Relevance.

The optic disc pit (ONH) is a fairly rare congenital developmental anomaly, occurring in 1 in 11 thousand ophthalmic patients. In approximately 85% of cases, the disease is unilateral; men and women are affected equally often. It manifests itself between the ages of 20 and 40 as decreased vision caused by macular disorders.

The most common complication of the optic disc fossa is retinal separation (schisis) in the macula. One of the probable causes of the formation of retinoschisis in the macular area is the flow of cerebrospinal fluid from the subarachnoid into the subretinal space. It is possible that intravitreal fluid penetrates through the optic disc fossa, which, if it persists for a long time, leads to the development of cystic macular edema and even a through-and-through macular hole.

Surgical treatment of the optic disc fossa consists of vitrectomy, endolaser photocoagulation and gas-air tamponade of the vitreal cavity. The effectiveness of this method is low, which requires repeated interventions.

One of the approaches to treating the optic disc fossa is to create a barrier to fluid flow into the macular area by filling the fossa with autologous sclera. This technique is quite effective, but does not exclude recurrence of macular detachment and is quite traumatic.

Recently, the technology of using autologous internal limiting membrane (ILM) to close central retinal defects has become widespread.

Target.

Development of a new technique for surgical treatment of the optic disc fossa using the ILM.

Material and methods.

Two patients with optic disc fossa were treated, aged 25 and 37 years. Visual acuity before surgery was 0.01 and 0.25, respectively.

Surgery technique: preliminarily perform transconjunctival 3-port 25G vitrectomy according to the standard technique, frequency - from 2500 to 5000 cuts per minute, vacuum - from 5 to 400 mm Hg. To detail the structure of the posterior cortical layers of the vitreous body and ILM, standard dyes are used. The separation of the posterior hyaloid membrane is carried out using aspiration technique, starting from the optic disc, gradually lifting it to the periphery.

Then the ILM in the macular zone is removed, performing a circular maculorrhexis. Next, they begin to form the ILM flap, which is carried out in several sequential steps. At the border of the maculorrhexis at 6 o'clock, using microtweezers, the tip of the ILM is separated from the retina with a pinch (action 1). Then, grasping the tip of the ILM with tweezers, the membrane is separated with a movement directed towards the inferior temporal arcade, not reaching it 0.5 mm (action 2). Next, the edge of the ILM is intercepted and it is separated along the inferior temporal arcade towards the optic disc for 2-3 hour meridians (action 3). After this, the edge of the ILM is intercepted and a movement similar to step 2 is performed, but in the opposite direction and up to the border of the circular maculorrhexis, thus separating the ILM section from the retina (action 4).

After the formation and removal of the first ILM section, the formation of the second ILM section begins. To do this, they return to the point from which they began performing step 4, separate the tip of the ILM from the retina with a pinch, then, grasping the tip of the ILM with tweezers, separate the membrane with a movement directed along the inferior temporal arcade towards the optic disc for 2-3 hour meridians (action 5) , after which the edge of the ILM is intercepted and from this point step 4 (action 6) is repeated, as a result of which the second section of the ILM is separated from the retina.

After the formation and removal of the second section of the ILM from the point from which action 6 began, a circular movement is carried out towards the inferior temporal arcade as far as the membrane allows separation (action 7).

As a result of the above steps, an ILM flap is preserved between the ILM peeling areas. This flap is turned over and placed on the optic disc.

The next step is to replace the liquid with air, then 1.5-2.0 ml of PFOS is injected and in a PFOS environment, using tweezers, a light compression effect is applied to the flap above the optic disc fossa. After this, PFOS is replaced with air under a vacuum of 30-40 mm Hg, avoiding a sharp rise in pressure during PFOS aspiration, trying to remove the liquid as much as possible and prevent displacement of the flap.

The operation is completed by introducing 1 mm³ of 20% SF6 gas into the eye cavity until mild hypertonicity is achieved.

Results.

In both cases, the intervention was performed in full; no intraoperative complications, including iatrogenic damage to the retina, were noted.

Observation period - up to 12 months. In both patients, according to optical coherence tomography, reduction of macular detachment and sealing of the optic disc fossa were observed. Visual acuity at the end of the observation period was 0.1 and 0.5, respectively.

The key stage of the proposed technique, which contributes to the achievement of favorable anatomical results, is the formation of an ILM flap and using it to close the optic disc fossa, which allows it to be sealed and to create a barrier to the flow of fluid into the macular area.

