Retinal dystrophy: causes, symptoms, diagnosis, treatment

Retinal dystrophy occurs as a result of a disturbance of the function of the terminal capillaries, pathological processes in them.

These changes include pigmentary dystrophy of the retina - hereditary disease of the mesh shell. Pigmentary degeneration of the retina is a chronic, slowly progressive disease. Initially, the patient complains of hemorrhagia - weakening of vision at nightfall. The first symptoms of pigmentary retinal dystrophy appear at the age of up to eight years. Over time, the field of vision concentrically narrows, central vision decreases. By the age of 40-60, there is complete blindness. Pigmentary dystrophy is a process that slowly develops in the outer layers of the retina, accompanied by the death of the neuroepithelium. At the site of the deceased first neuron, pigment epithelial cells grow again into the retina of the eye, which sprout into all layers. Around the branches of the capillaries are formed pigmented congestions, which resemble the shape of "bony bodies". At first these corpuscles appear on the periphery of the retina, then their number increases, they are visible in all areas of the retina of the shell to the macular area. From the periphery, this pigmentation spreads to the center for tens of years. There may be a sharp narrowing of the caliber of the retinal vessels, they become filiform. The disc of the optic nerve changes, which acquires a waxy shade, then the atrophy of the optic nerve develops.

Over time, twilight vision is disturbed so abruptly that it interferes with orientation even in familiar terrain, and "night blindness" occurs, with only day vision remaining. The retinal rod apparatus-the apparatus of twilight vision-completely dies. Central vision is maintained throughout life, even if the field of view is narrow enough (the person looks as though through a narrow tube).

Treatment of pigmentary degeneration of the retina. The main goal is to stop the spread of end capillary involvement. To do this, apply multivitamins, nicotinic acid 0.1 g 3 times a day; preparations of the middle part of the pituitary (interludes 2 drops 2 days a week for 2 months). Apply medication (ENCAD, heparin, etc.), perform surgical interventions - revascularization of the choroid. Assign a diet poor in cholesterol and purines.

Juvenile retinal dystrophy occurs in childhood or adolescence. They note a gradual decrease in visual acuity, a central scotoma appears. The disease is genetically conditioned, often has a family-hereditary character. Distinguish the following main types of juvenile macular degeneration.

Dystrophy of the vesta. Best's disease is a rare bilateral dystrophy of the retina in the macular area, which looks like a round yellowish focus, similar to a fresh egg yolk, with a diameter of 0.3 to 3 diameters of the optic nerve disc. Type of disease inheritance Best - autosomal dominant. The pathological process is located in the macular area.

There are three stages of the disease:

• the stage of the vitelline cyst;
• exudative-hemorrhagic, at which the cyst rupture, hemorrhages and exudative changes gradually appear in the retina;
• cicatricial-atrophic.

The course of the disease is asymptomatic, it is detected accidentally when examining a child aged 5-15 years. Occasionally, patients complain of blurred vision, difficulty in reading texts with small print. Visual acuity varies depending on the stage of the disease from 0.02 to 1.0. Changes in most cases are asymmetrical, bilateral.

Reduction of visual acuity is usually noted in the second stage, when cysts are ruptured. As a result of resorption and displacement of the contents of the cyst, a picture of pseudohydroponium is formed. Subretinal hemorrhages and the formation of the subretinal neovascular membrane are possible, ruptures and detachments of the retina are very rare, with the development of choroidal sclerosis.

The diagnosis is based on the results of ophthalmoscopy, fluorescent angiography, electroretinography and electrooculography. Assistance in diagnosis can be made by examining other members of the network. There is no pathogenetically grounded treatment. In the case of the formation of the subretinal neovascular membrane, laser photocoagulation can be performed.

Vitelliform macular degeneration of adults. Unlike Best's disease, changes develop in adulthood, are smaller and do not progress.

Stargardt's disease and yellow-spotted fundus (yellow-spotted dystrophy). Stragardt's disease is the degeneration of the macular area of the retina, which begins in the pigment epithelium and manifests itself as a bilateral decrease in visual acuity at the age of 8 to 16 years.

