Underdeveloped eye. Hypoplasia of the optic nerve in newborns

Hypoplasia optic nerve in children early age: diagnosis, clinical significance

THEM. Mosin, V.F. Smirnov, E.V. Yaroslavtseva, N.V. Slavinskaya, EL. Neudakhina, I.G. Balayan

Optic nerve hypoplasia in infants: diagnostics, clinical significance

I.M. Mosin, V.F. Smirnov, E.V. Yaroslavtseva, N.V. Slavinskaya, E.A. Neudakhina, I.G. Balayan

Russian medical Academy postgraduate education, Moscow;

Tushinskaya children's clinical Hospital, Moscow; Moscow Research Institute of Pediatrics and Pediatric Surgery

In 32 infants aged 2 weeks to 11 months with optic nerve hypoplasia and 40 healthy children, biometrics of the optic nerve head was performed using a manual digital fundus camera, as well as neurosonography and magnetic resonance imaging of the brain. More than 2/3 of infants with optic nerve hypoplasia have structural brain anomalies. In healthy children under the age of 1 year, the vertical and horizontal excavation diameters were 0.31+0.06 and 0.32+0.07 of the disc diameter, respectively, the ratio of the excavation and disc areas was 0.10+0.04, the ratio of the foveolar distance - disk to disk diameter - 2.38+0.26. In children with optic nerve hypoplasia, the ratio of the foveolar-disk distance to the disk diameter was 4.59+1.67 (¿><0,001). Измерение отношения расстояние фовеола - диск к диаметру диска - простой метод диагностики гипоплазии зрительного нерва; диагноз устанавливается, если данный коэффициент превышает 2,9. Чувствительность метода - 96,9%.

Key words: newborns, infants, optic nerve hypoplasia, optic nerve hypoplasia, large cup syndrome.

Biometry of the optic disk by means of a manual digital fundus chamber, as well as neurosonography and brain magnetic resonance imaging were performed in 32 babies aged 2 weeks to 11 months who had optic nerve hypoplasia and in 40 healthy infants. Brain structural anomalies were detected in more than two thirds of babies with optic nerve hypoplasia. In healthy babies under 1 year of age, the vertical and horizontal diameters of excavation were 0.31+0.06 WP and 0.32+0.07 WP, respectively; the excavation/disk area ratio was 0.10+0.04; the foveola-disk distance/disk diameter ratio was 2.38+0.26. In infants with optic nerve hypoplasia, the foveola-disk distance/disk diameter ratio was 4.59+1.67 (p<0,001). Measurement of the foveola-disk distance/disk diameter is a simple method for diagnosing optic nerve hypoplasia; the diagnosis is established if this ratio is greater than 2,9. The sensitivity of the method is 96,9%.

Key works: neonatal infants, babies of the first year of life, optic nerve hypoplasia, large cup syndrome.

In economically developed countries, optic nerve hypoplasia accounts for about 5% of the causes of low vision and blindness in children. In the last decade, the number of children with optic nerve hypoplasia has increased significantly due to the achievements of perinatal nursing of premature and mature infants with pathology of the central nervous system caused by perinatal hypoxic-ischemic and infectious lesions. Diagnosis in young children, as a rule, causes difficulties due to the impossibility of accurately assessing the parameters of the visual disc.

th nerve during ophthalmological examination of infants with restless behavior, and difficulties associated with the interpretation of the ophthalmoscopic picture in the first months of life. Meanwhile, the detection of optic nerve hypoplasia in the first days of a child's life allows you to quickly determine the optimal diagnostic strategy in children with multisystem pathology, preventing the development of irreversible complications or even death as a result of late diagnosis of endocrine or neurological disorders.

The introduction of modern digital technologies for visualizing the fundus into clinical practice increases the possibilities of ophthalmoscopic diagnosis in cases where the use of routine methods does not allow an effective assessment of the parameters of the structures of the posterior pole of the eye. Conducting rapid biometrics of the spectator disk

of the optic nerve using digital imaging methods during the examination of infants, taking into account the ophthalmoscopic features of the neonatal period, would reduce the likelihood of diagnostic errors in the verification of anomalies of the optic nerve. In this regard, the present study pursued the following objectives:

Using a manual digital fundus camera, study the ophthalmoscopic parameters of the optic nerve head in healthy children and infants with various forms of optic nerve hypoplasia;

To study the state of brain structures in patients with verified optic nerve hypoplasia using the methods of radiation diagnostics.

Characteristics of children and research methods

We analyzed the results of ophthalmoscopy in 40 healthy children aged 2 weeks to 11 months and in 32 children of the same age with optic nerve hypoplasia of various etiologies.

The diagnosis was established on the basis of a neuro-ophthalmological examination, including direct and reverse ophthalmoscopy, registration of an electroretinogram and visual evoked potentials according to the method described earlier. Perinatal history and examination data were taken into account (the course of pregnancy in the mother, the presence of neonatal jaundice, hypoglycemia, seizures, immune status disorders, etc.).

All children were photographed while awake using a Nidek NM-200 handheld digital camera. Subsequent image processing was performed using the supplied commercial NAVIS image analysis software (Nidek, version 2005). When analyzing the image of the optic nerve head, the following parameters were measured:

The ratio of the vertical and horizontal diameters of the excavation and the optic disc;

The ratio of the distance from the foveola to the edge of the optic disc to the diameter of the disc;

The ratio of excavation area to disc area.

These coefficients were chosen to solve the set diagnostic tasks because in the NAVIS software all disk sizes are measured in pixels. To measure the above parameters in the software, the contours of the optic nerve head and excavation were outlined with the cursor, highlighting them in white and blue, respectively. Add-

A straight line was carefully drawn from the center of the foveolar or foveal reflex to the temporal edge of the disc in the equatorial region (Fig. 1).

All children underwent neurosonography using a Volus-on-730 ultrasonic diagnostic device (USA) with standard sector and micro-convex probes with a scanning frequency of 5-7 MHz. Children with optic nerve hypoplasia underwent magnetic resonance imaging of the brain using a Signa tomograph (General Electric, USA) using 5-10 mm sections.

A control group of 40 healthy children was formed based on certain criteria: uncomplicated history, delivery on time, birth weight of 2900 g or more, Apgar score of at least 8 points, absence of ophthalmic and systemic pathology, as well as changes in neurosonography. The Excel program was used for statistical processing of the results.

RESULTS

In healthy children under the age of 1 year, when measuring the parameters of the optic nerve head, the following results were established:

Vertical excavation diameter - 0.31±0.06 of the disc diameter;

The horizontal diameter of the excavation is 0.32±0.07 of the disc diameter;

The ratio of the areas of excavation and disk - 0.10±0.04;

The ratio of the foveolar-disk distance to the disk diameter was 2.38±0.26.

Ophthalmoscopy in all children with optic nerve hypoplasia revealed a decrease in the optic disc of varying degrees, the absence of

Rice. 1. The fundus of a healthy infant at the age of 2 months.

Image processing of the optic disc in the NAVIS software. The contours of the disk and excavation are highlighted in white and black, respectively. The borders of the disc and scleral ring coincide. White horizontal line - segment of the foveolus - edge of the disk.

foveal reflexes. In a number of cases, there was a pronounced decoloration of the disc, a symptom of a “double ring” formed by two pigmented corollas located along the perimeters of the reduced disc and the normal scleral ring, corkscrew-like tortuosity of the vessels (Fig. 2). The vertical and horizontal diameters of the disc in children with optic nerve hypoplasia ranged from 0.41 to 0.88 and from 0.32 to 0.91 of the disc diameter compared to the vertical and horizontal diameters of the normal scleral ring detected on the photograph, averaging 0. 75±0.17 and 0.70±0.17 disc diameters, respectively (^<0,01).

In children with optic nerve hypoplasia, the ratio of the foveolar-disc distance to the disc diameter in all cases exceeded the age standard, varying from 2.89 to 9.31 (Fig. 3). On average, the ratio of the distance between the foveolus and the disc to the diameter of the disc in children with optic nerve hypoplasia in

in our study was 4.59±1.67, which significantly exceeded the parameters of the control group (^<0,01). Чувствительность описанного метода оценки диска зрительного нерва составила в нашем исследовании 96,9%.

Neurosonography and/or magnetic resonance imaging revealed pathological changes in the brain in 22 out of 32 children with optic nerve hypoplasia. In 17 of them, combined changes in the brain were observed. The disorders found included: hypo- or agenesis of the corpus callosum (in 12 children), agenesis of the septum pellucidum (in 7 children), periventricular leukomalacia (in 7 children), porencephalic or arachnoid cysts (in 3 children; Fig. 4), posterior ectopia pituitary gland (3), schizencephaly (3), gray matter heterotopia to white (2), hydranencephaly (1), Dandy-Walker syndrome (1), colpocephaly (1), holoprosencephaly (1; see Fig. Fig. 2, b, c).

