacrimal openings, this indicates the presence of dacryocystitis.

On examination, you can see some congenital changes in the lacrimal sac - these are fistulas.

Functional studies of the lacrimal ducts

The canalicular test characterizes the function of the lacrimal ducts. 1-2 drops of 3% collargol solution or 1% fluorescein solution are instilled into the conjunctival sac. The patient should make several blinking movements. Normally, the coloring matter quickly disappears from the conjunctival cavity.

nasal test

A lacrimal-nasal test is carried out according to West, which characterizes the functional state of the lacrimal ducts. 1-2 drops of a 1% solution of fluorescein or a 2% solution of collargol are instilled into the conjunctival sac, the patient's head is slightly tilted forward so that the colored tear does not go into the nasopharynx. Then, after 3-5 minutes, the patient is offered to blow his nose into a gauze napkin. If after 3-5 minutes a yellow color appears on the napkin, the test is considered positive (normal patency of the lacrimal ducts). If staining appears after 10-15 minutes, the test is delayed. If the napkin is not stained after 20 minutes, the test is negative. If the test is negative, the lacrimal ducts should be washed to establish the anatomical patency of the lacrimal ducts.

Washing is carried out - the introduction of fluid through the lacrimal opening with a syringe, through the lower or through the upper lacrimal canaliculus, after preliminary anesthesia. The patient is seated on a chair opposite the doctor, a kidney-shaped basin is given to his hands, which he holds under his chin. When the patient looks up, the doctor with the index finger of the left hand pulls the lower eyelid down outwards so that the lacrimal punctum is clearly visible. With the right hand, the lacrimal opening expands with a conical probe. First, they are introduced, holding the probe in a vertical position, and then transferred to a horizontal one along the length of the tubule. After dilation of the lacrimal opening, a blunt syringe cannula is inserted. The syringe is held like a pencil when writing. They press on the syringe plunger, and so that the liquid does not flow into the nasopharynx, the patient's head should be tilted forward, over the basin. If the liquid flows out in a plentiful stream from the corresponding half of the nose, then this is a free patency of the lacrimal ducts.

With increased pressure on the piston, part of the fluid flows out of the upper lacrimal opening and drops out of the nose - this is a narrowing in the vertical section. If the fluid flows only from the lower point, it is an obstruction, more often than the lacrimal canal, and if the fluid flows only from the upper lacrimal point, but with mucus or pus, this is dacryocystitis.

In case of obstruction of the lower tubule, washing is carried out through the upper lacrimal opening and the results are similarly evaluated (Cherkunov B.F., 2001).

Washing is contraindicated in case of phlegmon of the lacrimal sac.

In children, the washing procedure is fraught with difficulties. Instead of metal cannulas, thin elastic capillaries made of synthetic plastics 0.8 mm thick and 5-8 cm long are used. A thin rubber tube 16-20 cm long is put on the cannula at one end, and connected to the injection needle sleeve at the other. The cannula is inserted into the lacrimal canaliculus, and the rubber tube is fixed at the outer corner of the palpebral fissure on the cheek with an adhesive plaster.

For diagnostic and therapeutic purposes, probing of the lacrimal ducts is carried out.

When probing the lacrimal ducts, after instillation of a 0.5% solution of dicaine (or inocaine) and preliminary expansion of the lacrimal openings, a probe lubricated with a disinfectant ointment is inserted. The probe is first inserted 2-3 mm vertically to the plane of the intramarginal space, then transferred to a horizontal position by turning 90° and advanced very carefully.

With free patency of the tubule, it should sink 12-15 mm until it rests against a clearly palpable bone wall of the lacrimal fossa. The probe can rest against one of the folds of the tubule mucosa. It is necessary to bypass the fold, bringing the probe back and changing its direction (Cherkunov B.F., 2001).

If it is necessary to resort to probing the sac and the lacrimal canal, then for anesthesia, in addition to 2-3 times instillation of a 0.25-0.5% solution of dicaine (or inocaine), it is good to introduce a 2% solution of novocaine or a few drops into the lacrimal ducts dikain. When probing the left tear-nasal duct, the doctor should stand in front and somewhat to the left of the patient, the right - to the right, you can stand behind the patient. After advancing the probe until it stops against the bone wall of the lacrimal fossa, turn the probe into a vertical position and advance it along the inner wall of the lacrimal sac and the lacrimal-nasal canal, which starts 10 mm down from the place of the initial stop against the bone wall. The probe should be directed to the upper end of the nasolabial fold, then it enters the lacrimal-nasal canal and will slide down until it rests on the bottom of the lower nasal passage. Moreover, when the probe is inserted through the lower lacrimal canaliculus, the lower eyelid should be pulled down and outward with the thumb or index finger of the left hand, and when probing through the upper canaliculus, the eyelid should be twisted and pulled up and outward. After resting on the bone wall, the eyelid is released. Along the way, there may be strictures in any part of the vertical section, but more often when the lacrimal sac passes into the nasolacrimal canal and in the lower membranous part of the latter. Total obliteration of the sac and lacrimal canal is possible.

Can be probed from below, retrograde, endonasal. In order to have an idea of ​​the state of the lacrimal ducts along their entire course, X-rays are performed with contrast of the lacrimal ducts, using contrast agents that are iodized oil, preferably 30% yodipol.

Before the introduction of iodlipol, it is heated, the lacrimal ducts are pre-washed, and 1 ml of a contrast agent is injected through the lower lacrimal canaliculus with a syringe. The introduction is carried out very carefully, but with moderate pressure on the syringe plunger, since oily solutions are viscous. Excess contrast agent from the conjunctival cavity is carefully removed with a cotton swab, and the edges of the eyelids are also wiped. Radiographs of the lacrimal organs are carried out in 2 projections: occipito frontal and lateral. There are other methods as well.

Lacrimal sac massage

Massage is performed by several jerky or vibrating finger movements with some pressure directed from top to bottom. Before the massage, disinfectant drops are instilled into the conjunctival cavity, preferably from antibiotics. It is necessary to do massage 2-3 times a day, 2 times a week the doctor himself should massage. If there are signs of acute inflammation, massage should be immediately abandoned. After 7-10 days of unsuccessful massage, you should proceed to washing the lacrimal ducts, then probing is performed.

After examining the lacrimal organs, the conjunctiva of the eyelids, transitional folds and the eyeball are examined.

To examine the conjunctiva of the lower eyelid, the patient should look up. With the thumb placed 1 cm below the ciliary edge, the lower eyelid is pulled down. The conjunctiva of the lower fornix protrudes forward in the form of a roller, and the entire conjunctiva of the lower eyelid and the lower transitional fold are clearly visible. To examine the conjunctiva of the upper eyelid, the patient looks straight down. With the thumb of the left hand, placed at the upper cartilage, the skin of the eyelid is slightly pulled upward, thereby moving the edge of the upper eyelid away from the eyeball. With the thumb and forefinger of the right hand, they take the edge of the eyelid and pull it down and slightly forward. The captured eyelid is turned over around the thumb of the left hand, as if on a hinge. The everted eyelid is pressed against the upper orbital edge with the index finger of the left hand, and the conjunctival surface is facing the researcher.

When turning the eyelids in young children, it is more convenient to make a turn by placing a glass rod under the orbital edge instead of a finger.

To examine the upper transitional fold in both adults and children, the Demarra eyelid lifter is used. It is applied to the upper eyelid so that a wide saddle-shaped plate touches the eyelid at the upper edge of the cartilage, and the handle is directed downwards. The eyelid is taken by the ciliary edge and rotated around the plate of the eyelid lifter, and the handle of the eyelid lifter is lifted up. At the same time, the conjunctiva of the upper eyelid, the upper transitional fold and the conjunctiva of the upper half of the eyeball are visible. Normally, the conjunctiva is transparent and appears to be the same color as the tissue it covers. The conjunctiva of the upper eyelid has a pink color (the excretory ducts of the meibomian glands and a network of blood vessels lying in the submucosal tissue are clearly visible through it), more intense in the corners of the eye.

Conjunctiva the eyeball seems white due to the small number of vessels in it, it covers the white sclera. The surface of the conjunctiva is normally smooth, even, shiny, has a high tactile sensitivity, no discharge, films and scars. In inflammatory processes of the conjunctiva, its color, transparency and smoothness change. It becomes hyperemic, the vessels are dilated. Hyperemia of the conjunctiva of the cartilage and transitional folds extends to the conjunctiva of the eyeball. The scleral surface of the eye becomes hyperemic due to the abundance of blood vessels in it, which normally do not appear. Vessels in the form of trunks and loops are located superficially, injected. This is a conjunctival eyeball injection.

The conjunctiva swells, sometimes there may be a significant swelling of it, which is called chemosis. Chemosis can be in acute inflammatory diseases of the conjunctiva, purulent ulcers of the cornea, acute purulent inflammation inside the eyeball (iritis, choroiditis, panophthalmitis, endophthalmitis), inflammation of the periosteum of the orbit, Tenon's capsule, phlegmon of the orbit, with barley. Chemosis can be with local stagnation of blood and lymph, which occur with retrobulbar tumors, with aseptic foreign bodies in the orbit during their long stay, with thrombosis of the veins of the orbit, insect bites. Chemosis can be due to general diseases of the body, such as kidney disease, anemia, as well as menstrual disorders. It differs from chemosis in inflammatory diseases by color, transparency of the connective membrane, and the absence of hyperemia. There may be hemorrhages in the conjunctiva, more often in the conjunctiva of the eyeball. Hemorrhages occur with inflammation of the conjunctiva itself, with injuries, pressure of the chest, with constipation, vomiting, sneezing, lifting weights, with labor pains, with arteriosclerosis, diabetes, avitaminosis C, malaria, hemorrhagic fevers.

The color of the conjunctiva may change in Addison's disease, after the use of a preparation of silver, as well as topical application of silver in the form of eye drops.

Diffuse blanching of the conjunctiva is observed with anemia, after serious illnesses. In the conjunctiva, scars can be found that occur as a result of various diseases, such as diphtheria, gonorrhea, syphilis, tuberculosis, pemphigus, leprosy, foot and mouth disease, infected wounds, burns. Trachoma is an important cause of scarring.

In the conjunctiva, age spots (naevi) can be detected, more often in the conjunctiva of the sclera, melanoma.

A lot of people have yellow, slightly elevated formations of a triangular shape of the conjunctiva of the eyeball, located near the cornea inward and outward from it, these are the so-called pingvecula. This is the rebirth of the connective sheath in a place that has been irritated by dust, air, etc.

The smoothness of the surface of the conjunctiva violate the so-called follicles. The follicles are rounded formations of a yellowish-pink color, the size of a pinhead. They are enclosed in the thickness of the connective sheath, but protrude above its surface. The follicles of the conjunctiva of the eyelids are detected where the membranes are denser, between the follicles the connective tissue can be almost normal. Hyperemia and infiltration may be observed, and the conjunctiva may secrete a large amount of mucopurulent products. With trachoma, there are many follicles, they are densely located both in transitional folds and in the cartilage conjunctiva, the intermediate tissue is inflamed, often with scarring.

Under the influence of long-lasting purulent inflammation of the conjunctiva, so-called papillae develop, which give the conjunctiva a velvety appearance.