Conclusion.

The developed method of surgical treatment of the optic disc fossa is promising and requires further research on more clinical material to reliably assess its effectiveness.

Pathology of the optic nerve in most cases is a consequence of general diseases, especially diseases of the brain. There are congenital anomalies in the development of the optic nerve, inflammation (neuritis), congestive nipple, atrophy, and damage. Vascular disorders in children are extremely rare. Pathology of the optic nerve, as a rule, leads to impaired visual function, which is the main symptom that patients notice. In childhood, diagnosing diseases of the optic nerve is difficult and they are often discovered late, since children, especially preschoolers, usually do not notice visual impairment, especially with a unilateral process.

Optic nerve abnormalities

Aplasia and hypoplasia of the optic disc. Optic disc aplasia, a congenital absence of optic disc, is a rare unilateral or bilateral anomaly. It is often combined with other malformations of the eye and central nervous system. In cases of true aplasia, the optic disc and fibers, retinal ganglion cells and retinal vessels are absent. Visual functions are absent (Francois J., 1961].

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

Optic disc hypoplasia is more common than optic disc aplasia, but is 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. It is often surrounded by a zone of pigmentation. The vascular system of the disc is normally developed; tortuosity of the vessels is less common. X-ray examination sometimes reveals a decrease in the size of the optic foramen, which indicates the spread of hypoplasia in the proximal direction. Hypoplasia of the optic disc is often combined with microphthalmos, aniridia, and underdevelopment of the orbit. At the same time, delayed psychophysical development and hemiatrophy of the face on the affected side may be observed. Visual functions are severely impaired and depend on the degree of hypoplasia. When optic disc hypoplasia is combined with nystagmus and strabismus, as well as its mild severity, it is necessary to carry out a differential diagnosis with amblyopia.

The anatomical essence of aplasia and hypoplasia of the optic nerve head 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(grooves) in the optic nerve head- a common congenital anomaly, the pathogenesis of which is not entirely clear. V. N. 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 folds of the rudimentary retina into the intervaginal spaces of the optic nerve.

The pits are easily identified during ophthalmoscopic examination in the form of darkish spots (since their bottom is not illuminated by the 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 disc diameter, the depth varies from barely 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 often unilateral. The pits can be single (usually) or 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 unchanged. However, visual field defects may be detected: an increase in the blind spot, sectoral loss, and less often central and paracentral scotomas. Decreased vision is usually associated with a variety of macular changes - from a 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 disc, the nutrition of the macula may be disrupted. The results of fluorescein angiography indicate the presence of subretinal fluid flow from the fossa to the macula, which is obviously associated with impaired vascular permeability in the fovea area.

Optic disc enlargement(megalopapilla) is a rare anomaly, unilateral or bilateral. Discs can be enlarged to varying degrees, sometimes almost doubling their area. The abnormality is most likely due to an increase in the amount of mesodermal or supporting tissue due to invasion of the optic stalk. Visual acuity may be reduced to varying degrees.

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

Optic fossa It is an oval gray, white or yellowish depression of the optic nerve head. Typically, the optic nerve pits are localized in its temporal part, but can be localized in any sector. The pits located in the temporal part of the disc are often accompanied by changes in the adjacent peripapillary pigment epithelium. In more than 50% of cases, one or two cilioretinal arteries emerge from the bottom or edge of the optic disc fossa. Although most optic pits are unilateral, 15% of cases present with bilateral abnormalities.

Optic disc pits are protrusions of the dysplastic retina into a collagen-lined pocket, oriented posteriorly and often penetrating into the subarachnoid space through a defect in the lamina cribrosa. Case reports of familial cases of optic disc fossa suggest autosomal dominant inheritance.

In cases unilateral disc anomaly slightly larger than normal. In the absence of subretinal fluid accumulation, visual acuity is normal. Visual field defects are variable and often do not correspond to the localization of the optic disc fossa. The most common paracentral arcuate scotoma is observed, extending from an enlarged blind spot. Optic disc pits are rarely a symptom of concomitant CNS malformations. In normal-tension glaucoma, acquired depressions of the optic disc are described, indistinguishable from the optic disc fossa.

Serous macular detachment develops in 25-75% of eyes with optic disc pits and usually appears in the third and fourth decades of life. Vitreal traction of the edges and traction changes in the “roof” of the fossa can cause late macular detachment.