Rice. Fig. 2. Fundus of the eye (a) and neurosonograms (b, c) of a one-month-old child with optic nerve hypoplasia and holoprosencephaly.

a - the optic disc is reduced in diameter to 0.55 of the disc diameter, decolorized. The vessels are corkscrew-shaped. Symptom of the "double ring" (explanation in the text).

b - neurosonogram (coronary scanning at the level of Monro's orifices and third ventricle): holoprosencephaly (semi-lobar form); the lateral ventricles are fused together in the anterior sections.

c - neurosonogram (coronary scanning through the posterior sections of the lateral ventricles): holoprosencephaly; partial separation of the visual hillocks among themselves; the substance of the brain is presented in the form of a cloak-like zone along the periphery of the lateral ventricles.

Rice. 3. Fundus of a patient with optic nerve hypoplasia.

Image processing of the optic disc in the NAVIS software. The contours of the disk and excavation are highlighted in white and black, respectively. The horizontal size of the disc is reduced to 0.73 of the disc diameter. Pigmented scleral ring of normal size. White horizontal line - segment of the foveolus - edge of the disc. The ratio of the foveolar distance - the edge of the disk to the diameter of the disk is 3.22.

An analysis of the anamnesis data showed that prolonged (more than 2 weeks) neonatal jaundice was observed in 5 out of 32 patients, hypoglycemia - in 4, neurological symptoms (paroxysms, spastic diplegia, muscular dystonia, etc.) - in 18. The listed disorders were noted only in children with optic nerve hypoplasia and structural changes in the brain, verified by neurosonography and/or magnetic resonance imaging.

DISCUSSION

The detection of optic nerve hypoplasia in children during the first months of life plays an important role in the early diagnosis of various systemic somatic and neuroendocrine diseases (neonatal cholestasis, de Morsier's septooptic dysplasia, periventricular leukomalacia, etc.). Detection of optic nerve hypoplasia is a key point in differential diagnosis in genetic counseling, for example, in the clinical verification of Patau, Aper, Meckel-Gruber syndromes, Zellweger's disease. Meanwhile, an adequate assessment of the parameters of the optic nerve head in young children can cause significant difficulties due to their restless behavior. It is even more difficult to determine the size of the optic nerve head in infants with nystagmus, which is often associated with various pathologies of the eyes and the central nervous system.

The optic disc in healthy newborns appears gray or pale, physiological cupping and foveolar reflex are absent, and the vessels have a rectilinear course. Optic disk excavation, the diameter of which does not exceed 0.3 of the disk diameter, is determined only in 7.5% of healthy infants under the age of 6 months who do not have abnormal neurosonography. M.V. Drozdova discovered excavation of the optic disc in 25% of newborns, and T.V. Birich and V.N. Peretitskaya - in 28%.

Rice. 4. Arachnoid cyst of the brain in a child with hemianoptic hypoplasia of the optic nerve.

Magnetic resonance imaging (T1 mode): axial (a) and coronal (b) sections. Giant arachnoid cyst of the left hemisphere causing displacement of the midline structures of the brain and involving optic radiation. The medial sections of the left occipital lobe in the projection of the striate cortex are preserved.

But the authors did not evaluate its diameter, did not analyze the pre- and perinatal status of the examined infants, and, unfortunately, were not able to assess the state of their brain, including the post-genicular visual pathways, using the methods of radiation diagnostics. Therefore, it cannot be ruled out that some of the newborns they examined had structural changes in the brain.

The method described above for measuring the ratio of the distance of the foveolus - disk to the diameter of the disk in digital photography of the fundus is a simple and reliable way to diagnose optic nerve hypoplasia, including its various subclinical forms - horizontal sectoral hypoplasia, hemianoptic hypoplasia. In healthy children, the ratio (coefficient) of the foveolar-disk distance to the disk diameter is 2.38+0.26. A coefficient exceeding 2.9 (standard + 2a) indicates optic nerve hypoplasia. Examination with a manual digital camera (for example, the Noek NM-200 apparatus), including image analysis in software, takes about 5 minutes and does not require anesthesia, which makes it possible to use the technique for examining children from the first days of life. The small dimensions of the manual fundus-camera make it possible to conduct research in children

even in intensive care units without removing them from the incubator.

To diagnose another form of optic nerve hypoplasia, the extended excavation syndrome (Fig. 5, a), often observed in infants with periventricular leukomalacia (Fig. 5, b), at least three parameters must be compared with the norm: the horizontal diameter of the excavation (in the norm for children under the age of 12 months is 0.32 + 0.07 of the disc diameter), the ratio of the areas of excavation and disc (the norm is 0.10 + 0.04) and the ratio of the distance of the foveolus - disc to the diameter of the disc (in healthy children - 2, 38+0.26). The latter coefficient must be taken into account because a significant increase in excavation can be observed in children with congenital enlargement of the optic disc (megapapilla) and colo-bom-like optic nerve dysplasia. If the coefficient is less than 1.86 (standard -2a), then it can be assumed that the child has megalopapilla. In the differential diagnosis of megalopapilla and extended excavation syndrome, it is necessary to take into account the coefficient of the ratio of excavation areas and the optic disc. In healthy children and patients with congenital enlargement of the optic disc (megalopapilla), this coefficient is 0.10 + 0.04. In patients with the syndrome

Rice. Fig. 5. Fundus (a) and neurosonogram (b) of a child with extended excavation syndrome (a clinical form of optic nerve hypoplasia) and periventricular leukomalacia.

a - the optic disc has a normal diameter. The excavation is increased to 0.78 of the disc diameter in the vertical direction, to 0.84 of the disc diameter in the horizontal direction. The foveolar reflex is absent.

b - neurosonogram (coronary section): multiple periventricular cysts, moderate expansion of the lateral ventricles at the level of the anterior horns.

expanded excavation, the horizontal diameter of the excavation increases to 0.611+0.026 of the disc diameter, and the coefficient of the ratio of the areas of excavation and optic disc - up to 0.35+0.123 (^<0,001) , что свидетельствует о значительном увеличении площади экскавации и уменьшении площади нейроретинального кольца. Это связано с частичной потерей аксонов зрительного нерва вследствие транссинаптической нейро-нальной дегенерации .

Knowledge of the normal parameters of the excavation of the optic disc in children of the first year of life is also important for the early diagnosis of congenital glaucoma. It is known that with glaucoma there is a progressive increase in the vertical size of excavation, while in children with extended excavation syndrome, its increase is determined mainly horizontally in the temporal direction.

In more than 2/3 of children with optic nerve hypoplasia, pathological changes in the brain were revealed using radiation diagnostic methods. This does not contradict the results of previously published neuroradiological studies, according to which agenesis of the corpus callosum and / or transparent septum occurs in 46-53% of patients with optic nerve hypoplasia, other brain malformations - in 12-45% of patients. It should be noted the high frequency of detection of cystic periventricular leukomalacia in the group of children examined by us with optic nerve hypoplasia - in 7 out of 32 patients. This indicates that perinatal hypoxic-ischemic lesions of the periventricular white matter of the brain significantly more often than previously thought lead to disruption of the normal development of the pregenicular visual pathways and the formation of optic nerve hypoplasia.

Identification of certain anomalies of the optic nerve in children with lesions of the central nervous system allows you to set the period of damage to the fetus. L. Jacobson et al. It is believed that with lesions of the periventricular white matter of the brain that developed before 28 weeks of gestation, patients develop "classical" hypoplasia of the optic nerve, manifested by a decrease in its diameter. If damage to the periventricular white matter of the brain occurs after 28 weeks of gestation, then children develop extended excavation syndrome. Meanwhile, E. McLoone et al. when analyzing the results of neurosonography and ophthalmoscopic changes in 109 children with hypoxic-ischemic lesions of the periventricular

the white matter of the brain, which developed in the period from 24 to 33 weeks of gestation, such a pattern was not found. In patients with hydranencephaly, both clinical variants of the optic nerve anomaly are often found - "classic" optic nerve hypoplasia and dilated cup syndrome. It is known that hydranencephaly can develop with intrauterine viral or toxoplasmosis infection of the fetus in the period from 9 to 28 weeks of pregnancy due to cerebral infarction as a result of occlusion of the supra-sphenoid sections of the internal carotid arteries. It is not uncommon for these anomalies to coexist in the same patient, with dilated cup syndrome occurring in one eye and "classic" optic nerve hypoplasia in the other. S. Schismer et al. histological studies have established that normally the growth of the optic nerve head and its more proximal parts by 20 weeks of gestation is completed only by 50%, and by 38-40 weeks of gestation - by 75%. Thus, relying only on the results of ophthalmoscopy, it is impossible to determine the moment of perinatal lesion, since the mechanisms that induce the development of various forms of optic nerve hypoplasia in lesions of the periventricular white matter of the brain remain unclear.