Somewhat follicular-like roughness is the main symptom of spring catarrh. With spring catarrh, these roughnesses are larger than follicles, hard to the touch, appear in spring and summer, often with the onset of a cold period or a change in climate, they disappear without a trace.

Of the elevations of a solitary nature, one should point out conflicts that occur on the conjunctiva of the sclera and are nodules the size of a pinhead to a hemp seed, located near the circumference of the cornea, after a few days of existence they either dissolve or ulcerate. Not to be confused with a pinguecula.

The smoothness of the conjunctiva can be disturbed by small tumors - nevus, papillomas, serous cysts. Similarities with such cysts in transparency and appearance are the expansion of the lymphatic vessels, which are mainly on the eyeball and are distinguished by an elongated, tortuous shape.

There may be depressions (defects) in the connective sheath as a result of ulceration and wounds. Ulcers can be due to pemphigus, herpes Zoster, after infected wounds, conflicts, soft chancre, hard chancre, resorbed gum, tuberculosis, glanders, epithelioma.

In the lower arch of the conjunctival sac and on the conjunctiva of the eyelids, one can see a mucopurulent discharge, which sticks together the eyelids in the morning. Normally, the goblet cells of the conjunctiva secrete a small amount of mucous secretion, which moisturizes and creates, as it were, a lubricating layer between the inner surface of the eyelids and the cornea. But it may be that the cells produce less secretion or completely stop producing it. There is xerosis of the mucous membrane. This may be due to both local and general causes. Local causes are changes in the tissue of the conjunctiva, as a result of which microscopic apparatuses that produce a mucous secret are destroyed, i.e., goblet cells in the epithelium, small glands in the submucosal tissue. This can be observed after such diseases as trachoma, pemphigus, foot and mouth disease, after various burns, eversion of the eyelids, with Stevens-Johnson syndrome, etc. But especially pronounced severe xerosis occurs after trachoma and pemphigus, in which the entire cornea also dries up and becomes cloudy totalis).

Of the common diseases, serious diseases should be noted, accompanied by a strong decline in nutrition, depletion of the body: cholera, typhoid, liver disease, starvation. With a disorder of the general metabolism, xerosis was also observed.

When examining the eyelids, the anterior, parotid, submandibular and cervical glands should also be examined in order to have an idea of ​​their condition. After all, the connective sheath serves as a gateway through which the infection enters the body. The anterior glands are examined in the following way: they lay the index finger in front of the tragus, under the zygomatic arch and carry out light circular movements. Normally, the anterior glands are not palpable. Their increase occurs only in pathology. If there is one, it is important to determine the size, consistency, soreness and painlessness, the condition of the skin. Swelling of the anterior glands is observed in acute conjunctivitis, especially gonococcal, diphtheria, conjunctival ulcers, styes, often located at the outer corner of the palpebral fissure. The classic swelling of the anterior gland occurs with mumps, as well as with Parino's conjunctivitis.

In diseases of the eyelids and conjunctiva, there may be an increase in the submandibular and cervical glands.

Examination of the cornea can be done by simple inspection in daylight. Already by a simple examination in daylight or sufficient artificial light, you can see the main changes in the cornea (size, specularity, transparency). The diameter of the cornea is about 10 mm in the vertical and 11.5 mm in the horizontal meridian. The reduction in the size of the cornea in most cases is congenital (microcornea) and is more often observed with a decrease in the size of the entire eyeball (microphthalmus). The reduction in the size of the clouded cornea occurs due to some serious disease and is often accompanied by its flattening (applanacio cornea). An increase in the size of the cornea can be with a transparent state of the cornea and with its opacities. In a transparent state, spherical corneal enlargement (keratoglobus, megalocornea) and cone-shaped (keratoconus) are most often congenital, but more often they are acquired. Keratoglobus often joins the general stretching of the eye (buphthalmus). The enlargement of the transparent cornea is due to the progressive stretching of the scar tissue that replaces the normal cornea, the sensitivity of the cornea can be determined by touching the hair on the cornea.

But the main simple way to study the cornea is the method of lateral illumination. The patient sits on a chair, a lamp (preferably with frosted glass) is placed on the table to the left of him at a distance of 40-50 cm in front of the patient at the level of his head. The doctor sits opposite the patient, his legs are to the left of the latter's legs. Then the doctor takes a magnifying glass 13.0 D or 20.0 D with his right hand, slightly turns the patient's head towards the light source and directs the light beam to the eyeball. The magnifying glass is placed between the light source and the patient's eye, taking into account its focal length (7-8 or 5-6 cm), so that the light passing through the glass is focused on the area of ​​​​the anterior eyeball to be examined.

When examining the cornea using the side illumination method, we can examine the main properties of the normal cornea: transparency, moisture, luster, specularity, smoothness. The transparency of the cornea is judged by the fact that the iris located behind it with its patterned pattern is so clearly visible. By moving the focus of the lens from site to site, it is determined whether there are any clouding or ingrowth of blood vessels into it, which the cornea does not normally contain. The loss of transparency leads to a decrease in the functions of vision. When cloudiness is detected, attention should be paid to its color (it is usually grayish, sometimes it is yellowish), size, shape, and borders of cloudiness. With keratomycosis, corneal infiltrates are in the form of geographical maps. There is only a slight defect of the epithelium - a satellite phenomenon. Fuzzy limitation of infiltrates. It is necessary to determine: turbidity is an old or fresh process.

If redness of the eyeball, pain, photophobia, lacrimation, blepharospasm are observed, then this is certainly a fresh process. In an acute process, we see a pericorneal injection of the eyeball, as well as a mixed one, i.e. pericorneal and conjunctival. The calm state of the eye indicates the completeness of the inflammatory process.

The result of inflammation or damage to the cornea is its clouding. It can be temporary and disappears as the reactive processes subside and reparative regeneration. But more often there is a persistent clouding of the cornea, which, depending on the localization, prevalence and severity of the inflammatory process, the severity of the damage, has a different shape, intensity and depth.

In the presence of a thin layer of altered tissue, a bluish-gray opacity is detected. A thick layer of altered tissue is usually white-gray or white. Opacity, located in the proper substance of the cornea, has an ash-gray color.

With persistent corneal opacities, changes in the anterior epithelium are always present. Histological examination of the cornea reveals areas of thinned epithelium with a decrease in the number of layers and flattening of cells and areas of thickened epithelium with an increase in the number of layers. Often, the cells of the anterior epithelium form deep outgrowths into the underlying tissue. The anterior border plate is usually destroyed, of uneven thickness, with uneven fuzzy contours, loosened. The structure of intercellular structures and cells of its own substance is disturbed: the corneal plates have an uneven thickness, are indistinctly contoured and defibrated. The posterior border plate and posterior epithelium also change.

The magnitude and intensity of turbidity are different. The infiltrate formed in the most superficial layers of the cornea completely resolves. The least pronounced, superficially located grayish opacity with blurred boundaries is called cloud-like opacity (nubecula). In this case, the morphological structures change insignificantly. Characterized by a somewhat irregular course of the corneal plates and undulating boundaries between the epithelium and its own substance.

Spot (macula)- this is a more saturated opacity of a grayish-white color with clear boundaries. In this case, the development of granulation tissue is observed. Sometimes the infiltrate and subsequent tissue breakdown capture most of the surface of the cornea, after which the process ends with the formation of an intensive extensive white scar - a leucoma.

There are complete and incomplete thorns. Incomplete thorns can have a central, peripheral or eccentric location. In the presence of walleye, the lamellar structure is replaced by scar tissue with more or less cellular elements.

In the case of perforation of the cornea, the anterior chamber fluid flows out, dragging the iris with it. In this case, the iris either fuses with the edges of the perforation, forming anterior synechia, or protrudes, followed by the formation of a walleye fused with the iris (leucoma cornea adhaerens). A flat leukoma soldered to the iris under the influence of intraocular pressure can stretch and bulge, forming a corneal staphyloma, which develops as a result of stretching of the scar. The thin protruding wall of staphyloma is easily accessible to various mechanical damage, which can open the gate for infection and lead to a serious illness. In cases where the iris is infringed in the perforation and prevents the development of a dense scar, a corneal fistula develops, which contributes to the penetration of infection into the eye and can lead to the development of endophthalmitis and panophthalmitis.

Corneal leukoma, fused with the iris, and especially with staphyloma, leads to a partial, and sometimes complete loss of vision and secondary glaucoma.

Corneal ulcer (ulcus cornea)- this is a serious eye disease that is difficult to treat and, as a rule, ends with visual impairment of varying intensity, up to blindness.

Ulceration of the central zone of the cornea is more severe, more difficult to treat, and its scarring leads to loss of vision.

The presence of blood vessels in the cornea always indicates its pathological condition. Vessels can be superficial, growing from the conjunctiva of the eyeball, and deep, growing from the episclera and sclera. The latter have the form of brushes, panicles. Superficial vascularization consists of branching vascular trunks, which pass from the conjunctiva through the limbus to the cornea.

In side illumination, a violation of sphericity can be seen. Normally, the cornea is spherical, without elevations and depressions. The slightest flaw on the smooth surface of the cornea is visible under side illumination. To determine the sphericity and smoothness of the cornea, the Placido keratoscope is used. It is a white disk with concentric black and white rings applied to it with a hole in the center. The patient is placed with his back to the window, a keratoscope is held in front of his eye, and the nature of the mirror image of the rings on the cornea is observed through the hole. In case of violation of the luster, sphericity of the cornea, the rings will be dull and irregular in shape.

The sensitivity of the cornea is determined using a wet swab folded into a very thin flagellum, which is touched to different parts of the cornea. With intact sensitivity, the touch of the flagellum causes a blinking reflex in the form of closing of the eyelids. For more subtle sensitivity studies, Frey's hairs, Radzikhovsky's algesimeter, etc. are used.

After examining the cornea, the anterior chamber is examined. It is known that the symptoms of pathological processes in the anterior chamber are reduced to a change in its two main properties: normal size and content. It can be examined by simple lateral illumination, better combined, and even better by biomicroscopy. The anterior chamber may be shallow in closed-angle glaucoma, in penetrating corneal wounds causing leakage of moisture, and in swelling cataracts. Under physiological conditions, a decrease in the depth of the anterior chamber is noted with farsightedness in the elderly, as well as in early childhood.

An increase in the depth of the anterior chamber occurs with aphakia, dislocation of the lens into the vitreous, with congenital glaucoma.

The anterior chamber in the presence of anterior synechia (synechia anterior), subluxations and dislocations of the lens may have an uneven depth.

An increase in the depth of the anterior chamber is noted with myopia. In addition to the depth and shape of the anterior chamber, changes in the moisture content of the anterior chamber can be determined using the side illumination method.

During pathological processes, the moisture becomes cloudy, normally it is transparent and colorless. With iridocyclitis and other processes, exudate appears. It can be serous, fibrinous, purulent and hemorrhagic. A weak degree of turbidity of the moisture of the anterior chamber is easily detected using a slit lamp. In this case, a pattern resembling the Tyndall effect is observed. Purulent exudate in the anterior chamber (hypopion) accumulates at the bottom. The amount of pus is different - a quarter, a third, half a chamber or more.