It was believed that all macular detachments, accompanying the fossa, are serous, but stereoscopic examination of the macula in combination with kinetic perimetry revealed the following changes:
1. With a schisis-like dissection of the inner layers of the retina, a communication with the optic nerve fossa is formed, as a result of which a relative centrocecal scotoma develops.
2. Beyond the separation of the inner layers in the macular region, a rupture of the outer layers is formed, causing the appearance of a dense central scotoma.
3. A detachment of the outer layers forms around the macular hole (presumably due to the entry of fluid from the zone of separation of the inner layers); this detachment resembles a detachment of the RPE, but its hyperfluorescence is not observed on fluorescein angiography.
4. The area of ​​detachment of the outer layers may increase and overlap the separation of the inner layers; such changes are ophthalmoscopically and histologically identical to primary serous macular detachment.

The final stage of the process in eyes with optic disc pits, are probably changes consistent with the histological picture of sensory retinal detachment of the macular region, but it remains unclear whether this mechanism is universal for all macular detachments in the optic disc fossa (ONH).

Risk development of macular detachment higher in eyes with large pits localized in the temporal quadrants. Perhaps, due to age-related characteristics of vitreopapillary traction, serous maculopathies in children with optic disc pits (OND) may resolve independently. Spontaneous adherence occurs in approximately 25% of cases. Most macular detachments in the optic disc pits (OND), if left untreated, lead to permanent loss of vision, even with spontaneous reattachment.

In some patients bed rest and bilateral occlusive dressings allow the retina to adhere, presumably due to a decrease in vitreal traction. Attempts to block the flow of fluid from the optic disc fossa (ONH) into the macula using laser photocoagulation have been largely unsuccessful, probably due to the inability to block the retinoschisis cavity. Vitrectomy with gas tamponade and laser coagulation provides a long-term increase in visual acuity. The source of intraretinal fluid in eyes with pitted optic discs remains unknown. Possible sources include:
1. Vitreous cavity through the fossa.
2. Subarachnoid space.
3. Blood vessels are not at the bottom of the pit.
4. The space of the orbit surrounding the dura mater of the optic nerve.

Although when fluorescein angiography There is early hypofluorescence of the optic disc fossa followed by late hyperfluorescence, leakage of fluorescein through the fovea is usually not observed, and fluorescein does not penetrate into the subretinal space of the macula. Late hyperfluorescence strictly correlates with the presence of cilioretinal arteries originating in the fossa. Slit-lamp biomicroscopy often reveals a thin membrane covering the fossa or a persistent Cloquet canal ending at the edge of the fossa. In dogs, active fluid flow from the vitreous cavity through the fossa into the subretinal space has been demonstrated. This mechanism has not been found in humans.

Pathogenesis of optic disc pits(DZN) is not clear. Most authors consider pits as a variant of optic disc colobomas. However:
1. Optic disc pits (ONP) are usually unilateral, sporadic, and not accompanied by systemic abnormalities. Colobomas are often bilateral, usually autosomal dominant, and may be associated with multisystem disorders.
2. Optic disc pits (ONP) are rarely accompanied by colobomas of the iris or retina and choroid.
3. The optic disc pits (OND) are usually localized in areas not related to the embryonic fissure.

This patient has an optic disc pit in the right eye at the eight o'clock position.
The white arrow shows the area where there was previously an accumulation of subretinal fluid, the red arrow shows the central fossa. - a congenital anomaly, which is a limited depression in the optic nerve discs. The disease occurs in the population with frequency 1: 10 LLC-11 LLC; first described by T. Wiethe (1882).

Pathogenesis. The pathogenesis of the optic disc pit is unclear. Some authors suggest that the optic disc fossa; is a mild form of optic nerve coloboma, i.e. is also caused by incomplete closure of the palpebral fissure. Its supporters cite rather rare cases of a combination of coloboma and optic disc fossa as arguments confirming this point of view.

There are facts that do not agree with this hypothesis: firstly, the disc fossae are often located in places related to the embryonic cleft; secondly, disc pits are usually unilateral, sporadic and not combined with other developmental anomalies; thirdly, disc pits are not combined with colobomas of the iris or retina. Although optic coloboma may sometimes present as a crater-shaped deformation resembling a pit of the optic disc, and it may be difficult to distinguish a lower-segment pit from a small coloboma, the facts presented above seem sufficient to demonstrate the obvious difference in the pathogenesis of coloboma and optic pits. nerve. The presence of one or more cilioretinal vessels emerging from most of the optic nerve fossae suggests that this fact is also somehow related to the pathogenesis of the anomaly.