Given the high frequency of neuroradiological abnormalities in infants with optic nerve hypoplasia, it is advisable for ophthalmologists and neonatologists to prescribe neurosonography for all children with this eye anomaly. Children in whom optic nerve hypoplasia is combined with prolonged neonatal jaundice, hypoglycemia and/or convulsive paroxysms should undergo an ultrasound examination of the abdominal organs and kidneys, as well as magnetic resonance imaging to exclude pathology of the central nervous system, in particular hypoplasia of the pituitary gland.

Measurement of the ratio of the distance between the foveola and the disc to the diameter of the disc using a manual digital fundus camera is a simple and sensitive (96.9%) method for diagnosing various, including subclinical, forms of optic nerve hypoplasia (horizontal sectoral and hemianoptic forms of hypoplasia, syndrome extended excavation). In healthy children, the ratio of foveolar distance - disc to disc diameter is 2.38 + 0.26. If this coefficient exceeds 2.9 (norm +2o), then the patient has optic nerve hypoplasia.

More than 2/3 of infants with optic nerve hypoplasia have structural brain anomalies. Children with optic nerve hypoplasia, combined with neonatal jaundice, hypoglycemia, or neurological symptoms, are shown to undergo a comprehensive examination.

research using methods of radiation diagnostics (neurosonography and magnetic resonance imaging, ultrasound examination of the abdominal organs) for the early detection of somatic and neuroendocrine dysfunctions.

LITERATURE

1. Hornby S J., Xiao Y, Gilbert C.E. etal. Causes of childhood blindness in the People's Republic of China: results from 1131 blind school students in 18 provinces. Br J Ophthalmol 1999; 83: 8: 929-932.

2. Good W.V., Jan J.E., Burden S.K et al. Recent advances in cortical visual impairment. Dev Med Child Neurol 2001; 43:1:56-60.

3. Gronqvist S., Flodmark O., Tornqvist K. et al. Association beetween visual impairment and functional and morphological cerebral abnormalities in full-term children. Acta Ophthalmol Scand 2001; 79:2:140-146.

4. Birich T.V., Peretitskaya V.N. Changes in the fundus of the eye in newborns during normal and pathological childbirth. Minsk: Belarus 1975; 176.

5. Khukhrina L.P. Some data of the state of the organ of vision of newborns. Bulletin oftalmol 1968; 5:57-61.

6. Filchikova L.I., Mosin I.M., Kryukovskikh O.N. Visual evoked potentials in normal children and with optic nerve hypoplasia. Vestn ophthalmol 1994; 3:29-32.

7. McLoone E, O "Keefe M, Donoghue V. et. al. RetCam image analysis of optic disc morphology in premature infants and its relation to ischaemic brain injury. Br J Ophthalmol 2006; 90: 4: 465-471.

8. Yannuzzi L.A., Ober M.D., Slakter J.S. et al. Ophthalmic fundus imaging: today and beyond. Amer J Ophthalmol 2004; 137:3:511-524.

9. Mosin I.M., Moshetova L.K., Slavinskaya N.V. Ophthalmic symptoms in children with periventricular leukomalacia. Vestn ophthalmol 2005; 121:2:13-18.

10. I. M. Mosin, L. K. Moshetova, and O. Yu. Ophthalmic disorders in children with periventricular leukomalacia. Pediatrics 2005; 1:26-33.

11. Brodsky M.C. Periventricular leukomalatia: an intracranial cause of pseudoglaucomatous cupping. Arch Ophthalmol 2001; 119:4:626-627.

12. Fahnehjelm K.T., Fischler B., Jacobson L, Nemeth A. Optic nerve hypoplasia in cholestatic infants: a multiple case study. Acta Ophthalmol Scand 2003; 81:2:130-137.

13. Jacobson L., Hard A.L., Svensson E. et al. Optic disc morphology may reveal timing of insult in children with periventricular leucomalacia and/or periventricular haemorrhage. Br J Ophthalmol 2003; 87:12:1345-1349.

14. Siatkowski R.M., Sanchez J.C., Andrade R., Alvarez A. The clinical, neuroradiographic, and endocrinologic profile of patients with bilateral optic nerve hypoplasia. Ophthalmology 1997; 104:3:493-496.

15. Mosin I.M. Optic nerve excavation anomalies: clinical manifestations and differential diagnosis. Vestn ophthalmol 1999; 5:10-14.

16. Brodsky M.C., Glasier C.M. Optic nerve hypoplasia: clinical significance of associated central nervous system abnormalities on magnetic resonance imaging. Arch Opthalmol 1993; 111:1:66-74.

17. Hoyt W.F., Rios-Montenegro E.N., Behrens M.M., EckelhoffR.J. Homonymous hemioptic hypoplasia: fundoscopic features in standard and red-free illumination in three patients with congenital hemiplegia. Br J Ophthalmol 1972; 56:537-545.

18. Volkov V.V. Glaucoma at pseudonormal pressure. M: Medicine 2001; 352.

19. Kurysheva N.I. Glaucoma optic neuropathy. M: MEDpress-inform 2006; 136.

20. Häussler M., Schäfer W.-D, Neugebauer H. Multihandi-capped blind and partially sighted children in South Germany I: prevalence, impairments and ophthalmological findings. Dev Med Child Neurol 1996; 38:12:1068-1075.

21. Herman D.C., Bartley G.B., Bullock J.D. Ophthalmic findings of hydranencephaly. J Pediat Ophthalmol Strabismus 1988; 25:2:106-111.

22-11-2013, 01:27

Description

Pathogenesis. Until recently, it was believed that optic nerve hypoplasia develops as a result of impaired differentiation of retinal ganglion cells at the embryonic stage. 13-15 mm, which corresponds 4-6 week of gestation. However, this hypothesis did not explain the phenomenon of frequent combination of optic nerve hypoplasia with brain malformations and was not supported by some histological findings. In particular, in patients with optic nerve hypoplasia, amacrine and horizontal cells remain intact, having common precursors with ganglion cells.

Perhaps, in some cases, optic nerve hypoplasia is the result of the culmination of axonal regression during apoptosis in the period from 16 th by 31 -th week of gestation or the outcome of retrograde degeneration in encephaloclastic processes leading to: the formation of brain defects (porencephaly, hydranencephaly, etc.) and causing damage to the pregenicular visual pathways.

The frequent combination of cerebral hemispheric anomalies with optic nerve hypoplasia suggests that its development is due to a violation of the mechanisms of regulation of intrauterine migration - both neurons of the cerebral hemispheres and axons of retinal ganglion cells. Optic nerve hypoplasia may be associated with suprasellar tumors such as teratoma. It is likely that in the prenatal period, when certain sections of the optic pathway are compressed by a neoplasm, the process of normal development of the optic nerve is disrupted.

Etiology. Teratogenic effects can aggravate the course of normal processes occurring in the prenatal period, such as apoptosis, leading to the development of optic nerve hypoplasia. In experiments on mice and when examining children born to mothers from the “high” risk group, it was shown that the use of cocaine or alcohol during pregnancy leads to a significant increase in the incidence of optic nerve hypoplasia in the offspring.

Optic nerve hypoplasia is found in 50 % newborns with fetal alcohol syndrome. As risk factors, the young age of mothers, the presence of insulin-dependent diabetes mellitus, smoking and the use of certain pharmaceuticals (phenobarbital, LSD, quinine, depakine, antidepressants) during pregnancy, prematurity are distinguished as risk factors.

Cases of the development of optic nerve hypoplasia in children with intrauterine herpetic or cytomegalovirus infection are described. No regular chromosomal defects were found in patients with isolated optic nerve hypoplasia. Meanwhile, Y.Hackenbrach et al. (1975) reported on 5 patients with bilateral optic nerve hypoplasia from different generations of the same family, suggesting an autosomal dominant mode of inheritance. A.J.Churchill et al. (2000) found a PAX6 gene mutation in 11p13 in a father and son with eye changes including aniridia, early acquired cataracts, and optic nerve hypoplasia. Mutation of the PAX6 gene at the 11p13 locus leads to the development of aniridia. It is important to note that the son's genetic defect was verified prenatally - during amniocentesis on 16 -th week of gestation.