Hypopyon is a symptom of diseases that threaten the existence of the eye. Pus in the anterior chamber can be an exogenous infection with ulcers of the cornea after its perforation and with infected wounds. Before perforation, the pus in the anterior chamber is sterile. Endogenous infection penetrates through the blood, mainly from the vessels of the posterior part of the eye.

In the anterior chamber there may be blood (hyphema) in a very small amount only at the bottom of the chamber, it may reach the lower edge of the pupil or occupy the entire anterior chamber.

Hyphema often occurs with injuries, but it can be with general diseases (diabetes, hemorrhagic purpura), glaucoma, intraocular tumors, iridocyclitis, etc.

Lenticular masses may appear in the anterior chamber after injuries with damage to the lens, and the entire lens may fall into the chamber.

Sometimes there may be a foreign body in the chamber, which is introduced when injured. These are metal, wooden, glass and other bodies, as well as eyelashes, caterpillars, insect larvae.

Endogenously, a cysticercus can enter the anterior chamber, which is a dull gray bladder that moves freely in the chamber.

Trabeculae are superficially located vessels of the iris, shrouded in connective tissue, running radially. Between them there are recesses - crypts or gaps. Under side lighting, the crypts are dark in color, because through them shines through the pigment sheet lining the back surface of the iris. The alternation of trabeculae and crypts makes the surface of the iris embossed. The patterning is also due to the presence of a serrated line (projection of the pulmonary circulation of the iris), located concentrically to the pupil and dividing the iris into two zones: the inner pupillary and the outer ciliary, as well as the presence of the so-called "contraction furrows" running concentrically to the limbus in the ciliary region. In inflammatory diseases, the pattern of the iris fades as a result of soaking it with edematous fluid. Due to impregnation with a cloudy exudative fluid, in addition to the blurring of the pattern, the color of the iris changes.

Normally, the iris is light (blue and gray) and dark (light brown, dark brown, almost black). There are cases when one iris is light blue and the other is dark brown. This phenomenon is called iris heterochromia. When inflamed, blue and gray irises turn green.

When examining a normal iris using the side illumination method, one can see a pigment border at its pupillary edge - a part of the pigment sheet of the iris that extends beyond its front surface. It can be very wide, as if everted and pulled over the surface of the iris (a congenital anomaly, it should not be confused with a neoplasm). In older people with glaucoma, the pigment from the border disappears and it becomes gray.

In pathological cases, nodules of various sizes and colors can be seen in the iris (with tuberculosis, syphilis), sometimes cysts in the form of a translucent vesicle and tumors (melanosarcomas, leiomyomas or fibroids).

The lateral illumination method can be used to see iris defects - colobomas and iridodialysis. Colobomas can be congenital and acquired after surgical interventions. Congenital colobomas are always located along the lower inner meridian and can be partial and complete, while acquired colobomas are usually located from above. Iridodialysis - detachment of the iris at the root, it happens with injuries.

After the removal of the lens, the so-called iridodonesis is observed - a trembling of the iris, which is clearly visible during eye and head movements. One of the forms of the defect is the absence of the iris - aniridia (aniridia), which can be congenital or acquired. Acquired happens with injuries. You can see organic changes in the pupillary edge of the iris, which occur during inflammatory processes. This is the gluing, and then the fusion of the contacting surfaces - the anterior and posterior synechia. The anterior is the fusion of the iris with the cornea, the posterior is the fusion of the iris with the anterior lens capsule. They are clearly visible in side lighting, because. change the shape of the pupil. Synechia cannot be confused with the presence of a pupillary germinal membrane, which covers the entire pupil in embryonic life, but by the time the child is born, it resolves. In rare cases, individual sections of the film do not dissolve, but remain for life (membrana pupillaris perseverans) and, by the appearance of the remaining strands, resembles synechia.

In severe pathology or poorly treated diseases of the iris and ciliary body, the pupillary edge can be soldered to the lens throughout, forming a circular fusion - seclusio pupillae, and an exudative film can also be organized that covers the entire pupil area - occlusio pupillae. These changes lead to the development of secondary glaucoma. The fluid accumulating in the posterior chamber protrudes the iris, and along the periphery the iris almost touches the cornea (iris bombeae).

Since the main function of the iris is to regulate the amount of light rays entering the eye through the pupil, it is necessary to study the width of the pupil and its reaction.

The method of lateral illumination examines the location, diameter of the pupils, their shape, uniformity, reaction to light and close installation.

Normally, the pupil is located somewhat downward and medially from the center, the shape is round, the diameter is 2-4.5 mm. Pupil width should be the same in both eyes. With age, the pupil becomes narrower. Pupil constriction may be due to sphincter spasm or dilator paralysis. Spasmodic constriction of the pupil is caused by: local sphincter irritations (for example, inflammatory processes in the iris); the action of miotic agents (pilocarpine, ezerin); general intoxications (for poisoning with opium, morphine, nicotine); intracranial disorders (in the initial period of inflammation of the meninges and brain, with apoplexy, irritation of the nuclei of the oculomotor nerve, etc.); purely functional disorders of the nervous system (hysteria).

Paralytic constriction of the pupil

Local causes (dilator paralysis in the iris itself) do not play a big role. The main group of miosis is compression or damage to the cervical sympathetic nerve and its nodes: goiter, enlarged lymph glands, true tumors of the neck, wounds, tumors of the mediastinum, aortic aneurysms, etc.

Of the central causes - myelitis, syringomyelia, constriction of the pupil with dorsal tabes.

Mydriasis can be spastic and paralytic. Spasmodic pupil dilation is caused by:

Intraocular expansion of the dilator (cocaine instillation);

Extraocular irritations of the sympathetic nerve (goiter, swelling of the glands, tumors, aneurysm, etc.), which, with strong pressure, cause paralysis of the sympathetic nerve and paralytic miosis, and with weak pressure, irritation of this nerve - spastic mydriasis;

Irritation of the ciliospinal center (observed with meningitis, carbon dioxide poisoning);

Excitation of the brain in various cerebral convulsive diseases (epilepsy, etc.), apoplexy strokes, and psychoses;

Purely functional nervous disorders: hysteria (mydriasis is observed more often than miosis), neurasthenia, migraine.

Paralytic pupillary dilation is caused by:

1) intraocular paralysis (atropine), pupil dilation in glaucoma, trauma, loss of vision from intraocular diseases;

2) general poisoning: botulism (poisoning with meat poisons, mushrooms), alcohol, ingestion of drugs (belladonna);

3) central nervous diseases due to paralysis n. oculomotorii, together with paralysis of the direct external muscles or in the form of an isolated paralysis of the sphincter; sometimes together with damage to the external muscles of the eye due to damage to the nuclei n. oculomotorii.

Anisocoria - uneven pupils - is not a formidable sign of nervous diseases if the reaction of the pupils remains normal. Congenital unevenness is allowed. Uneven refraction in both eyes can cause unequal pupil size. Persistent irregularity of the pupils is observed as a result of a disorder in the paths of the sympathetic nerve after diseases of the pleura, lungs, kidneys, and liver.

Anisocoria can be with progressive paralysis, tabes dorsalis, brain tumors, hemorrhages, softening of the brain.

Of the reflex reactions of the pupil, the reaction of the pupil to light, as well as to accommodation and convergence, is of diagnostic importance.

Pupillary reaction to light

The patient looks into the distance, and we illuminate the pupil with a magnifying glass with bright light. The reaction to light appears very quickly. Direct reaction to light is established when the pupil of one eye is illuminated. By illuminating one eye, one can see that the pupil of the other eye is also contracting. This is a friendly reaction of the “second pupil” to light.

Response to convergence

The patient looks first into the distance, and then - at the tip of the finger, brought 10-12 cm in front of the patient's nose. There is convergence and simultaneous contraction of both pupils. This contraction is called the "accommodation response".

Pupillary response to eyelid closure

If, with the eyelids open, press them with your fingers to the upper orbital edge, and ask the patient to forcefully close his eyes, then you can notice the contraction of the pupils.

Response to pain

Under the influence of severe pain, dilated pupils are observed.

Mental reaction

With mental stress, the pupils dilate.

Pathological deviations of reflex reactions of pupils:

1. Loss of direct response to light while maintaining friendly and convergent.

When illuminating the diseased eye, the contraction of the pupil does not work; when lighting a healthy one, the pupils of both the healthy and the diseased eye contract.

The reaction to convergence is the same in both eyes.

This is due to a unilateral break in the light reflex path along its length from the eye to the sphincter nucleus, when one eye is blind from any damage to the retina or optic nerve.

In the case of bilateral blindness, depending on the interruption of the path to the nuclei, in both eyes there is a loss of both a direct and a friendly reaction to light, while maintaining a convergent one.

This combination is called cortical blindness due to organic diseases of the brain and functional blindness in hysteria.

2. Loss of direct and friendly reaction to light while maintaining convergent - under the influence of light, no reaction is obtained in both pupils, and the reaction to convergence occurs very quickly.

This happens with tabes (tabes of the spinal cord) and progressive paralysis of L (Argill-Robertson symptom).

With syphilis of the brain, this reaction is less common.

In some cases, this reaction can be with multiple sclerosis, syringomyelia, and other diseases (dementia, epilepsy, etc.).

3. Loss of all types of reaction ("absolute immobility of the pupils") occurs when:

A) instillation of mydriatics (atropine, midriacil);

B) nuclear paralysis (internal ophthalmoplegia, along with paralysis of the accommodative muscle: such paralysis of the pupil, especially in one eye, is often a sure sign of syphilis);

C) various infections (diphtheria, influenza) and poisoning (lead, meat, fish, oysters, etc.);

D) injuries and bruises of the eye, sometimes with tears of the sphincter, and sometimes without them.

There may be a myotonic reaction (complete lack of reaction to light, but a slow reaction to convergence), which is observed in some cases in progressive paralytics, in tabetics, alcoholics, diabetics.

Clinical (rhythmic) contraction and expansion of the pupil occurs in multiple sclerosis, chorea, epilepsy, cerebral syphilis, meningitis.

"Bouncing Pupils"- regardless of illumination and convergence, pupil dilation alternately appears on one or the other eye. It is observed with progressive paralysis, congenital paralysis of the oculomotor nerve, and some mental illnesses.

Paradoxical reaction- under the influence of light, the pupils dilate, and in the dark narrowing, rarely with tuberculosis and L-meningitis and other diseases on syphilitic soil.

The causes of pupillary symptoms can be divided into three groups:

1) local causes in the eye itself;

2) a general disease of the body;

3) disease of the nervous system.

From local causes- action of mydriatics and miotics; with inflammatory diseases of the eye - narrowing with iritis, expansion - with glaucoma; in diseases of the visual-nerve apparatus of the eye associated with a decrease or loss of vision - congestive discs, atrophy of the visual pathway, retinal diseases; with bruises - pupil dilation due to paralysis of the sphincter.

Of the common diseases (poisoning) - taking belladonna preparations (expansion), constriction in chronic morphinism (severe constriction with preservation of the reaction to light and convergence), pupil dilation in botulism (very often accommodation paralysis).

Post-diphtheria paralysis of the sphincter and accommodation: in diseases of the nervous system, pupillary symptoms are inconsistent and uncharacteristic of a particular disease.