Histological studies. In the area of ​​the fossa there is a defect in the cribriform plate. The retinal fibers descend into the fossa, then return and exit in front of the incoming optic nerve. Some fossae communicate with the subarachnoid space.

Clinical manifestations. With ophthalmoscopy, the optic disc fossa looks like a round or oval depression that is white, gray or yellow (Fig. 13.27).

The diameter of the optic disc pits varies from 1/3 before 1/8 RD. Usually the fossa is localized in the temporal half of the disc, but it can also be located in other sectors. The disease is often unilateral. The bilateral optic disc fossae meet in 15 % cases. When the lesion is unilateral, the abnormal disc appears slightly enlarged compared to the normal one.

If the disc fossa is of significant size, its sagittal section can be obtained using B-echography; for small sizes - optical coherence tomography.

Approximately in 45-75 % eyes with a congenital optic disc pit develop serous macular detachment. Lineoff et al. (1988) studied the course of development of macular complications:

The route of intraretinal fluid has not yet been precisely established. Possible moaners are indicated in the literature:

1. vitreal cavity through the fossa;
2. blood vessels at the base of the fossa;
3. subarachnodal space;
4. al vessels.

Macular retinoschisis and retinal detachment caused by the disc fossa develop with age 10- 40 years. The risk of developing macular complications is higher in cases where the optic disc fossa is large and localized in the temporal half of the disc. In cases where macular detachment exists for a long time (for 6 years or more), pigment is deposited along the edge of the disc and/or along the border of the detachment. Pigment deposits are caused by disturbances in the retinal pigment epithelium layer, in which extensive defects form over time. G. Theodossiadis et al. (1992) found that when macular detachment exists for 10 years or more, the size of the disc fossa increases, and its color becomes gray, which is probably due to the loss or restructuring of glial tissue within the fossa.

Fluorescein angiography. In the arterial and arteriovenous phases, a gradually increasing leakage of fluorescein is determined in the zone of neuroepithelial detachment towards the macula. In the early phases of FA or indocyanine angiography, the disc fossa usually does not allow contrast material to pass through. In the late phase of FA or indocyanine angiography, hyperfluorescence of the disc fossa and the area of ​​macular detachment occurs.

Psychophysical research. Visual acuity in patients with optic disc fossa remains normal until the onset of macular complications. TO 16 -adult age due to the development of macular detachment of the neuroepithelium, visual acuity 0,1 and below note at 80 % patients. Visual field defects are varied and often do not correlate with the location of the fovea. With persistent macular changes, defects in the visual field progress. Scotomas detected in the visual field correspond to defects in the retinal pigment epithelium detected by ophthalmoscopy or FA.

Electrophysiological studies. The ERG remains normal in most patients even in cases of macular complications. VVP are not changed until the development of macular detachment. With the appearance of macular complications, a decrease in the amplitude of the P100 component is noted in all cases. less often - prolongation of its latency.

Treatment. Conservative treatment, including dehydration therapy and topical corticosteroids, is ineffective. Previously, laser coagulation of the retina was used to block the flow of fluid from the disc fossa to the macula, but the effectiveness of this technique was quite low and difficult to predict due to the impossibility of adequately covering the retinoschisis cavity using laser coagulation alone. Currently, a combined technique is used, including vitrectomy followed by intravitreal tamponade with expanding perfluorocarbon gas and barrier laser coagulation. Combined treatment makes it possible to achieve improved visual acuity in all patients and anatomical success in 87 % .

Abstract

The study purpose was to evaluate the effectiveness of the central serous choroidopathy prevention method in patients with optic nerve pit. Material and methods: 19 patients (38 eyes) with optic nerve pit associated with refractive anomalies and retinal dystrophy which had been treated in Republican Eye Hospital in 2010–2012. According to obtained results the effectiveness of prophylactic neuroprotective therapy in patients with optic disc pit has been proven, which allows reducing the risk of central serous choroidopathy and avoiding the loss of visual function.