Histological studies. Morphological studies of eyes with optic nerve hypoplasia revealed a decrease in the number of retinal ganglion cells. Horizontal and amacrine cells appear normal and do not decrease in number. The area surrounding the reduced optic nerve head is covered with retinal pigment epithelium, which creates an ophthalmoscopic "double ring" effect. In a histological study of hypoplastic optic nerves of fetuses extracted from rats that were on a diet containing 5 % alcohol, a significant decrease in the cross section of the affected nerve was found.

Electron microscopy revealed changes in the neuropil, a decrease in the number of astroblasts and the presence of pycnotic nuclei in some of them, atrophy and degeneration of the optic nerve axons, ultrastructural disorders of the myelin sheaths, astrocytes and oligodendrocytes. There were signs of extraoral edema in the layers of the retina (outer nuclear, nerve fibers and ganglion cells), a decrease in the number and size of axons, axonal and periaxonal edema (between the axolemma and the nerve sheath), thinning of myelin. K.Sawada et al. (2002) found selective loss of small-diameter myelinated axons in rabbits born to females treated with ethanol during pregnancy from day 10 to 21 of gestation.

Clinical manifestations. The first clinical description of optic nerve hypoplasia belongs to W. Newman (1864). Optic nerve hypoplasia varies in severity and can be either unilateral or bilateral. In infants with severe forms of the disease, parents notice strabismus, nystagmus, and a lack of adequate visual orientation in the child at an age 2-3 MSS. Nystagmus and/or strabismus is determined in 86- 92 % children with optic nerve hypoplasia. With a unilateral or asymmetric lesion, deviation of the eye is noted with more pronounced changes in the disc. It is not uncommon for patients with optic nerve hypoplasia to have an afferent pupillary defect.

Ophthalmoscopic manifestations of optic nerve hypoplasia:

Damage to the optic nerve can be isolated, but more often it is combined with ametropia (myopia, myopic or hyperopic astigmatism) and other eye anomalies (microphthalmos, congenital cataract, aniridia, primary persistent hyperplastic vitreous body, etc.).

Hypoplasia of the optic nerve in systemic lesions. Brain malformations are found in 50 % children with optic nerve hypoplasia. Cases of a combination of optic nerve hypoplasia with hemispheric migration anomalies (schizencephaly or cortical hegerotopias), as well as with intrauterine and/or perinachal lesions of hypoxic-ischemic, toxic-dysmetabolic, or infectious etiology (periventricular leukomalacia, cortical and subcortical encephalomalacia) have been described. Hemispheric anomalies in newborns with optic nerve hypoplasia can be considered as an unfavorable prognostic criterion indicating future neurological abnormalities. Neurological symptoms are seen in 20 % patients with optic nerve hypoplasia.

In 1956, G. sk-Morsier described the so-called septo-optic dysplasia, which includes the following triad of symptoms: optic nerve hypoplasia, agenesis or thinning of the corpus callosum and septum pellucidum (Fig. 13.4).

Endocrine dysfunctions are determined by 27-43 % children with optic nerve hypoplasia. Posterior pituitary ectopia, which is essentially a pathognomonic sign of anterior pituitary hormone deficiency, is detected on MRI in about 15 % patients with optic nerve hypoplasia. Growth hormone deficiency is the most common endocrine disorder associated with optic nerve hypoplasia. Less common are other endocrine disorders: hypothyroidism, panhypopituitarism, diabetes insipidus, hyperprolactinemia.

Hypoplasia of the optic nerve is a symptom that is important for the differential diagnosis of some malformations: Patau syndromes (trisomy 13 th chromosome), Alert, Warburg, Meckel-Gruber, Zellweger disease or cerebrohepatorenal syndrome. Identification of optic nerve hypoplasia in patients with Warburg syndrome (an autosomal recessive oculocerebral syndrome) is a diagnostic "key" to distinguish this disease from common neural tube defects.

Cases of unilateral and bilateral optic nerve hypoplasia have been described in children with frontonasal dysplasia and basal encephalocele, as well as in patients with Yadassohn's epidermal nevus. D.A. Thompson et al. (1999) reported a patient with bilateral optic nerve hypoplasia, achiasmia (non-crossing retinal fiber syndrome), cleft lip and hard palate, nasosphenoidal encephalocele, agenesis of the corpus callosum, and absence of the falx cerebrum. The combination of bilateral optic nerve hypoplasia with achiasmia, absence of optic tracts, and focal polymicrogyria of the left perisylvian region in a 5-month-old infant was described by K. Waheed et al. (2002).

Optic nerve hypoplasia occurs in 30-57 % of patients with Eicardi syndrome, which is characterized by agenesis of the corpus callosum, myoclonic seizures, mental retardation and lacunar chorioretinal lesions.

visual functions. Visual acuity in optic nerve hypoplasia varies from 1,0 to "lack of veto-feeling".

Visual field disorders detected in patients with optic nerve hypoplasia are quite diverse: local central and / or peripheral loss, hemianoptic defects, concentric narrowing.

Lower nasal and lower hill-like visual field defects are described in children with upper segmental optic nerve hypoplasia born to mothers with insulin-dependent diabetes mellitus. Optical coherence tomography in these patients shows segmental thinning of the retinal nerve fiber layer and (in some cases) abnormal enlargement of the retinal pigment epithelium-choroidal complex over the edge of the lamina cribrosa.

The polymorphism of visual field defects is explained by the variety of morphological disorders in patients with optic nerve hypoplasia. Hypoplastic can be not only the disc and the optic nerve, but also the chiasm, the optic tract, and any segment of the retrogenicular visual pathways, such as optic radiation. Hypoplasia of visual radiation is described by M. Brodsky et al. (1997) in a child with congenital peripapillary staphyloma, atypical hemimegacephaly, and Yadasson's seborrheic nevus. In patients with combined hypoplasia of the optic nerve, chiasm and / or retrogenicular visual pathways, hemianoptic or quadrantoptic visual field defects are determined. Violations of color vision, as a rule, are not detected.

Electrophysiological studies. ERG with optic nerve hypoplasia usually remains normal, while G. Cibis and K. Fitzgerald (1994) found a decrease in ERG amplitude in 42 % patients with optic nerve hypoplasia. The authors explained the detected changes by transsynaptic degeneration of the structures lying distal to the ganglion cells, which, however, was not convincingly argued.

The electrooculogram in isolated optic nerve hypoplasia does not change. The most informative test for assessing visual functions in children with optic nerve hypoplasia is the registration of visual evoked potentials (VEP). The amplitude and latency values ​​of the main positive P100 component of VEP in optic nerve hypoplasia correlate with the size of the optic disc. This dependence is probably due to the number of neurons involved in the generation of responses. With an optic disc diameter of 0,1 before 0,25 Taxiways (see Figure 13.1) VIZs are generally not recorded (Figure 13.5). Visual acuity in these children usually fluctuates within the "O - correct light projection."

Neuroradiological and ultrasound studies. CT of the orbit and the brain in some cases can determine the thinning of the optic nerve in its orbital part (Fig. 13.7), as well as a decrease in the diameter of the optic opening of the orbit, hemispheric migration anomalies, periventricular leukomalacia, encephalomalacia, anomalies of the structures of the midline of the brain (underdevelopment or agenesis corpus callosum, lack of a transparent septum), etc.

MRI is the optimal non-invasive diagnostic method in terms of its resolving capabilities, as it allows not only to establish the correct diagnosis in controversial cases, but also to conduct a rather complex differential diagnosis with various neuroendocrine diseases, often combined with optic nerve hypoplasia.

When using coronal and sagittal sections, it is possible to detect a decrease in the diameter of the intraorbital and intracranial parts of the optic nerve, diffuse thinning or absence of chiasm in a bilateral process (chiasmal hypoplasia or achiasmia), hypoplasia of the optic tract, hypoplasia or posterior ectopia of the pituitary gland, and anomalies of structures of the midline of the brain.

The detection of infundibular hypoplasia or posterior pituitary ectopia in children with optic nerve hypoplasia during MRI is a prognostic criterion indicating the development of endocrine insufficiency in the future.

According to neuroradiological studies, agenesis of the corpus callosum and/or septum pellucidum is determined in 46-53 % patients with optic nerve hypoplasia, other CNS malformations - in 12- 45 % cases.