With meningitis, constriction is observed first, and later dilation of the pupils; with syringomyelia - uneven pupils; with hysteria and neurasthenia - often expansion and unevenness; only pupillary symptoms represent regular phenomena - these are tabes dorsal is, paralytis progressiva, lues cerebri.

With dorsal dryness, all pupillary disorders occur.

With progressive paralysis - less often Robertson's symptom, then absolute immobility of the pupils.

With cerebral syphilis, the classic symptom is ophthalmoplegia interne and other types of pupillary disorders.

Cerebral syphilis is often localized in the area between the legs of the brain, where all parts of the reflex arc converge (centripetal and centrifugal pupillary pathways, nuclei of the internal muscles of the eye).

The course of the reflex pathways of the light reaction begins in the rods and cones, then the centripetal fibers go to the optic nerves, pass in the optic nerve to the chiasm, undergoing partial decussation in the chiasm, pass in the optic cord, go around the corpus geuiculatum externum, enter the substance of the anterior quadrigemina and reach the nuclei oculomotor nerve at the bottom of the aqueduct of Sylvius. In a special nucleus of the latter, intended for the sphincter of the pupil (receiving excitation from both eyes due to the decussation), the centrifugal path of the reflex arc begins. In the fibers of the oculomotor nerve, it reaches the ganglion ciliare in the orbit, from here, along the short ciliary nerves, after perforation of the sclera in the circumference of the optic nerve, it goes in the suprachoroidal space to the sphincter of the iris.

If there are separate opacities in the anterior layers of the lens, then under side illumination they are visible against the black background of the pupil in the form of separate grayish strokes, dots, teeth, etc.

With complete clouding of the lens, the background of the pupil has a dull gray color.

To determine the initial changes in the lens and vitreous body, the transmitted light method is used. The method is based on the ability of a pigmented fundus to reflect a beam of light directed at it. Research is carried out in a dark room. Matte electric lamp 60-100 watts should be on the left and behind the patient at the level of his eyes. The doctor at a distance of 20-30 cm from the patient with the help of an ophthalmoscope attached to his eye directs light into the eye of the patient.

If the lens and vitreous body are transparent, then the pupil glows red. The red light is partly due to the translucence of the blood of the choroid and the reddish-brown tint of the retinal pigment.

The patient is offered to change the direction of the gaze and monitor whether a uniform red reflex is observed from the fundus of the eye. Even slight opacities in the transparent media of the eye delay the rays reflected from the fundus, as a result of which dark areas appear on the red background of the pupil, corresponding to the location of the opacification.

If a preliminary study under side illumination did not reveal any opacities in the anterior part of the eye, then the appearance of eclipses against the red background of the pupil should be explained by opacification of the vitreous body or deep layers of the lens.

Opacities of the lens have the form of thin dark spokes directed towards the center from the equator of the lens, or individual points, or star-like diverging from the center of the lens. If these dark dots and stripes move along with the movements of the eyeball, then the opacities are in the anterior layers of the lens, and if they lag behind this movement and seem to move in the opposite direction to the movement of the eyes, this opacification is in the posterior layers of the lens. Opacities located in the vitreous body, unlike lens opacities, have an irregular shape. They seem to be cobwebs, they can look like networks that fluctuate with the slightest movement of the eyes.

With intense clouding of the vitreous body, massive hemorrhages in it, as well as with total clouding of the lens, the pupil does not glow when examined in transmitted light. It is possible to more accurately establish the type, shape of the lens, the degree of its clouding using the biomicroscopy method. With the help of a slit lamp, we can well examine all types of congenital cataracts (anterior and posterior polar, zonular, central, fusiform, total, "blue" cataracts), as well as all progressive acquired cataracts - senile (all stages of development), toxic, traumatic, complicated (due to diseases of the eye and general diseases).

In addition, we can determine abnormal forms of the lens (anterior and posterior lenticonus, congenital coloboma), changes in the position of the lens (ectopia of the lens, dislocation into the vitreous body, dislocation into the anterior chamber, under the conjunctiva of the eyeball), absence of the lens, secondary cataract.

Ophthalmoscopy. After conducting an examination of the eye in transmitted light, and making sure that the media of the eye are transparent, they begin to study the fundus, i.e., ophthalmoscopy.

This method makes it possible to see the retina, its vessels, optic nerve and choroid and obtain important data for doctors of other specialties (neurologists, therapists, neurosurgeons, endocrinologists).

After all, it is known that the retina and optic nerve embryologically represent a continuation of the brain. Genetic affinity implies the identity of the pathology, therefore, many diseases of the central nervous system affect either the direct spread to the visual-nerve apparatus, or the reflection of side symptoms in it.

With reverse ophthalmoscopy

The light source - a matte lamp 75-100 watts - is placed, as during the study in transmitted light, to the left and behind the patient.

The doctor sits opposite the patient. It is better to perform ophthalmoscopy after dilating the pupil with a 1% solution of homotropin or a 1% solution of mediacil. The doctor takes the ophthalmoscope (concave mirror) in his right hand and puts it to his right eye, directing a beam of light into the patient's eye to be examined, illuminating his pupil.

The doctor takes a biconvex lens with a power of 13.0 diopters in his left hand and, resting his little finger on the patient's forehead, holds it perpendicular to the beam of rays emerging from the eye at a distance of 7-8 cm from him. The fundus image appears between the loupe and the eye at or near the front focus. A true magnified and reverse air image of the fundus is obtained. In order to see the area of ​​the fundus under consideration, it is necessary to shift the gaze and try to fix the space somewhat in front of the lens, i.e. learn to accommodate to this place.

To see the optic disc of the right eye, the patient must look past the right ear of the doctor, and with the left - at the set aside little finger of the right hand holding the ophthalmoscope, or somewhat to the right of the right ear of the doctor. If we look with a magnifier with a power of 13.0 diopters, the magnification will be about five times, stronger magnifiers will give a stronger magnification, since the weaker the magnifier, the greater its focal length (the magnification is determined by the ratio of the focal length of the eye to the focal length of the magnifier). The focal length of the eye is approximately 15 mm.

The examination of the fundus in reverse usually begins with its brightest part - the optic nerve head, which is located approximately 15 ° downward from the macula, the patient's eye must turn by the same amount. To examine the area of ​​the macula, the subject must look directly into the mirror of the ophthalmoscope.

The periphery of the retina can be seen when the patient, at the request of the doctor, turns his eyes in different directions.

For a more detailed study of the fundus is used direct ophthalmoscopy. With it, a direct 14-16-fold enlarged image of the fundus is observed.

With the help of direct ophthalmoscopy, very small changes in limited areas of the fundus can be seen. Direct ophthalmoscopy is based on the laws of conjugate foci. To obtain a clear image of the fundus, it is necessary that the rays returning from the examined eye be parallel and, in turn, after refraction in the eye of the researcher, unite on the retina of the latter's eye. This is what we have with emmetropic refraction. Thus, the rays emanating from the focus of the eye of the researcher - the retina, after refraction in the media of the eye of the researcher and the researcher, are collected in the focus of the eye of the latter, on his retina. This is possible only if the refraction of the eye is emmetropic or the refractive error of the researcher is the same as that of the researcher, but the type of refraction is different. For example, if the researcher has a hyperopic refraction of +3.0 diopters, and the researcher has a myopic refraction of the same degree, of -3.0 diopters, or vice versa.

Direct ophthalmoscopy method: the pupil of the examined eye should be dilated, the doctor puts an electric ophthalmoscope to his eye and examines the fundus, holding the ophthalmoscope at a distance of 0.5-2 cm (no more than 4 cm) from the patient's eyes.

The right eye is examined with the right eye, and the left eye with the left. If the subject has a refractive error, it should be corrected using positive or negative lenses, which are on a rotating disk behind the ophthalmoscope mirror.

With direct ophthalmoscopy, the device must be held so that the index finger of the right hand lies on the disk, by turning which, if necessary, you can install a lens that corrects the doctor's refractive error. Having put the device to his eye, having received the reflex of the eye fundus of the researcher, the doctor approaches the eye of the researcher as close as possible until he sees the clearest image of the fundus. To examine various parts of the fundus, the device is rotated around a vertical or horizontal axis. Direct ophthalmoscopy is used in young children. When examining the fundus in direct form, a direct, imaginary and magnified image is obtained by 15-16 times.

You can examine the fundus in detail using a slit lamp and a fundus lens or a large non-reflex ophthalmoscope, which, thanks to the binocular attachment, gives a stereoscopic image. A reflexless ophthalmoscope is convenient for examining the fundus of the eye in older children. With direct ophthalmoscopy, we can also determine the difference in the level of the fundus, which is important in case of edema of the optic nerve head (congestive disc, edema neuritis), neoplasm, and so on, while the difference of 3.0 diopters corresponds to the actual difference in the level bottom in 1 mm. So, for example, if in an emetropic eye we find an area with a myopic refraction of -6.0 diopters, then this indicates a deepening of this area of ​​the fundus by 2 mm. If, however, in one of the areas of the fundus of the emmetropic eye, a hypermetropic refraction of +3.0 diopters is established, then this indicates that this area is protruding by 1 mm, etc.

In recent years, an electric Vodovozov ophthalmoscope has been used to study the fundus, the distinguishing feature of which is the presence of several light filters (red, yellow, green, purple), which makes it possible to more accurately identify the pathology of the fundus.

Normally, the optic disc is most often pale pink, round or oval, with clear boundaries.

The size of the disk is approximately 1.5 mm in diameter, but with ophthalmoscopy we see it significantly enlarged. With astigmatism, the disk appears not round, but elongated in the form of an oval. In the direct image, a longer disc diameter corresponds to a stronger refractive meridian, and a shorter diameter to a weaker one. With reverse ophthalmoscopy, the opposite is true.

The color of the disc is normally pale pink, it is composed of the brilliant grayish color of the fibers of the optic disc, the white color of the cribriform plate of the sclera and the red color of the vessels. The combination of these elements gives a pale pink color.

The temporal part of the ONH is normally paler than the nasal part, since there are fewer nerve fibers and vessels towards the macula than towards the nasal part.

In the very center of the optic disc there is a physiological excavation of a whitish color, where the vessels exit.

In pathology, the disc may be reddish in color (with optic neuritis) or pale, which occurs with partial atrophy of the optic nerve, or white with complete atrophy.

With glaucoma, the atrophic color has a gray-greenish tint. In very rare cases, the disc is black (as a consequence of traumatic hemorrhages or as a congenital phenomenon).

The borders of the disk are clear, and the temporal side seems to be more distinct in many than the nasal, because. towards the macula is a thinner layer of nerve fibers of the papillomacular bundle.

Blurring, ambiguity of boundaries is one of the obligatory signs of any inflammatory or edematous condition of the optic disc (neuritis, congestive disc). Blurred borders of the disc should be distinguished from the vagueness of the borders associated with changes in the adjacent parts of the fundus. These are inflammatory and atrophic changes in the choroid.

Uncertainty of disc margins occurs in the presence of Halo glaucomatosis. This is a yellowish rim, fairly evenly surrounding the entire disc.