Relevance The frequency of detected congenital pathologies of the organ of vision is 2–4%. Of these, anomalies of the optic nerve head (OND) - 15%, accompanied by a decrease in visual functions - 7%. Many congenital anomalies can cause pathological conditions in adolescence or adulthood, for example: fossa, oblique entry, optic disc drusen, Leber amaurosis, etc., which account for up to 3%. It is assumed that the development of optic disc pits is associated with the introduction of folds of rudimentary retinal tissue into the space of the optic nerve. There are changes in the edge of the disc with the formation of a pocket, sometimes filled with glial tissue. Between the macula and the disc in the retina, the number of nerve fibers, neuroepithelium and outer granular layer is reduced. When the fossa is located in the temporal region, patients often experience the development of central serous choriopathy. The development of measures to prevent the development of central serous choriopathy in patients with optic disc fossa remains one of the important areas in ophthalmology and requires the search for new, more effective methods. The purpose of this work was to evaluate the effectiveness of a method for the prevention of central serous choriopathy in patients with optic disc fossa. Material and methods The material for the study was the data of a comprehensive examination of 19 patients (38 eyes) with optic disc fossae, accompanied by refractive errors and retinal dystrophies, who were treated at the Republican Clinical Ophthalmological Hospital of the Ministry of Health of the Republic of Uzbekistan from 2010 to 2012. All patients underwent standard ophthalmological examination methods: medical history, visometry, tonometry, refractometry, perimetry in white, red, green, blue colors, ophthalmoscopy with fundus photography, optical coherence tomography, study of the critical frequency of flicker fusion, electrophysiological research methods (ERG, ZVP). If necessary, the examination was supplemented with magnetic resonance imaging (MRI) of the brain, consultations with a therapist, neurologist or neurosurgeon. In order to assess the effectiveness of the proposed preventive measures, patients were divided into 2 groups. The first group (9 patients; 18 eyes) consisted of patients who were prescribed traditional therapy for the treatment of optic disc fossa and refractive errors (vitamin therapy, angioprotectors, antioxidants, barrier laser coagulation of the retina). Patients of the second group (10 patients; 20 eyes), along with traditional methods, received neuroprotective therapy (Cerebrolysin - 0.5 ml parabulbarly No. 10 and Nucleo CMF forte 2.0 intramuscularly No. 6). Terms of repeated examination: 3, 6, 10, 30, 180 days. The results of treatment were taken as data on the 180th day of examination. The groups were randomized by gender, age, underlying disease and visual function. Results of the study When assessing the effectiveness of complex therapy, we found that if before treatment visual acuity in the 1st group was 0.09 ± 0.02, and in the 2nd group - 0.07 ± 0.02, then after treatment the values These indicators increased in group 1 to 0.13 ± 0.02, and in group 2 - to 0.29 ± 0.01 (Fig. 1). As a result of traditional treatment in group 1, visual acuity increased by 0.048 ± 0.01, and in group 2 with the inclusion of neuroprotectors and laser coagulation - by 0.19 ± 0.05. Visual acuity in the second group had a significant difference from the initial values ​​(p< 0,05), в отличие от первой группы. При изучении данных электрофизиологического исследования нами также была отмечена тенденция к улучшению показателей зрительно вызванных потенциалов (ЗВП), электроретинограмм (ЭРГ) и критической частоты слияния мельканий (КЧСМ). Полученные данные представлены в виде диаграммы на рисунке 2. При использовании нейропротекторной терапии в комплексном лечении ямки ДЗН отмечалось более существенное улучшение электрофизиологических показателей, особенно ЗВП и КЧСМ, в отличие от показателей 1 группы больных. Центральная серозная хориопатия развилась на 3-х глазах в 1 группе наблюдения и ни в одном случае во 2 группе. При далеко зашедших стадиях заболевания проводились повторные курсы лечения с целью снижения риска развития отслойки сетчатки и потери зрительных функций. Заключение На основании полученных результатов считаем целесообразным назначение нейропротекторной терапии с целью профилактики развития центральной серозной хориопатии у больных с ямкой зрительного нерва. Использование нейропротекторов, наряду с традиционной терапией, у больных с ямкой диска зрительного нерва положительно влияет на динамику показателей остроты зрения, ускоряя восстановление зрительных функций.

Rustam Asralovich Zakirhodjaev

Tashkent Institute of Postgraduate Medical Education, Ministry of Health, Uzbekistan

Email: [email protected]
MD, PhD, Associate Ophthalmology Department