Differential diagnosis. Despite the characteristic ophthalmoscopic picture, the correct diagnosis in patients with optic nerve hypoplasia is often established only at an older age. Problems in ophthalmoscopic diagnosis in infants are usually associated with their active behavior during examination. Often, patients are observed for a long time with a diagnosis of optic nerve atrophy. Differential diagnosis Optic nerve hypoplasia and atrophy usually cause difficulties in bilateral lesions and based only on ophthalmoscopy findings in patients with optic nerve hypoplasia, the disc may be white or gray, but it is always reduced in size. Additional signs that testify in favor of optic nerve hypoplasia are the “double ring” symptom and corkscrew tortuosity of the vessels.

Difficulties in interpreting the ophthalmoscopic picture may arise when examining patients with high hyperopia, when the study creates a false impression that the optic nerve head has a smaller diameter.

In difficult cases, auxiliary diagnostic methods are used:

• calculation of the ratio of the distance "disk-macula" to the diameter of the disk (normally< 3) при обычной фоторегистрации;
• measurement of disk parameters using a computer disk analyzer;
• photography of the fundus in redless light with high resolution, which allows to determine the defect in the layer of nerve fibers;
• study of the thickness of the layer of nerve fibers using optical coherence tomography, which is especially informative in the presence of appropriate changes in the field of view.

Optic nerve hypoplasia must be differentiated from its aplasia. These conditions have clear clinical differences: with optic ring hypoplasia, even if the disk of the optic ring is practically indistinguishable, the central retinal vessels are always determined, which have a normal caliber and a corkscrew course.

If an optic nerve hypoplasia is detected in a young child, the ophthalmologist should rule out possible subclinical endocrine or neurological disorders as soon as possible.

A thorough examination using immunobiochemical and neuroradiological methods will allow diagnosing neuroendocrine disorders even before the clinical manifestation of the disease and prescribing adequate therapy to the child, which will prevent the development of irreversible complications. In these situations, the use of MRI helps to obtain information necessary for differential diagnosis and neurosomatic prognosis. A history of neonatal jaundice in infants with optic nerve hypoplasia suggests secondary hypothyroidism, while neonatal hypoglycemia or seizures suggest panhypopituitarism. Therefore, MRI should be used to rule out secondary neonatal hypothyroidism in infants with optic nerve hypoplasia. Due to the obvious difficulties in assessing the normal level of somatotropin, most patients with optic nerve hypoplasia should be under the supervision of a pediatrician. With growth retardation, biochemical studies are necessary to confirm the diagnosis. In children with optic nerve hypoplasia, hypoglycemia, neonatal jaundice, and posterior pituitary ectopia on MRI, anterior pituitary hormonal insufficiency is usually noted. Such patients are shown to conduct a detailed endocrinological examination.

Agenesis of the septum pellucidum and/or corpus callosum detected by NSG, CT or MRI is not a reliable sign of neurological disorders or hormonal deficiency. Predicting the appearance of neurological abnormalities in infants with optic nerve hypoplasia and hypo- or agenesis of the corpus callosum or septum pellucidum is possible only if these malformations are combined with hemispheric migration anomalies.

Treatment. Some authors are skeptical about the treatment of patients with optic nerve hypoplasia. Our experience shows that rehabilitation attempts made at an early age in children with optic nerve hypoplasia in some cases lead to positive results. In addition, some development of visual functions in children of the first year of life with optic nerve hypoplasia may be due to the ongoing maturation of pre- and post-genicular visual pathways and cortical centers. It is known that to 6 at the age of one month, the volume of the lateral geniculate body of a person increases in 2 times, before 4 th month in the postnatal period, the number of spines on the dendrites and soma of neurons increases. Synaptogenesis in the field 17 According to Brodman, it reaches its peak at 8 th month of life, simultaneously there is an increase in the width of the cortex in all visual fields. The described processes, which are characteristic of healthy infants, also occur in children with optic nerve hypoplasia. Due to the plasticity of the nervous system in young children, treatment during this period allows achieving better functional results.

Rehabilitation of children with optic nerve hypoplasia primarily involves the elimination of the fatal effect of visual deprivation on the maturing visual system. In this regard, the functional rehabilitation of children with optic nerve hypoplasia primarily includes measures to prevent the development of amblyopia (refractive, dysbinocular, etc.) and its treatment. Children with optic nerve hypoplasia should be given as early as possible spectacle or contact correction of ametropia, dosed occlusion of the better seeing eye with unilateral or asymmetric damage, laser pleoptics and transcutaneous electrical stimulation of the optic nerve. Surgical treatment of strabismus is possible with a cosmetic or, in the presence of high visual acuity, a functional goal (development of binocular vision). At the same time, it is necessary to correct somatic and neuroendocrine disorders.

One of the most unfavorable processes occurring in the optical apparatus of the eye is the death of its nerve fibers. This pathology is called atrophy. The optic nerve serves as a bridge connecting the brain and eyes. Thanks to his work, a person can not only see, but also be aware of what he sees.

With the help of impulses, information comes from the organ of vision directly to the parietal lobe of the brain and its cortex. The processing of the received data is carried out and the person can see and realize what is in front of him. This process is so sharp and lightning fast that people do not notice it. However, any pathological changes in the optical apparatus immediately become noticeable and make themselves felt.

Complete atrophy of the optic nerve or destruction or death causes many serious consequences for the eyes. Dead fibers are unable to transmit impulses to the brain. Therefore, patients face partial or complete loss of the ability to see, depending on how much the nerve has been damaged. Fields of vision may be narrowed, and color perception may be disturbed. All these changes will be reflected in the study of the optic nerve head. The ICD code encodes the pathology as H47.

According to statistics, this disease occupies only 1 - 1.5% of the total mass of ophthalmic ailments. However, 20 to 25% can lead to atrophy and blindness. At the cellular level, there is a destruction of the nerve elements in the retina and their transformation, which affects the capillary network of the optic nerve and its trunk. As a result, it becomes thinner and dies, losing its functional purpose.

The reasons

Atrophy is a consequence of many pathological processes. Depending on the factors that caused it, the disease can be divided into 2 types:

• Hereditary or congenital optic nerve atrophy, which may present in infants and older children. The provocateur of this condition is usually a genetic defect or mutation in the chromosome. Leber's optic nerve atrophy and optic nerve hypoplasia are common;
• Acquired, which occurs in adults due to various diseases that have appeared over the course of life.

The second group of atrophies is common. Acquired pathology occurs in the following conditions:

• Glaucoma;
• Squeezing of the vessels that feed the nerve, tumors or abscess;
• myopia;
• atherosclerosis;
• Thrombosis;
• Inflammatory processes in the vessels - vasculitis;
• arterial hypertension;
• Diabetes;
• Traumatic injury;
• Intoxication of the body due to SARS, alcohol or drugs, nicotine.

Another common classification is the division of the atrophic process depending on the location of the lesion. Destruction can be:

• Ascending, in which damage affects the eye and has not yet reached the optic nerve. The pathological process goes in the direction of the brain, spreading from the upper layer of the eye inwards. More common in glaucoma and myopia;
• Descending, developing when the process moves to the optic nerve head, which is located on the retina. This damage occurs with aplasia or hypoplasia of the optic disc, retrobulbar neuritis and trauma in the area of ​​the chiasm, as well as with pituitary neoplasms.

Symptoms

The manifestations of optic neuropathy depend on its type. Depending on where the destructive process is located, how damaged the fibers are and clinical signs will form. The main symptoms of the destruction of the optical apparatus are:

• Reduced visual acuity - amblyopia. At the same time, the patient sees the world around him indistinctly, it becomes difficult for him to see the objects around him;
• Change in the field of view - anopsia. Normally, this is the whole picture that a person sees without blinking, looking in front of him. If this function is impaired, "tunnel vision" may occur. At the same time, the world is seen as if through a spyglass. Another disorder is the appearance of mosaic dark spots before the eyes. In this case, some part of the image may be missing;
• A change in color vision that makes it difficult to recognize different shades. First, the ability to distinguish green falls out, and then red;
• Slow recovery of optical functions when moving from illuminated space to darkness, and vice versa.

Each of the emerging signs gives the patient inconvenience and immediately attracts attention. Do not ignore the warning signs. The earlier medical care is provided, the higher the chance of maintaining health.

Diagnostics

To identify the disease, an ophthalmologist should conduct a comprehensive examination that will help establish the criteria for atrophy. Patients are assigned instrumental diagnostics, which allows to differentiate the pathology of the visual apparatus from the brain. The most common research methods are:

• Ophthalmoscopy, which allows you to identify the state of the optic nerve head at the moment;
• Perimetry helps in determining the edges of the field of view and identifying their defects - cattle;
• Color testing, which aims to detect the pathology of hue recognition;
• B-scanning ultrasound of the eye;
• Computed tomography (CT);
• Angiography of the vessels of the retina and brain, to determine the location of impaired blood circulation;
• Craniography or radiography of the bones of the skull. This is necessary to identify the condition of the bone canal of the optic nerve. This method is aimed at discovering what may be causing the alleged compression;
• Magnetic resonance imaging (MRI) allows you to clearly see the fibers of the nervus opticus and assess their structural condition;
• Laboratory blood tests to check for the presence or absence of inflammation or infection.