The retinal vessels are represented by the central retinal artery and vein. They emerge from the center of the disc and, upon exit, are divided into two branches: nasal and temporal, which in turn are divided into upper and lower.

As a rare anatomical anomaly, a branch appears not from the central retinal artery, but from the posterior ciliary vessels (arteria s.vena cilio retinalis).

The arteries are somewhat paler and narrower than the veins (they are 2/3 of the width of the veins). The caliber of the vessels can change in the direction of narrowing or expanding. Narrowing is more characteristic of the arteries. The pathological color of the vessels themselves depends on two physical causes - changes in the composition of the blood and changes in the vascular walls.

There may be pulsation of the veins on the disc, but this is not considered a pathology.

A change in the vessels of the fundus is a change in the caliber, course of the vessels, color, change in the walls.

Yellow spot (macula lutea) located approximately 3.5-4 mm temporally from the edge of the optic disc and slightly below the horizontal meridian, has the appearance of a dark oval. Around the yellow spot in young people there is a shiny strip - a macular reflex, resulting from the reflection of light from the macular recess. In the center of the oval, a more red spot with a bright dot (foveolar reflex) is visible - this is the central fovea of ​​the macula (foveola centralis).

The yellow spot is devoid of blood vessels. They end before reaching the central fossa of the macula.

In children of the first year of life, the area of ​​the macula is fuzzy and its color is yellowish.

The macular region is supplied with blood from the superior and inferior temporal branches of the central retinal artery. Sometimes the cilioretinal artery coming from the posterior ciliary arteries also approaches it, and then the macular region has a dual blood supply. This is of great importance in case of circulatory disorders in the trunk of the central retinal artery.

The color of the fundus may vary depending on the amount of pigment. In blondes and young children, the fundus may be lighter in color, and choroidal vessels are often visible. In brunettes, the fundus appears darker.

The color of the fundus is made up of combinations of three colors: dark brown - from the retinal pigment, red - from the abundant amount of blood in the choroid, and white - from the translucence of the sclera.

The more pigment, the darker the general background of the fundus.

Diffuse discoloration (blanching) is observed with embolism, traumatic concussion.

Tonometry(measurement of intraocular pressure)

Intraocular pressure can be measured by the approximate method and by the tonometry method. For examination by the orienting method, the patient should look straight down, and the doctor, with index fingers placed above the level of the cartilage of the upper eyelid, alternately presses on the eyeball (similar to trying fluctuation) and gets an idea of ​​the degree of density of the eye, which is indicated by Tn (tension) - pressure is normal; T= +1 (moderately elevated); T \u003d +2 (significantly increased) and T \u003d +3 (dramatically increased). Hypotension is also indicated in a similar way, but with a negative sign: T \u003d -1; T=-2 and T=-3.

More accurately, intraocular pressure is measured using tonometers. The most common and accurate tonometer in our country is the Maklakov tonometer. The set consists of four cylindrical weights of various weights, equipped with end plates made of milky white porcelain.

The porcelain plate of a 10-gram tonometer is smeared with a thin layer of paint (preferably methylene blue 0.75 Bismarck Brown - 0.25, glycerin - 15 drops, water - 15 drops). Intraocular pressure is measured with the patient in a horizontal position.

A weight with a special holder is placed on the center of the cornea, previously anesthetized with a 0.5% solution of dicaine, inocaine or lidocaine. At the same time, the patient looks at the ceiling, at his finger of a raised hand, or at a special fixation point. The holder is lowered by 2/3 of the cylinder, so that the lowered weight flattens the cornea. After removing the tonometer from the eye, the imprint is transferred to paper pre-moistened with alcohol. Under the influence of the weight of the tonometer, the cornea flattens somewhat, and in the contact zone, the dye from the measuring platform passes to its surface. The latter leaves a colorless print of a rounded shape, which can be transferred to paper moistened with alcohol.

The diameter of the circle (imprint) is measured using the ruler of the Polyak B.L. meter, which makes it possible to immediately obtain the value of intraocular pressure in millimeters of mercury. The rest of the paint from the porcelain pads of the tonometer is washed off with a cotton swab moistened with alcohol or plain water.

Normal average numbers of intraocular pressure are 21 mm Hg. Art. with fluctuations from 16 to 26 mm.

Tonography

This method is used to study the hydrodynamics of the eye.

The tonometer is placed on the cornea in a strictly vertical position and kept on the cornea for 2-4 minutes. Due to compression, the outflow of fluid from the eye increases, and intraocular pressure gradually decreases. Changes in intraocular pressure during electronic tonography using a recording device are recorded on a moving paper tape. The degree of reduction in intraocular pressure during tonography depends on the amount of aqueous humor displaced from the eye, which in turn is associated with the state of the outflow tract. Using special tables, it is possible to determine the coefficient of ease of outflow, which characterizes the function of the drainage system of the eye, as well as the minute volume of fluid flowing from the eye.

The tonography method is especially valuable for the early diagnosis of glaucoma to control the effectiveness of medical and surgical treatment of glaucoma.

Normally, the coefficient of ease of outflow C \u003d an average of 0.25 mm³ / min per 1 mm Hg. Art.

Minute volume of aqueous humor F=1.9-4.0 mm³/min.

Becker coefficient, i.e., the ratio P 0 /c = not higher than 100. True intraocular pressure P 0 =20.5 mm Hg. Art.

The volume of the displaced fluid V=6.5-12.5 mm³.

Echoophthalmography

This method registers ultrasonic signals reflected from the interfaces between the media and tissues of the eye with different acoustic properties of the eye.

The echo-ophthalmography used for diagnostics in ophthalmology is characterized by simplicity, harmlessness and the possibility of repeated repetition if necessary to monitor the dynamics of the pathological process.

The studies are carried out on the apparatus echo-ophthalmograph (echo-21).

With the help of echography, it is possible to measure the anteroposterior size of the eye, the thickness of the cornea, the depth of the anterior chamber, the thickness of the lens, to detect detachment of the choroid and retina, tumors of the ciliary body, retina, choroid. With opaque optical media of the eye, it is possible to accurately determine the nature of the opacification of the vitreous body. It is also possible to identify clinically invisible foreign bodies and determine the depth of their location in the eye. Differentiation of the primary retinal detachment from the secondary one is determined by the growth of the neoplasm.

Electroretinography

In the diagnosis and differential diagnosis of retinal diseases, electrophysiological research methods are used.

Electroretinography is a method of recording the total bioelectrical activity of all retinal neurons.

It occurs when the retina is exposed to light stimuli of various sizes, shapes, wavelengths, intensity, duration, repetition rate under various conditions of light and dark adaptation.

Electroretinography allows you to determine both the initial biochemical disorders and gross atrophic and dystrophic processes, helps in differential diagnosis and monitoring the dynamics of the pathological process.

Indications for electrophysiological studies:

1. Differential diagnosis - hereditary retino- and choriodegeneration, Best's disease, congenital diseases of the optic nerve, congenital systemic diseases with eye lesions, siderosis, optic neuritis, albinism.

2. Finding out the cause of vision loss of unknown origin - unexplained vision loss, post-traumatic vision loss, unexplained complaints about vision in the dark, blindness.

3. Functional studies with clouding of the optical media of the eye - clouding of the cornea, before keratoplasty, mature cataract of unknown origin, clouding of the vitreous body.

4. Dynamic observation of eye diseases - differential diagnosis of the early stage of glaucoma, endocrine ophthalmopathy, compression of the optic nerve, in the treatment of atrophy with chloroquine, ethambutol poisoning, intoxication with tobacco, alcohol, vitamin A deficiency.

5. Detection of hereditary pathology - X-chromosomal abiotrophy, retinal abiotrophy (pigmented and non-pigmented).

Electrooculography (EOG) allows you to identify pathological changes in the pigment epithelium of the retina and photoreceptors. The Arden coefficient is calculated - the ratio of the potential of the light current to the potential of the dark decay, which normally does not exceed 185%.

Indications for EOG are: vitiliform maculopathy (Best's disease), carrier identification in Best's disease, therapeutic control when taking medications (phenothiazine, chloroquine), latent retinal degeneration (if ERG is not possible).

Arden coefficient = highest value of light peak X=100

The smallest dark drop value.

The norm is more than 180%

Probably normal 180-165%

Subnormal 165-130%

Pathological 130-110%

Very low< 110%

Inverted - EOG decreases with illumination

Visual evoked potentials (VEPs) are recorded to diagnose visual pathway lesions. VEP mainly reflect the electrical activity of the macular area, which is explained by its greater representation in comparison with the periphery in the spur groove. If it is impossible to register ERGs, then VEPs are the only source of information about the visual system.

Study of eye hemodynamics

The main methods are ophthalmodynamometry, ophthalmoplethysmography, ophthalmosphingmography, rheoophthalmography and Doppler ultrasound.

Ophthalmodynamometry (tonoscopy) allows you to examine the level of blood pressure in the central artery (CAS) and retinal vein (RCV). In age groups, the values ​​are different: normal pressure in the CAS up to 40 years is 70.2 \ 41.1; up to 60 years - 77.3\46.0; over 60 years old - 92.0\52.7 mm Hg. Art.

Ophthalmoplethysmography - allows you to determine the pulse volume of the eye.

Ophthalmosphygmography - allows you to register and measure IOP pulse fluctuations during a four-minute Grant tonography.

Rheoophthalmography - allows you to evaluate quantitative changes in the volumetric blood flow velocity in the tissues of the eye in terms of their resistance (impedance) to high-frequency alternating electric current.

Doppler ultrasound allows you to determine the linear velocity and direction of blood flow in the internal carotid and ophthalmic arteries.

Doppler ultrasound is used to determine the linear velocity and direction of blood flow in the internal and ophthalmic arteries.

Indications for ultrasound dopplerography:

1. Obstruction of the CAS and its branches.

2. Temporal arteritis (mandatory procedure before temporal biopsy).

3. Amaurosis due to embolism.

4. Unclear scotomas, ischemic lesions of the optic nerve.

5. Thrombosis of the CVS and its branches, unilateral cataract, iris atrophy.

Doppler ultrasound of the carotid arteries

Direct examinations of the common carotid artery, bifurcations, internal and external carotid arteries.

It is possible to speak about the reliability of altered Doppler signals, starting from about 50% vasoconstriction, 80% obliteration, which are diagnosed with a high degree of certainty.

For diagnosis, it is extremely important to compare the Doppler values ​​from the right and left sides.

If the clinical picture is pronounced, when it is necessary to identify Amaurosis fugax, and dopplerography does not give results, duplex scanning is indicated, and if necessary, angiography.

Fluorescein angiography of the retina

This method of studying the vessels of the retina is based on objective registration of the passage of a 5-10% solution of sodium salt of fluorescein through the bloodstream by serial photography.

This method is based on the ability of fluorescein to give a bright glow when irradiated with poly- or monochromatic light.

It can be carried out if the optical media are transparent.

Phases of fluorescein angiography. There are three phases of fluorescence

Filling phase

It starts 12-25 seconds after the injection with the filling of the choroid (t=a), then the retinal arterioles (t=0.5-2.5 seconds) and venules (maximum 10-15 seconds) are filled.