In the macular region, motility appears, and the focus is formed by a "metallic luster". The disease was described by K. Stargardt as early as the beginning of the 20th century. As a hereditary disease of the macular region with polymorphic ophthalmoscopic picture, which includes "broken bronze", "bull's eye", atrophy of the choroid, etc. The phenomenon of "bull's eye" is ophthalmoscopically visible as a dark center surrounded by a wide ring of hypopigmentation, which is usually followed by a ring of hypermentation. There is a rare form of yellow-spotted dystrophy without changes in the macular area. In this case, between the macula and the equator, multiple yellowish spots of various shapes are seen: rounded, oval, elongated, which can merge or settle separately from each other. Over time, the color, shape and size of these spots can vary. In all patients with Stargardt's disease, relative or absolute central scotomas of different sizes are revealed depending on the distribution of the process. With yellow-spotted dystrophy, the field of vision can be normal in the absence of changes in the macular area.

Most patients have a change in color vision according to the type of deuteranopia, red-green dyschromasia, etc. With yellow-spotted dystrophy, color vision can be normal.

There is no pathogenetically grounded treatment. It is recommended to wear sunglasses to prevent the damaging effect of light.

Yellow-spotted dystrophy Francescetti is characterized by the presence of yellowish foci in the posterior pole of the fundus. Their shape is diverse, ranging from point to 1.5 diameter of the optic disc. Sometimes the disease is combined with Stargardt's dystrophy.

Involutional dystrophies of the retina have two forms: nonexudative ("dry") and exudative ("wet"). The disease occurs in persons older than 40 years. It is associated with involuntary changes in the Bruch's membrane, the choroid and the outer layers of the retina. Gradually, foci of dyspigmentation and hyperpigmentation are formed due to the death of cells of pigment epithelium and photocontractors. Disruption of the processes of retinal release from the constantly updated outer segments of photoreceptors leads to the formation of drusen-foci of accumulation of the products of the exchange of the retina. Exudative form of the disease is associated with the appearance in the macular region of the subretinal neovascular membrane. Newly formed vessels that grow through the cracks in the Bruch membrane from the choroid to the retina, give repeated hemorrhages, are sources of lipoprotein deposits on the fundus. Gradually, the membrane is scarring. At this stage of the disease, visual acuity is significantly reduced.

In baking large with this pathology use antioxidant drugs, angioprotectors, anticoagulants. In exudative form, conducts laserocoagulation of the subretinal neovascular membrane.

Hereditary generalized retinal dystrophy

Photoreceptor dystrophies of the retina differ in the type of inheritance, the nature of the impairment of visual functions and the picture of the fundus depending on the primary localization of the pathological process in various structures: the Bruch membrane, retinal pigment epithelium, pigment epithelium complex - photoreceptors, photoreceptors and internal layers of the retina. The retinal dystrophy of both central and peripheral localization may be a consequence of the mutation of the gene of rhodopsin and perifyrin. At the same time, a symptom that unites these diseases is a stationary night blindness.

To date, 11 chromosomal regions are known that contain genes whose mutations are the cause of the development of retinitis pigmentosa, and for each genetic type of pigment retinitis, allelic and non-allelic varieties are characteristic.

Hereditary peripheral dystrophies of the retina In these forms of retinal dystrophy, the optically inactive part of the retina near the dentate line is affected. Not only the retina and the choroid, but also the vitreous are often involved in the pathological process, in connection with which they are called "peripheral vitreochorioretinal dystrophies."

Hereditary central retinal dystrophy

The central (macular) dystrophies of the retina are diseases localized in the central retina that are characterized by a progressive course, a typical ophthalmoscopic picture, and have similar functional symptoms: a decrease in central vision, a violation of color vision, and a reduction in the cone components of the ERG.

The inherited most common retinal dystrophies with changes in pigment epithelium and photoreceptors include Stargardt's disease, yellow-spotted fundus, Vitelliform dystrophy of Best. Another form of macular degeneration of the retina is characterized by changes in the Bruch's membrane and retinal pigment epithelium: the dominant druses of the Bruch's membrane, the sorcery dystrophy, macular degeneration that is associated with age, and other diseases.

[1], [2]