A genetics consultation may be scheduled, which will reveal whether the pathology was inherited or acquired during life.

Treatment

It is not possible to overcome atrophy of the optic nerve. Modern medicine gives a chance to stop the development of the pathological process. The main goal is to eliminate the underlying disease that caused the destruction. Depending on the initial process, the treatment will be appropriate.

With viral etiology of atrophy, antibiotic therapy is needed. In the presence of a tumor or cyst, an examination by a neurosurgeon is required. To improve the condition of the visual apparatus, treatment is carried out by:

• Physiotherapy with the use of electrophoresis, magnetostimulation, ultrasound, oxygen therapy;
• Medicines from the group of angioprotectors and vasodilators;
• Reflexology.

Suspension of the development of pathology at the beginning gives a chance not to go blind. The later the appropriate treatment is started, the worse the consequences for the patient. If the patient's vision has reached a level below 0.01, then the therapy will not be effective.

Modern methods of treatment

Today, medicine is trying to find a way to cope with optic nerve atrophy. For this, many research experiments are carried out. Stem cell therapy deserves great attention. Many medical industries are pinning their hopes on this method of therapy. Ophthalmology is no exception.

Stem cells are the primary link in any body system. Progenitor of everything. They form all the cells of the body. Before specializing, they are stem and contain active substances - cytokines and interleukins, as well as growth factors. They are needed to create new cells. Mastering the technology of handling these structures presents great opportunities for medicine. In particular, to create new organs and tissues.

To grow the optic nerve to replace the atrophied one, scientists, unfortunately, are not yet within their power. However, this practice still exists today. With the help of an injection, the patient is injected with stem cells into the region of the optic nerve. This manipulation is carried out every 2 hours 10 times a day.

However, this procedure is difficult due to the need for surgical intervention. Therefore, the method was somewhat modified. Now, stem cells are transplanted to patients in 3 procedures with a time interval of 3 to 6 months. Plain lenses are used for the base of the stem cell carrier. The procedure has received good reviews from patients, however, its cost is high.

Physiotherapy

One treatment for optic nerve atrophy that has been unfairly overlooked is physiotherapy. The impact is carried out with the help of special devices and medicines. You can be treated with the help of physiotherapy by:

• Acupuncture;
• electrophoresis;
• Magnetic, laser, radiation and electrical stimulation of the optic nerve.

These methods allow to normalize blood supply and metabolic exchange in the affected optical structure. With hypoplasia of the optic nerve, this is impossible due to the fact that the pathology arose due to underdevelopment at the embryonic level.

Surgery

If the nerve is compressed, surgery may be indicated. Normally, the optic nerve freely passes through the bone canal. He should not have any obstacles in his way. With pathological changes in the bone skull or neoplasms, there is a block for the passage of fibers. In addition, the feeding vessels are also pinched. Ischemia of the optic nerve develops.

Surgical intervention helps to eliminate the compression of the fibers, increase the diameter of the vessels that feed it. Nerve ischemia may be reversible. Surgical operations performed for atrophy are as follows:

• Vasoreconstructive;
• Implantation of electrodes into the optic disc;
• Revascularization.

Forecast

The outcome of the disease will depend on some factors - on the time of the onset of the process, on localization, on the assistance provided, as well as on the patient's concomitant diseases. Whatever the atrophy of the optic nerve is, it is an irreversible process. The ability to see cannot be fully restored. But it is possible to suspend pathological destruction. Loss of vision or its reduction may cause the patient to be assigned a disability group in the ITU.

Video

Optic nerve hypoplasia is a congenital condition in which a person's optic nerve is smaller than normal. This results in poorly developed vision, which can range from slightly reduced vision in only one eye to total blindness. Additional hormonal and developmental abnormalities are often associated with this condition. Optic nerve hypoplasia is usually diagnosed in children between the ages of three and four.
Early signs of this condition may include unusual eye movements called nystagmus, which is eye movement without focus or purpose. Regardless of the condition, it can be a sign of poor vision in children. The damage caused by this condition is consistent and does not worsen over time.

Problems with optic nerve hypoplasia often spread through the eyes to the brain. Many with this condition also suffer from abnormal brain function, which can range from very mild to severe. Abnormal brain function is usually caused by De Morsier syndrome. This disorder, also called septo-optic dysplasia, is caused when the brain's septum pellucidum is not fully formed.

When this part of the brain is underdeveloped, it can lead to minor or major problems with motor function, speech, and intelligence. Seizures are also common in children with this condition, but they can usually be controlled with special medications.

Children suffering from underdevelopment of the optic nerve may also have a poorly functioning pituitary gland. The pituitary gland is responsible for the body's release of hormones that control everything from the body's metabolism to sexual development later in life. If the pituitary gland does not produce these hormones, then the child may be given hormonal supplements to compensate for their absence.

With optic nerve hypoplasia, it is impossible to improve a child's vision. Due to the wide variety of conditions and disabilities associated with this condition, affected individuals usually need to be under the regular care of an ophthalmologist, endocrinologist, and neurologist. Sometimes social workers and other helpers are also involved to provide the best possible care for the child.

Children with optic nerve hypoplasia can sometimes go to school with non-disabled children, but if their brain function is highly dependent on the condition, this may not be possible. Regardless of the type of education a child receives, they need additional tools, such as special books in large print or a magnifying glass, that make it easier to read small text. They may also need to participate in speech therapy and other additional services to improve their overall state of life.

3855 0

Aplasia and hypoplasia of the optic disc

One of the variants of the anomaly is aplasia of the nervous structures with the normal development of mesodermal elements in the optic nerve trunk and central vessels. This anomaly is called aplasia of the disc or the third neuron, the retina.

Optic disc hypoplasia is more common than optic disc aplasia, but also quite rare. With hypoplasia, the optic disc in one or both eyes is reduced in size to 1/3-1/2 of its normal size. Often it is surrounded by a zone of pigmentation. The vascular system of the disc is normally developed, tortuosity of the vessels is less often noted. An x-ray examination sometimes reveals a decrease in the size of the optic opening, which indicates the spread of hypoplasia in the proximal direction.

Hypoplasia of the optic disc is often combined with microphthalmos, aniridia, underdevelopment of the orbit. At the same time, there may be a delay in psychophysical development, hemiatrophy of the face on the side of the lesion. Visual functions are sharply impaired and depend on the degree of hypoplasia. With a combination of hypoplasia of the optic nerve head with nystagmus and strabismus, as well as its mild severity, it is necessary to carry out differential diagnosis with amblyopia.

The anatomical essence of aplasia and hypoplasia of the optic disc is the absence of all or part of the optic nerve fibers. The anomaly occurs as a result of a delay in the growth of fibers into the optic nerve canal, as a result of which they do not reach the disc.

Pits (depressions) in the optic disc- a common congenital anomaly, the pathogenesis of which is not entirely clear. VN Arkhangelsky (1960) considers it as a variant of disc hypoplasia with a partial delay in the ingrowth of nerve fibers, other authors associate the formation of pits with the introduction of rudimentary retinal folds into the intervaginal spaces of the optic nerve.

The pits are easily detected by ophthalmoscopic examination in the form of darkish spots (since their bottom is not illuminated by an ophthalmoscope) with clear edges, oval, round and slit-like. More often, the pits are located in the temporal part of the disc, closer to its edge. Their size ranges from 1/2 to 1/8 of the disk diameter, the depth varies from slightly noticeable to 25 diopters, sometimes the bottom is not visible at all. Often it is covered with a grayish veil-like fabric; Vessels may be visible at the bottom. The anomaly is usually unilateral. The pits can be single (more often) and multiple (up to 2-4). The central vessels, as a rule, are not changed and bypass the fossa. In more than half of the cases with this anomaly, the cilioretinal artery is detected in the eye.

The functions of the eye are often not changed. However, visual field defects can be detected: an increase in the blind spot, sectoral loss, less often central and paracentral scotomas. Reduced vision is usually associated with a variety of macular changes - from the picture of central serous retinopathy, edema of varying severity, macular cysts, hemorrhages, various pigmentary disorders to gross degenerative foci.