The recirculation phase is a slow dilution of the bomos dye with simultaneous distribution between tissues and vessels in the choroid (t = 3-5 min) and retention of fluorescein in the vessels of the retina. In this phase, violations of the barrier functions of the vessels and retinal membranes are most clearly manifested.

late phase

During the bleaching of the tissue (t= 10-30 min) the leakage is manifested by the prolongation of the fluorescence time.

With fluorescein angiography, one can see: the architectonics of the retinal vessels (vascular damage, anomalies, neoplasms); retinal vessel wall (extravasates); structures with a filtering effect, thickening, shade change, hypofluorescence; defects (hyperfluorescence), hemodynamics (blood flow delay, retrograde vascular filling).

This method is of great importance in the differential diagnosis of various diseases and injuries of the retina and optic nerve.

Questions:

1. What is the main method for the initial assessment of the condition of the eyelids?

2. What method determines the degree of protrusion (exophthalmos) or retraction (enophthalmos) of the eyeball?

3. What diagnosis should a general practitioner make in the presence of a conjunctival injection and abundant purulent discharge from the conjunctival cavity?

4. What structures of the eye can be examined using the transmitted light method?

5. What research methods are used to assess the condition of the cornea?

6. What method can determine the transparency of the lens and vitreous body?

7. What method can be used to examine the details of the fundus?

8. What methods are used to study IOP?

9. What method can be used to study the acuity of central vision?

10. What method can be used to examine peripheral vision?

11. For what diseases is the method of external examination sufficient for an approximate diagnosis?

12. What research method is needed for diseases of the cornea, changes in the contents of the anterior chamber, diseases of the anterior vascular tract, clouding of the lens?

13. What modern methods are used in case of suspicion of a neoplasm inside the eye?

14. In what diseases of the organ of vision are electrophysiological methods used to study the hemodynamics of the eye? Tear film break time

An eye examination should be part of any physical and premarket examination. The completeness of the examination will depend on the experience of the doctor and the availability of special equipment. While the information in this chapter is intended to provide the practitioner with the knowledge required to adequately/completely evaluate the eye, some of the techniques described here may be available to a limited number of professionals with specialized training and/or equipment. In order to correctly diagnose eye pathologies, it is necessary to know the normal anatomy of the eye. Therefore, general ideas about the normal anatomy of the equine eye and normal anatomical variations are also presented here. Since there are significant differences in the normal structure of the horse's eye, it may take years of practice before the researcher can confidently distinguish between normal and pathological variations. Comparison of a healthy and diseased eye in the same horse also contributes to a more correct understanding of the pathology and the norm.

OPHTHALMOLOGICAL EQUIPMENT AND RESEARCH TECHNOLOGY

Focus light source

Biomicroscope with slit lamp

Direct ophthalmoscopy

Indirect ophthalmoscopy

Local staining

FIXATION OF A HORSE FOR OPHTHALMOLOGICAL EXAMINATION

EYE EXAMINATION

Neuro-ophthalmological study

EXAMINATION OF THE ADDITARIUS EYE

RESEARCH OF THE DLAMIC DEVICE

CORNEAL EXAMINATION

FRONT CAMERA EXAMINATION

RESEARCH OF THE IRIS

LENS STUDY

REAR SECTOR RESEARCH

Anamnestic information about the child and the disease of his eyes is obtained mainly by interviewing parents, more often the mother, or the person caring for the child. Information received from the sick child himself is rarely taken into account, since children do not always know how to correctly assess their painful sensations, they are easily suggestible, and sometimes they can deliberately mislead the doctor.

First of all, it is necessary to find out what prompted the parents to see a doctor, when the first signs of a visual disorder or eye disease in a child were noticed, what they manifested themselves in, what their supposed cause was, whether there had been similar or any other eye diseases before, if any. whether their treatment was carried out, what kind, how effective it was. Based on the answers to these questions, the doctor makes a first impression of the child's eye disease and conducts a further survey in a more targeted manner. So, if the reason for going to the doctor was an eye injury in a child, then you need to find out the circumstances under which it occurred.

In cases of congenital or early acquired diseases eyes in a child, especially if their hereditary nature is suspected, a detailed family history may be required. The doctor must find out whether similar diseases were observed in the family before, in which generations and in whom, at what age these diseases began to develop.

If an infectious disease is suspected eyes, it is important to find out if there are similar diseases in the family, apartment or team in which the child is located. If one gets the impression that there is a connection between visual impairment in a child and visual work, then it is necessary to obtain information about its nature, duration, hygienic conditions, and the three sensations that arise.

Taking anamnesis from an adult patient

When taking an anamnesis in an adult patient, it is also necessary to be careful, because. patients often tend to withhold "irrelevant", in their opinion, information.

• Persistent visual impairment
• Most of the problems are related to the lack of clarity of vision.In principle, almost every person needs glasses in order to achieve the best vision, and ophthalmologists spend half their working hours selecting the appropriate vision correction.
• A cataract, or clouding of the lens, causes visual impairment in half of people over 50 years of age.
• Today, more than 230 million people on the planet suffer from diabetes, which is approximately 6% of the adult population of the globe.Diabetic retinopathy occurs in 90% of diabetic patients.
• AMD leads to loss of central vision and is the leading cause of blindness in people over 60 years of age.
• Glaucoma is a disease associated with increased intraocular pressure (IOP), which leads to damage to the optic nerve. Initially, there is a loss of peripheral vision; often the disease is almost asymptomatic.
• Temporary loss of vision for no more than half an hour with possible flashes of light
• After 45 years, a situation may arise when microembolism from arteriosclerotic plaques, when passing through the vessels of the eye or the cerebral cortex responsible for vision, causes a temporary deterioration in visual perception. In younger people, this may be caused by migraine-induced arterial spasm.
• flying flies
• Almost every person from time to time can see moving spots caused by suspended particles in the vitreous. This phenomenon is physiological, although sometimes the cause may be microhemorrhage, retinal detachment, or other serious disorders.
• flashes of light
• These flashes can be caused by sharp vitreous pressure on the retina and an increase in IOP and are sometimes associated with the formation of perforated retinal tears or retinal detachment. Strokes of the visual center of the occipital cortex are usually ischemic and cause more systematic jagged luminous lines.
• Nyctalopia
• Nyctalopia usually indicates that it is time to change your glasses; it is also often associated with age and cataracts.
• Rarely, retinitis pigmentosa and vitamin A deficiency may be the cause.
• Diplopia
• Strabismus, which occurs in 4% of the population, is a condition in which both eyes do not look in the same direction; binocular diplopia disappears if one eye is closed.
• In people without strabismus, diplopia can be caused by hysteria (hysterical neurosis) or the presence in one eye of an opaque area that scatters the rays; when the other eye is closed, it does not disappear (monocular diplopia)
• Photophobia (photophobia)
• A fairly common condition in which tinted lenses are prescribed, but sometimes photophobia can be caused by inflammation of the eye or brain;internal reflection of light in the case of lightly pigmented or albino eyes;
• Itching
• In most cases, the cause is allergies or dry eye syndrome, which affects 30% of older people
• Headache
• Headaches caused by blurred vision or an imbalance in the eye muscles are aggravated by eye strain.
• High blood pressure is the cause of 80-90% of headaches. It grows with excitement, headaches are accompanied by pain in the neck and temples.
• 10% of the population suffers from migraine. People experience a severe, repetitive, pressing headache that is accompanied by nausea, blurred vision, and zigzag flashes of light. The patient needs rest, after which the pain usually disappears.
• Sinusitis causes a dull ache in the eye area, and also in places causes increased sensitivity over the sinus. May be accompanied by nasal congestion; in history there may be an allergy, stopped by decongestants.
• Giant cell arteritis, which develops in the elderly, can cause headaches, loss of vision, pain when chewing, arthritis, weight loss, weakness. The diagnosis is confirmed by an erythrocyte sedimentation rate above 40 mm/h. Large doses of steroids must be used immediately, otherwise blindness or death may occur.

It is also necessary to ask the patient about the presence of common diseases, such as diabetes, thyroid disease, and about taking medications.

External examination

An external, or external, examination begins with an assessment of the type and condition of the patient's face, the location of his eyes and the auxiliary apparatus. To do this, the patient's face is well illuminated by a table lamp standing to the left and in front of him.

Examination of the organ of vision is carried out in a certain sequence, usually based on the principle of the anatomical location of its individual parts. Throughout the entire ophthalmological examination, a calm, abstract, entertaining conversation should be conducted with the child (about family, school, games, books, comrades, etc.).

Start the inspection with the definition position and movement of the eyelids . Changes in the skin of the eyelids (hyperemia, subcutaneous hemorrhages, edema, infiltration) and the edges of the eyelids (growth of eyelashes, scales and crusts at the base of the eyelashes, ulceration, cysts, nevi, etc.) should be canceled. Usually the eyelids are tightly adjacent to the eyeball, but as a result of various pathological processes, eversion or inversion of the eyelids can occur. Pay attention to the presence and nature of eyelash growth.

Lifting the upper eyelid and moving the lower eyelid down, determine the severity of the lacrimal openings, their position in relation to the lacrimal lake. By pressing on the area of ​​the lacrimal canaliculus or lacrimal sac, a possible discharge through the lacrimal openings of the pathological contents of the canaliculi and lacrimal sac is revealed. Raising the upper eyelid upward outward and inviting the child to look at the tip of his nose, they examine the palpebral part of the lacrimal gland.

Determine the completeness and density of the closure of the palpebral fissure. Then carry out examination of the conjunctival sac , primarily in order to identify a possible shortening of the vaults, tumors, etc. The examination is carried out by lifting the upper and pulling the lower eyelid. Consistently examine the conjunctiva of the eyelids, transitional fold, area of ​​the lacrimal sac and the eyeball. Normally, the conjunctiva of all its departments is smooth, shiny, moist, pale pink, sensitive to the gentle touch of a cotton wool or hair.

Next, determine condition of the eyeballs their size, shape and position in the orbit. There may be nystagmus, involuntary rhythmic movements of the eyeballs, an anterior displacement of the eye - exophthalmos or posterior - enophthalmos. The most common deviation of the eyeballs inside or outside - strabismus. Determine the amount of movement of the eyeball in all directions. During the examination of the eyeballs, special attention is paid to sclera color(it should be white or slightly bluish) and transparency, specularity, luster and moisture of the cornea, as well as the type and size of the limbus. The limbus usually has a smooth surface and a grayish color, its width is 1-1.5 mm, and with various types of pathology or congenital anomalies, the limbus has a different color (brownish, etc.) and large sizes, its surface is bumpy.

View with side lighting. Examination with side lighting is necessary for a more detailed study (the condition of the edge of the eyelids, allied points, mucous membrane (conjunctiva), sclera, limbus and cornea. In addition, it is important to determine the condition of the anterior chamber, iris and pupil. The study is best done in a darkened room. The lamp is placed to the left and in front of the subject, illuminating his face and the region of the eyeball.During the examination, the doctor directs a focused beam of light from the lamp to the rest of the eye using a lens (magnifying glass) with a power of 13.0 or 20.0 diopters, holding it in the right hand at a distance of 7-10 cm from the eye of the subject.