The pathogenesis of changes in the macular zone is not entirely clear. Due to the location of the pits in the temporal part of the disk, the nutrition of the macula may be disturbed. The results of fluorescein angiography indicate the presence of subretinal fluid flow from the fovea to the macula, which is obviously associated with impaired vascular permeability in the fovea.

Enlargement of the optic disc (megalopapilla)- a rare anomaly, unilateral or bilateral. The disks can be enlarged to varying degrees, sometimes almost doubling their area is noted. The anomaly is most likely associated with an increase in the amount of mesodermal or supporting tissue in the invasion of the optic stalk. Visual acuity can be reduced to varying degrees.

Optic disc inversion- its reverse, inverted location. It differs from the usual state only in the ophthalmoscopic picture: there is a rotation of the disc by 180 ° or, less often, 90 ° or less. Disc inversion can be combined with a congenital cone, often accompanied by refractive errors, resulting in reduced visual acuity.

Heterotopic optic disc

Congenital excavation of the optic disc- oblique location of its scleral canal, outwardly similar to glaucomatous excavation. It is formed due to the oblique course of the optic nerve canal, while the disk has the shape of a vertically located oval, its nasal edge is pushed forward and hangs somewhat, the course of the vessels passing through it, as in conventional excavation. Often associated with refractive errors.

Doubling of the optic nerve head is more often combined with doubling along a certain length of the nerve itself. A rare anomaly is often unilateral. In the fundus, two discs are revealed, each with its own vessels. The secondary disk is usually smaller, often connected to the edge of the main disk, and can be located in any position. The degree of doubling may be less pronounced: ophthalmoscopically on one disc, the retinal vessels emerge from two different recesses.

Congenital pseudoneuritis (false neuritis) one of the most frequently observed anomalies of the optic nerve (up to 0.2% in the population). In most cases, the anomaly is bilateral (up to 80% of cases). Sometimes it manifests itself in the form of a family pathology. The morphological basis of the anomaly is hyperplasia of glial and connective tissue in the intraocular portion of the optic nerve.

The clinical picture is represented by signs of neuritis: the optic disc is hyperemic, with indistinct boundaries. At small degrees, only the nasal border of the disk is fuzzy, in a pronounced form - all borders are washed away. Atypical branching and tortuosity of the vessels on the disc are often observed, but their caliber is not changed. In most cases, hypermetropia of a high degree is observed.

Pseudoneuritis it is necessary to differentiate from true neuritis, papillitis, in contrast to which, with pseudoneuritis, there is no peripapillary edema, hemorrhages and exudate on the disc, vessels of normal caliber, the process does not progress, visual functions are not impaired. Visual acuity in pseudoneuritis can be reduced due to refractive error and increases with its correction. Children with pseudoneuritis should be under dispensary observation and should be consulted by a neuropathologist and an otolaryngologist.

Myelinated fibers of the optic disc and retina- one of the most common anomalies in which myelination captures the fibers of the optic nerve and extends beyond the cribriform plate into the eye to the disc and retina. A characteristic ophthalmoscopic picture is observed: shiny white spots with jagged uneven edges, shaped like flames, fox tails, fan out from the disk to the retina, covering its vessels. Vision is usually not impaired, the blind spot is enlarged. Visual acuity can be reduced with the localization of myelin fibers in the macular region.

Pigmentation of the optic disc is characterized by the deposition of clumps of pigment on the disc, more often in the region of the vascular funnel, along the vessels. Less commonly, the entire disc is covered with pigment. Visual functions, as a rule, are not disturbed.

The source of pigment in this anomaly can be retinal pigment epithelium cells or choroidal chromatophores, which penetrate the disc tissue during the existence of the germinal fissure, entering the eye along with the central vessels. The pigment is localized in the layer of nerve fibers. Pigmentation of the disc can also be observed with melanosis of the eye, when an intensely pigmented cribriform plate is visible during ophthalmoscopic examination.

Congenital cone ophthalmoscopically is a white crescentic (crescent) zone at the edge of the optic disc. Unlike the myopic cone, it can be localized in any part of the disc, most often in its lower sections. The disc itself is oval, its long axis is parallel to the axis of the cone.

Pathogenetically, the formation of a congenital cone is associated with a defect in the closure of the embryonic fissure. In the cone zone, there is a defect in the development of the pigment epithelium, Bruch's membrane, the nuclear layer of the retina and the choroid. The bottom of the cone is formed from the sclera, over which the unchanged fibers of the optic nerve pass. On the opposite side of the cone, the choroid and retina, on the contrary, protrude into the optic nerve, forming a sharp, raised edge here.

With pigmentation, a decrease in visual acuity is often observed due to concomitant anomalies, more often hyperopic astigmatism of high degrees.

Optic nerve coloboma

The appearance of an optic nerve coloboma, like other colobomas, is associated with a violation of the process of closing the germinal fissure. Colobomas vary in shape and size. In place of the optic nerve head, a round, oval or triangular recess with clear boundaries, bordered by pigment, is visible. The dimensions of this recess are 2-3 times larger than the diameter of the disk itself. The true borders of the disk are not visible and are only outlined against the background of a large choroidal defect in the upper part of the coloboma.

The vascular bundle is located in different areas and is significantly changed. One part of the vessels (usually the upper ones) comes out of the optic disc itself, the other is much lower and bends over the edge of the choroid and retina. Vessels can also exit in one bundle or evenly along the entire edge of the coloboma. Vision in colobomas of the optic nerve is usually significantly impaired.

Less commonly observed is a form of optic nerve coloboma called "peripapillary true staphyloma", in which the normal disc is located at the bottom of the recess of the correct cylindrical shape.

Syndrome "morning light"- a congenital anomaly of development, in which the optic disc is significantly enlarged, grayish in color, with a deep funnel-shaped excavation, resembles a flower in shape. In the center of the disk, in place of the missing central vessels, there is a gray-white tissue; numerous vessels of reduced caliber emerge along the edge. A wide grayish ring of pigment forms around the disc. Visual acuity is sharply reduced. The anomaly is often combined with the persistence of the vitreous body artery (posterior portion of the primary hyaloid system), congenital cataract, high myopia, astigmatism.

Drusen of the optic disc

There are superficial (explicit), deep, hidden and amputated drusen. Superficial drusen are whitish or yellowish, translucent, rounded, single or multiple formations in the form of conglomerates protruding above the surface of the disc. They are more often localized at the nasal edge of the disc or near the vessels, they can be located in the center of the disc, as well as in the peripapillary region. Irregularly shaped disk edges due to protruding drusen, which are better seen in indirect red light.

With a pronounced process, the disk is enlarged, protrudes into the vitreous body. Deep drusen are not visible with conventional ophthalmoscopy, they are not detected with oblique illumination in indirect red light. Hidden drusen are located deep in the tissue of the optic disc and appear only in the pathological prominence of the disc.

Druses are characterized by an unusual structure and arrangement of vessels: the presence of a cilioretinal artery, early branching of the vessels, their tortuosity, an unusual course with the presence of inversions, vascular bundles, loops. In rare cases, hemorrhages occur due to compression of blood vessels or direct influence on them. Hemorrhages, usually small, can be observed in the nerve fiber layer of the disc, in the vitreous body, and also in the peripapillary region.

Visual acuity with drusen is not reduced, however, visual field defects are observed in 80-90% of patients.

In children, optic disc drusen are often associated with various neurological disorders in the form of symptoms of mild brain dysfunction, as well as migraine and epileptiform symptoms. Almost 50% of patients have an abnormal EEG. The presence of these signs indicates that drusen are only a local sign, reflecting a more extensive developmental disorder in the embryonic period.

Drusen must be differentiated from congestive optic papilla, for which it is necessary to conduct repeated ophthalmoscopic and campimetric studies to exclude it.

The posterior primary hyperplastic vitreous body arises as a result of a violation of the reverse development of the primary embryonic vitreous body and the hyaloid system, refers to anomalies in the development of the vitreous body. However, there are often cases when the changes are limited to the region of the posterior pole of the eye, such an anomaly is considered in the section of the pathology of the optic nerve. Patients usually go to the doctor about monocular vision loss or strabismus.

The anomaly is usually unilateral. Ophthalmoscopy reveals a deformed optic disc, often with indistinct boundaries. There is no physiological excavation, the disc is decolorized. In 50% of patients, radial retinal folds and cords, preretinal gliosis from the disc to the macula are observed. Changes in the vessels of the disc are characteristic - their tortuosity, unevenness, abnormal branching, the formation of loops. The anomaly must be differentiated from inflammatory diseases and other congenital anomalies of the optic nerve. Treatment is not carried out.