Mucous membrane of the lower eyelid and the vault is available for inspection when pulling the edge of the lower eyelid down, and the upper eyelid up, while the patient must look up or down. Pay attention to the color, surface (follicles, papillae, polypous growths), mobility, translucence of the ducts of the tarsal (meibomian) glands, the presence of swelling, infiltration, cicatricial changes, foreign bodies, films, discharge, etc. Detailed examination of the conjunctiva of the upper eyelid carried out after its eversion. To examine the mucous membrane of the upper fornix, which is invisible during normal eversion, it is necessary, with the everted eyelid, to lightly press through the lower eyelid on the eyeball.

looking around mucous membrane of the eyeball, pay attention to the state of its vessels, moisture, luster, transparency, mobility, the presence of edema, neoplasms, cicatricial changes, pigmentation, etc. White or bluish sclera usually shines through the normal mucous membrane.

• it can be dilated (for glaucoma),
• thickened
• infiltrated (with trachoma, spring catarrh),
• vessels from the conjunctiva can enter the limbus (with trachoma, scrofula, etc.).

With the help of focal illumination, it is especially necessary to determine transparency, (specularity, luster, shape and size (of the cornea), as they can change dramatically during inflammation (keratitis), dystrophies, injuries and tumors. With side illumination, the condition of the anterior chamber can also be assessed ( depth, uniformity, transparency), iris (color, pattern, vessels) and pupil (reaction, contours, size, color).

Examination of the eyes in young children with a sharp blepharospasm is possible only with the opening of the palpebral fissure with the help of eyelid lifters. The nurse, having put the child on her knees, holds his body and arms with one hand, the head with the other, and clamps the child's legs between her knees. The eyelid lifter is inserted under the upper and lower eyelids.

Inspection by the combined method . Inspection by the combined method is necessary to detect more subtle changes in the edges of the eyelids, lacrimal openings, limbus, cornea, anterior chamber, iris, lens and pupil. The method consists in lateral illumination of the eye and examination of the illuminated place through a manual or binocular loupe.

The combined method makes it possible to detect subtle changes in the shape, transparency, specularity and moisture of the cornea, to determine the duration of the existence of inflammatory infiltrates, their shape, depth of location, areas of ulceration, ingrowth of vessels into the limbus and cornea. Using this method, precipitates on the posterior surface of the cornea, turbidity of the moisture of the anterior chamber, newly formed vessels, atrophic and other changes in the iris and its pupillary belt, as well as clouding in the lens, its dislocation and even absence can be detected.

Examination of the reaction of pupils to light. Distinguish direct and friendly reaction of pupils to light. The direct reaction is determined by alternately illuminating the pupil area of ​​one or the other eye with any light source. Determining the activity of the pupillary reaction is best done in a darkened room. The easiest way to determine the direct reaction of the pupils to light is to cover the right and left eyes with the palm for a few seconds and quickly open them. Under the palm (in the dark), the pupil expands somewhat, and when opened, it quickly narrows.

The consensual reaction of the pupil of the right eye is determined with the illumination of the left eye and vice versa. More important for determining the presence of vision is the direct pupillary reaction. The presence of a reaction to light in each pupil separately indicates that the subject sees with both the right and left eyes. The liveliness (speed) of the pupillary reaction indirectly characterizes not only the presence, but also the quality of vision. Determining the reactions of pupils to light is important for the diagnosis of posterior adhesions of the iris in uveitis, its damage during contusion, etc.

Pupillary reactions can be examined and recorded using special devices - pupillographs. Such studies are most often carried out in neurological, neurosurgical and psychiatric clinics for topical diagnosis of pathology, assessment of the dynamics of the process and the effectiveness of treatment.

biomicroscopy

Biomicroscopic examination of the eye is carried out using a slit lamp, which is a combination of a binocular microscope with an illuminator. It illuminates the examined part of the eye with a slit beam of light, which makes it possible to obtain an optical section of the cornea, lens and vitreous body. Both vertical and horizontal slots of various thicknesses (0.06-8 mm) and lengths can be obtained.

Using a slit lamp, biomicroophthalmoscopy can be performed by introducing a diffusing lens with an optical power of 60 diopters, which neutralizes the optical system of the eye.

In biomicroscopy of the eye, various types of illumination are used: diffuse, direct focal, indirect (study in a dark field), variable (combination of direct focal with indirect); the study is also carried out in transmitted light and by the mirror field method.

Infrared meeting allows you to examine the anterior chamber, iris and pupillary area in cloudy corneas. The slit lamp can be supplemented with an appalanation tonometer, which can be used to measure true and tonometric intraocular pressure.

Biomicroscopic examination in young children (up to 2-3 years old), as well as restless older children, is carried out in a state of deep physiological or narcotic sleep, therefore, in a horizontal position of the child. In this case, it is impossible to use conventional slit lamps, which allow the study to be carried out only in the vertical position of the patient. In these cases, one can use Skepens electric forehead ophthalmoscope, which allows binocular stereoscopic ophthalmoscopy in reverse.

With biomicroscopy, the eyes follow a certain sequence. Conjunctival examination is important for the diagnosis of its inflammatory or dystrophic conditions. The slit lamp allows you to examine the epithelium, posterior border plate, endothelium and stroma of the cornea, judge the thickness of the cornea, the presence of edema, inflammatory post-traumatic and dystrophic changes, as well as the depth of the lesion, and distinguish between superficial and deep vascularization. Biomicroscopy makes it possible to examine the smallest deposits on the posterior surface of the cornea, to study in detail the nature of the precipitates. In the presence of post-traumatic scars, their condition is examined in detail (size, intensity, adhesions with surrounding tissues).

The slit lamp can measure depth anterior chamber , identify mild opacities of aqueous humor (Tyndall phenomenon), determine the presence of blood, exudate, pus in it, examine the iris, establish the extent and nature of its inflammatory, dystrophic and post-traumatic changes.

Biomicroscopy of the lens it is advisable to carry out under diffuse and direct focal illumination in transmitted light and in a specular field with the pupil maximally expanded by mydriatic means. Biomicroscopy allows you to establish the position of the lens, to judge its thickness, revealing spherophakia or the phenomenon of partial resorption of the lens. The method makes it possible to diagnose changes in curvature (lenticonus, lentiglobus, spherophakia), colobomas, lens opacities, determine their size, intensity and localization, as well as examine the anterior and posterior capsules.

Examination of the vitreous body carried out with the maximum dilated pupil, using direct focal illumination or a study in a dark field. A diverging lens is used to examine the posterior third of the vitreous body. Biomicroscopic examination of the vitreous body allows to detect and examine in detail changes in its structure in various pathological processes of a dystrophic, inflammatory and traumatic nature (opacities, hemorrhages).

Transmitted light research

A study in transmitted light is necessary to assess the condition of the deeper parts (structures) of the eye - the lens and the vitreous body, as well as for an approximate judgment about the state of the fundus. The light source (matte electric lamp 60-100 W) is located on the left and behind the patient. The doctor, using an ophthalmoscopic mirror, which he places in front of his eye, directs beams of light into the patient's pupil area.

Through the opening of the ophthalmoscope, with the transparency of the media of the eye, a uniform red glow of the pupil is visible. If there are opacities in the path of the light beam, they are defined as dark spots of various shapes and sizes against the background of a red pupil. The depth of opacities is determined by moving the patient's gaze. Opacities located in the anterior layers of the lens are shifted in the direction of eye movement, located in the posterior sections, in the opposite direction.

Ophthalmoscopy can be either direct or reverse. Reverse ophthalmoscopy carried out in a darkened room with the help of an ophthalmoscopic mirror and a magnifying glass with a power of 13.0 diopters, which is placed in front of the patient's eye at a distance of 7-8 cm. 7 cm anterior to the loupe. In order to examine a large area of ​​the fundus, if there are no contraindications, the pupil of the subject is pre-expanded. With reverse ophthalmoscopy, the optic disc (borders, color), the macular region, the central fossa, retinal vessels, and the periphery of the fundus are sequentially examined.

Direct ophthalmoscopy carried out for a detailed and thorough study of changes in the fundus. For its implementation, various hand-held electric ophthalmoscopes are used, giving an increase of 13-15 times. The study is convenient to conduct with a dilated pupil.

Ophthalmochromoscopy according to Vodovozov has the important feature that with its help it is possible to detect changes in various parts of the fundus that are not detected during direct and reverse ophthalmoscopy. This is achieved by introducing several light filters (red, yellow, green, magenta) into the electric ophthalmoscope system. The rules for using various light filters are detailed in the instructions for the ophthalmoscope, as well as in the atlas of ophthalmochromoscopy.

Gonioscopy

Gonioscopy is a study of the iridocorneal angle (angle of the anterior chamber) using lenses for gonioscopy and a slit lamp, due to the fact that the mirrors in them are located at different angles to the axis of the eye, it is possible to examine the iridocorneal angle, the ciliary body and the peripheral parts of the retina.

Before the study, epibulbar anesthesia of the patient's eye is performed (three times inlet into the conjunctival sac of 0.5% dicaine solution). The patient is seated behind a slit lamp and his head is fixed on a stand. Having opened the palpebral fissure of the examined eye, the lens is placed on the patient's cornea. The lens is held with the thumb and forefinger of the left hand, the illuminator and the slit lamp microscope are controlled with the right hand, focusing.

First, the iridocorneal angle is examined in diffuse light. In order to conduct its detailed study, focal slit illumination and 18-20-fold magnification are used. At the end of the study, in order to remove the lens, the patient is asked to look down and cover his eyes, this will avoid discomfort due to the "sticking" of the lens to the eye.

In young children (up to 3 years old, and often older ones), due to their restless behavior, gonioscopy is associated with significant difficulties, so the study is carried out only under anesthesia.

Gonioscopy allows you to determine the shape of the iris-corneal angle (wide, medium-wide, narrow, closed), examine its identification zones, and also identify various pathological changes in the iris-corneal angle:

• the presence of mesodermal embryonic tissue,
• anterior attachment of the iris,
• lack of differentiation of zones in congenital glaucoma;
• narrowing or closing of the angle in secondary glaucoma of various origins;
• the presence of newly formed tissue in tumors of the iris and ciliary body, etc.

IOP study

Tonometry may be preceded by an approximate palpatory determination of intraocular pressure. In young children (up to 3 years old), the method is practically the only one possible for assessing ophthalmotonus on an outpatient basis.

Intraocular pressure is determined using special devices - tonometers. According to the shape of the deformation of the cornea in the area of ​​its contact with the surface of the tonometer, applanation and impression methods of tonometry are distinguished. With applanation tonometry, flattening of the cornea occurs, with impression tonometry, its rod (plunger) is pressed into the device.

In Russia, the Maklakov tonometer (applanation type) is most widely used. It is produced in the form of a set of tonometers of various weights (5.0; 7.5; 10.0; 15.0 g). To determine the true intraocular pressure and the coefficient of rigidity of the membranes of the eyeball, an applanation tonometer is used in the form of an attachment to a slit lamp. In pediatric ophthalmic practice, it is practically not used.

Tonometry in children under 3 years old, and in restless older children (4-5 years old) is carried out in a hospital under conditions of deep physiological sleep, under anesthesia or using sedation. The use of hypnotics, sedatives and analgesics does not have a significant effect on the level of ophthalmotonus, reducing it by no more than 2-3 mm.

Pneumotonometry (non-contact tonometry) is based on the following principle: the cornea is flattened with a jet of air and then, using a special optical sensor, the time during which the cornea returns to its original position is recorded. The device converts this value into millimeters of mercury.

The procedure takes a matter of seconds. It is carried out in automatic mode: the patient fixes his head in a special apparatus, looks at the luminous point, opening his eyes wide and holding his gaze. An intermittent air flow is supplied from the device (it is perceived as pops) - and almost immediately the computer gives the doctor the necessary numbers.

Elastotonometry - a method for determining the reaction of the membranes of the eye when measuring ophthalmotonus with tonometers of various masses.

Tonography - a method for studying changes in the level of aqueous humor with graphic recording of intraocular pressure. Allowing to detect violations of the outflow of intraocular fluid, the method is of great importance in the diagnosis and evaluation of the effectiveness of the treatment of glaucoma, including congenital glaucoma.

The essence of tonography is that, based on the results of prolonged tonometry, which is usually carried out for 4 minutes, the main indicators of eye hydrodynamics are calculated: the outflow ease factor (C) and the minute volume of aqueous humor (F). The outflow easiness coefficient shows how much intraocular fluid (in cubic millimeters) flows out of the eye per minute for each millimeter of mercury column of filtering pressure. The study is carried out using an electronic tonograph or simplified tonography methods are used.

Research technique using Nesterov's electronic tonograph. The study is carried out in the position of the patient lying on his back. After epibulbar anesthesia with 0.5% dicaine solution, a plastic ring is inserted behind the eyelids and a tonograph sensor is placed on the cornea. Changes in intraocular pressure are graphically recorded for 4 minutes.

According to the tonographic curve and the results of the preliminary calibration of the device using special tables, the true intraocular pressure (P 0), the average tonometric pressure (P t) and the volume of fluid displaced from the eye are determined. Then, according to special formulas, the outflow coefficient (C) and the minute volume of intraocular fluid (F) are calculated. The main indicators of hydrodynamics can be determined without making calculations, but using special tables.

Simplified tonography methods

1. The intraocular pressure is measured with a Maklakov tonometer weighing 10 g. After squeezing the eye for 3 minutes with a sclerocompressor weighing 15 g, ophthalmotonus is again measured. The deterioration of the outflow of intraocular fluid is judged by the level of post-compression intraocular pressure.
2. The intraocular pressure is measured twice with a Maklakov tonometer weighing 5 and 15 g. Then a tonometer weighing 15 g is placed on the cornea for 4 minutes, after which the ophthalmotonus is measured. According to the difference in the diameters of the flattening circles before and after compression, F is determined and calculated according to the table.
3. Simplified tonography method according to Grant: after epibulbar anesthesia, a Schiotz tonometer is placed on the center of the cornea and intraocular pressure is measured (P 1). Without removing the tonometer for 4 minutes, the ophthalmotonus is again measured (P 2). The hydrodynamic indicators and the coefficient are calculated according to the Friedenwald table.

Tonography in children under 3-5 years old is performed under anesthesia. When interpreting the results of tonography in children with congenital glaucoma, certain difficulties arise due to changes in the size and curvature of the cornea, as well as the possibility of some influence of anesthetics on hydrodynamic parameters. The most sensitive test for hydrophthalmos is the Becker index, which normally does not exceed 100.

Most anesthetics, including halothane, reduce intraocular pressure. The possibility of a slight decrease in the level of intraocular pressure should be taken into account when evaluating the data obtained in the study of ophthalmotonus under anesthesia. When evaluating the results of studies conducted in children, one must also take into account the state of the anterior segment of the eye: an increase or decrease in the cornea, its flattening can affect the ophthalmotonus. In addition, the results of tonometry must be compared with age norms. In children under the age of 3 years, especially in the first year of life, the normal level of ophthalmotonus is 1.5-2.0 mm higher compared to older children.

It should be borne in mind that in healthy children under 3 years of age, especially in the first year of life, the indicators of eye hydrodynamics differ from those in older children. In children of the first year of life, R o averages 18.08 mm Hg. Art., C - 0.49 mm 3 / min, F - 4.74 mm 3 / min. In adults, these figures are 15.0-17.0, respectively; 0.29-0.31; 2.0.

Keratometry

Keratometry is already used in the study of the organ of vision in a child in a maternity hospital. This is necessary for the early detection of congenital glaucoma. Keratometry, which can be performed by almost anyone, is based on measuring the horizontal size of the cornea using a ruler with millimeter divisions or a strip of paper from a checkered notebook. Substituting the ruler as close as possible, for example, to the right eye of the child, the doctor determines the division on the ruler, which corresponds to the temporal edge of the cornea, closing his right eye, and corresponding to the nasal edge - closing his left eye. The same should be done when a “cell strip” is brought to the eye (the width of each cell is 5 mm).

When performing keratometry, it is necessary to remember the age norms of the horizontal size of the cornea:

• in a newborn 9 mm,
• in a 5-year-old child 10 mm,
• in an adult about 11 mm.

So, if in a newborn it fits into two cells of a strip of paper and a small gap remains, then this is the norm, and if it goes beyond two cells, then pathology is possible. For a more accurate measurement of the diameter of the cornea, devices have been proposed - a keratometer, a photokeratometer.

It should be noted that when examining the cornea, it is important to determine not only its transparency, sensitivity, integrity and size, but also its sphericity. This study has become especially important in recent years due to the increasing spread of contact vision correction.

To determine the sphericity of the cornea is currently used

Penetrating eye injury with intraocular (HIIT) are among the most serious and severe conditions faced by an ophthalmologist. Diagnosis requires a detailed history taking and detailed examination. Radiation is often required to confirm the diagnosis. Once the diagnosis is confirmed, patient management depends on the location of the foreign body and associated ocular injury. When foreign bodies are located in the posterior segment of the eye, it is recommended to consult a vitreoretinal surgeon.

Every year in USA about 2.5 million eye injuries are registered. Although HIIT injuries represent a small percentage of this number, they often require a large amount of surgical intervention. Intraocular foreign bodies occur in 20-40% of penetrating eye injuries. In most cases (86-96%) there are metal HIT. Other foreign bodies are most commonly glass, plastic, and eyelashes. A tendency to the occurrence of injuries with HIT in young men, especially those working with metal, has been noted. In a recent study, it was found that out of 297 patients with intraocular foreign bodies, 98% were male and 80% of the cases occurred during metal processing.

Foreign bodies, penetrating the eye, are usually small in size, sharp edges and high speed. Such injuries especially often occur during metal processing, planing, grinding. Small sharp objects with high speed penetrate the eye with minimal damage to surrounding tissues. Often such small corneal or corneoscleral wounds can heal on their own.

Against, large foreign bodies, especially with blunt edges, to penetrate the eye must move at great speed, while causing its concussion and significant associated damage, which significantly worsens the prognosis for visual functions.

Examination for intraocular foreign bodies

Vital It is important that the clinician have a high degree of alertness in anticipating the possibility of intraocular foreign bodies, so careful history taking is an essential component in the diagnosis of intraocular foreign bodies. In doing so, several key questions should be asked:
1. When did the injury occur?
2. What is the mechanism of injury?
3. Were protective equipment on the eyes at the time of the incident?
4. In case of work-related injuries, it is important to find out with what material the work was performed (iron, glass, wood, etc.)?

Collected clinical history allows to suspect or exclude the presence of an intraocular foreign body, as well as to clarify the direction of further examination and the need for additional research. You should also collect a life history, including information about the use of drugs at the moment. When planning surgery, you should find out the time of the last meal, as well as obtain information about the implementation of tetanus prophylaxis.

First of all check visual acuity, which can vary from unchanged to no light perception. Although visual acuity is of little importance for the diagnosis of intraocular foreign bodies, this indicator is an important prognostic factor. Measurement of intraocular pressure is carried out with caution. There is often, but not always, relative hypotension in the affected eye.

Celebrate row signs, which are often combined with intraocular foreign bodies:
1. Subconjunctival hemorrhage;
2. Transillumination defect of the iris;
3. Hyphema;
4. Local clouding of the lens;
5. Injury to the sclera;

6. Wound of the cornea;
7. Damage to the anterior and/or posterior lens capsule;
8. Vitreous hemorrhage;
9. Intra- or subretinal hemorrhage;
10. Relative hypotension;

11. Deep anterior chamber compared to the other eye;
12. Visible foreign body;
13. Lower local corneal edema.

Of decisive importance are eye examination on a slit lamp and examination of the fundus in conditions of drug-induced mydriasis. An obvious defect in the sclera, cornea, iris, or lens capsule with visualization of a foreign body allows a confident diagnosis. However, scleral wounds are often obscured by subconjunctival hemorrhage, and examination of the posterior segment is often hampered by hemorrhages in the anterior or posterior segment of the eye, making examination of the eye for an entry wound extremely important. Moreover, one should always be aware of the possibility of introducing several foreign bodies. If a wound is suspected, a Seidel test should be performed.

Gonioscopy in some cases, it helps to reveal hidden foreign bodies from localizations in the lower part of the angle and is indicated in the presence of a stable penetrating wound of the cornea without damage to the anterior lens capsule or transillumination defects of the iris. Transillumination is used to detect defects in the iris and lens capsule and is first performed with a narrow pupil (to detect iris defects), and then - with a wide one (to detect defects in the lens capsule), if pupil dilation is acceptable.

At survey eyes with a suspected meningeal defect should use common sense and avoid excessive manipulation. Contact methods of research (applanation tonometry, gonioscopy) should be performed with caution and provided that the wound is small and the eye retains its shape, as is often the case with intraocular foreign bodies. With extensive damage to the eye wall or with obvious deformities of the eye, the use of contact methods of research is unacceptable until surgical stabilization of the eye. In such cases, a limited examination is performed and a protective coating is placed on the eye, then the necessary additional examination is carried out to confirm the diagnosis and proceed with surgical intervention.

If a injury mechanism Intraocular foreign bodies are suspected and examination results are inconclusive, diagnostic imaging is required to confirm or rule out such a diagnosis. Plain radiography, which was previously the main method for diagnosing intraocular foreign bodies, with the onset of the era of computed tomography (CT), is used only when other, more modern research methods are unavailable. Numerous studies have found an unacceptably high rate of false negatives, especially with non-metallic foreign bodies.

At present, the main methods for the localization of intraocular foreign bodies are computed tomography and ultrasound. CT remains the most commonly used imaging modality for detecting intraocular foreign bodies.

Although the usual CT remains an acceptable method for detecting HIT, in a number of works it is compared with spiral CT. Helical CT scans are significantly faster, with fewer artifacts, higher resolution, and less radiation exposure. If a small foreign body is suspected, a CT scan with thin sections (preferably 1 mm thick) should be performed.

In the hands of an experienced specialist ultrasound can be a very valuable research method for the detection and localization of intraocular foreign bodies. However, there are a number of difficulties here. False echoes may be regarded as a foreign body. Ultrasound can overestimate the size of a foreign body, therefore, ultrasound should not be used to determine its size. Ultrasound results are highly interpretive and should only be trusted when performed by a specialist with extensive experience in ocular ultrasonography.