Inflammatory diseases of the optic nerve, neuritis

Selection of a special shape- papillitis, or neuritis proper, due to the fact that the disk is the only visible part of the optic nerve and is morphologically different from its other departments. The fibers of the disc are devoid of myelin sheath, there are no connective tissue jumpers in its structure. The disc can be involved in the process in various intraocular pathologies (uveitis, endophthalmitis, etc.). The inflammatory process of the optic nerve often extends both to its trunk and to the sheaths, much less often limited to one sheath and surface layers of nerve fibers.

Accordingly, neuritis and perineuritis are distinguished. Inflammatory process in the trunk of the optic nerve of an interstitial nature, nerve fibers are involved in the process for the second time. Accumulation of exudate in the intervaginal spaces, small cell infiltration of tissues leads to compression and swelling of the nerve fibers, its hypoxemia and hypoxia, hemorrhages in the nerve tissue, proliferation of connective tissue elements, as a result of which atrophy of the nerve fibers develops, which are replaced by connective tissue and neuroglia.

The cause of the development of neuritis can be inflammatory diseases of the brain and its membranes (meningitis, encephalitis, brain abscess), acute and chronic infections (flu, measles, chicken pox, brucellosis, mumps), foci of local inflammation (sinusitis, diseases of the teeth, nasopharynx ), diseases of internal organs, helminthic invasions, inflammatory diseases of the eyeball and orbit, intoxication, metabolic diseases, etc.

Determining the etiology of neuritis often presents great difficulties; in 30-50% of children, the etiology cannot be established.

Optic neuritis (papillitis)- inflammatory process in its intraocular part. Neuritis is relatively more common in children than in adults. In the acute phase of the disease, children complain of decreased vision, headache (more often than in adults), and sometimes pain when moving the eyeballs. The ophthalmoscopic picture is characterized by hyperemia of the optic disc, blurring of its borders, moderate expansion and in some cases tortuosity of the vessels, the appearance of exudate on the surface of the disc, along the vessels, in the vascular funnel.

Hemorrhages may occur in the disc tissue and retina. With pronounced neuritis, the disc almost merges with the surrounding tissue, its entire surface is covered with hemorrhages and whitish foci of exudate, opacities appear in the posterior layers of the vitreous body. Neuritis is characterized by the absence of disc prominence; its standing, if observed, is very insignificant and rarely exceeds 1.0-2.0 diopters.

The process is more often unilateral, but bilateral lesions in children are observed more often than in adults - in 30-50%.

Visual functions are disturbed early and abruptly, which is associated with both the destruction of part of the nerve fibers in the focus of inflammation and the dysfunction of the remaining fibers. The degree of reduction in visual acuity is different and depends on the involvement of the papillomacular bundle in the process. At the same time, color perception is disturbed. Changes in the visual field are more often manifested in a uniform or uneven narrowing of its boundaries; central and paracentral scotomas may occur.

The diagnosis of optic neuritis is established on the basis of the characteristic picture of the fundus and visual impairment. It is advisable to use direct ophthalmoscopy in redless light, which allows to detect small hemorrhages. Differential diagnosis is carried out with congestive optic papilla and pseudoneuritis.

Retrobulbar neuritis- inflammation of the optic nerve behind the eyeball, between the eyeball and the chiasm.

Conditionally allocate inflammation of the membranes - perineuritis, peripheral interstitial neuritis and axial, or axial neuritis with lesions of the papillomacular bundle. The latter is the main, most common form of retrobulbar neuritis. These types of damage to the optic nerve can occur in various combinations, characterized by a variety of symptoms. The defeat is predominantly unilateral.

The main reason for the development of retrobulbar neuritis in children, as in adults, is multiple sclerosis observed in 20-80% of patients. The disease is more typical for young people, but it is also observed in children. Damage to the optic nerve may be the only sign of this severe disease for a long period (10-15 years). It is characteristic that in multiple sclerosis, retrobulbar neuritis can recur, proceeding for a long time. The appearance of any general symptoms (severe fatigue, weakening of the abdominal and other reflexes) should alert the ophthalmologist.

In addition to multiple sclerosis, acute and chronic retrobulbar neuritis can be caused by various infectious diseases, inflammation of the paranasal sinuses, encephalomyelitis accompanied by demyelination of nerve fibers, etc.

Retrobulbar optic neuritis is manifested by a rapid decrease in visual acuity, the appearance of central and paracentral scotomas in the field of vision, color perception disorders. A characteristic symptom is pain during movements of the eyeball, which is associated with the involvement in the inflammatory process of the tendon ring, from which almost all the external muscles of the eyeball begin.

Changes in the fundus are minor and depend on the localization of the process. With inflammation of a part of the nerve that is significantly remote from the eyeball, the fundus, as a rule, does not change; in cases of localization of the process in the area located close to the disk, mild signs of neuritis appear - slight hyperemia and blurred borders of the disk, slight dilatation of the veins.

Pronounced changes in the fundus are observed at the end of the process, when descending atrophy of the optic nerve develops. Often there is a blanching of the temporal half of the disk, which is associated with a predominant lesion of the papillomacular bundle in retrobulbar neuritis. The course of the disease can be acute and chronic. The prognosis is more favorable in the acute course of the process.

Diagnosis of retrobulbar neuritis, based on characteristic signs, is difficult in children due to the fact that it is difficult for them to examine visual functions. It is necessary to differentiate the disease from a brain tumor, which can compress the intracranial part of the optic nerve.

Opticochiasmal arachnoiditis- inflammation of the optic nerve in its intracranial part along with the chiasm. In children, the disease is rarely observed. It often develops with basal arachnoiditis, when the inflammatory process spreads to the optic nerve and chiasm. The disease is characterized by a sharp decrease in visual acuity and changes in the visual field of the chiasmatic type.

Changes in the optic nerve head in the acute phase of the disease may be absent or be insignificant in the form of slight hyperemia and edema. In the future, after a few months, descending atrophy of the optic nerve develops. The formation of scar tissue around the chiasm and optic nerve leads to secondary pronounced atrophic changes. The disease is severe. These patients should be treated in a neurosurgical hospital.

In addition to determining visual acuity, visual field and color perception, conducting ophthalmoscopy (direct, reverse, in redless light), at present, electrophysiological methods are necessarily used in the diagnosis of optic neuritis, in particular, the study of optic nerve evoked potentials. In almost all cases, with papillits and active retrobulbar neuritis, the latent periods of evoked potentials increase, as well as the reticulocortical time, which returns to normal as it recovers. The method is especially important when examining children due to the fact that it is difficult for them to examine the visual acuity and field of view.

Fluorescent angiography reveals one of the important signs of neuritis- impregnation of vessels on the disk and fluorescence of the walls of the veins.

Treatment of optic neuritis is carried out by a neuropathologist together with an ophthalmologist. It begins immediately after the diagnosis is established. Due to the large proportion of neuritis of unclear etiology, their etiological treatment is difficult.

Broad-spectrum antibiotics are prescribed (sodium salt of oxacillin or ampicillin, gentamicin sulfate, tseporin, etc. intramuscularly and retrobulbarno), sulfanilamide preparations (etazol, sulfadimezin, sulfapyridazine, etc. inside). Non-specific anti-inflammatory treatment includes ingestion of salicylates, intravenous administration of a 5% or 10% solution of urotropin, etc.

Widely used hormonal corticosteroid drugs that have a pronounced anti-inflammatory effect. They are administered parenterally, orally, retrobulbarpo. Sanitation of foci of local infection (diseases of the paranasal sinuses, etc.), treatment of helminthiases is carried out. Dehydration agents are used (intravenous administration of a 40% glucose solution, inside diacarb, intramuscular lasix, etc.), distracting procedures (hot foot baths).

In order to improve the trophism of the optic nerve, vitamins of group B, C are prescribed. After the subsidence of acute phenomena, the use of vasodilators (nicotinic acid, nikospan), vasoconstrictive drugs (angiotrophin, dicynon, ascorutin, etc.), as well as biogenic stimulants (aloe, FiBS) is indicated , pyrogenal, autohemotherapy, blood transfusion.

To prevent the formation of scars (with optochiasmal arachnoiditis), resolving therapy (lidase, vitreous body, etc.) is used. With optochiasmal arachnoiditis, neurosurgical treatment is often carried out. Dissect moorings around the optic nerve and chiasm. The operation can be performed before the development of optic nerve atrophy while maintaining residual visual acuity.

The prognosis of optic neuritis is serious. The disease usually ends with partial or complete atrophy of the optic nerve.

Avetisov E.S., Kovalevsky E.I., Khvatova A.V.