Peripheral retinal dystrophy is a disease characterized by thinning of the inner lining of the eye in the peripheral parts. For a long time, the pathology has an asymptomatic course. With a pronounced lesion of the retina, “flies” appear in front of the eyes, the function of peripheral vision is impaired. Diagnostics includes ophthalmoscopy, perimetry, ultrasound of the eye, visometry and refractometry. At the initial manifestations of dystrophy, conservative therapy (angioprotectors, antiplatelet agents, antihypoxants) is indicated. Pronounced degenerative changes require surgical tactics (laser coagulation in the affected areas of the retina).
Peripheral retinal dystrophy is a common pathology in modern ophthalmology. In the period from 1991 to 2010, the number of patients increased by 18.2%. In 50-55% of cases, the disease develops in people with refractive errors, among them 40% are patients with myopia. The probability of dystrophic changes with normal visual acuity is 2-5%. The first symptoms of pathology can occur at any age. Nosology occurs with the same frequency among males and females, but men are most predisposed to lattice dystrophy, which is due to the genetic features of inheritance.
Pathology can develop in persons with myopic or hypermetropic type of refraction, less often – in the absence of visual impairment. Patients with myopia are more at risk. The etiology of the disease is not fully understood. Lattice dystrophy is inherited by the X-linked type. Other main causes of retinal dystrophy:
- Inflammatory eye diseases. Local retinal lesions caused by a prolonged course of retinitis or chorioretinitis are the basis of degenerative-dystrophic changes in the peripheral parts of the shell.
- Violation of local blood supply. Regional changes in blood flow lead to trophic disorders and thinning of the inner shell of the eyeball. Predisposing factors are arterial hypertension, atherosclerotic vascular lesion.
- Traumatic injuries. Severe traumatic brain injury and damage to the bone walls of the eye socket leads to peripheral dystrophy.
- Iatrogenic effect. Changes in the inner shell develop after vitreoretinal operations or exceeding the power of exposure during laser coagulation of the retina.
The trigger factor for the development of peripheral dystrophy is disorders of local hemodynamics. The peripheral parts of the shell are most sensitive to lack of oxygen. With prolonged trophic disorder, the retina becomes thinner along the periphery, which is often unnoticeable when examining the fundus. The first manifestations occur against the background of infectious diseases, intoxication or diabetes in the decompensation stage. The myopic type of refraction potentiates the progression of dystrophy. This is due to the fact that with an increase in the longitudinal axis of the eyeball, the inner shell of the eye also lends itself to slight stretching, which leads to even greater thinning along the periphery. A certain role in the mechanism of development of the disease is assigned to degenerative changes of the vitreous body, in which traction and secondary damage to the retina occur.
Depending on the morphological picture, pathology is classified into lattice, frost-like and racemose types. Some variants of dystrophic changes in appearance resemble a “snail trail” and a “cobblestone pavement”. From a clinical point of view , the following forms of the disease are distinguished:
- Peripheral chorioretinal dystrophy. In this variant of nosology, the retina and choroid are involved in the pathological process.
- Peripheral vitreochorioretinal dystrophy. It is characterized by a lesion of the vitreous body, the retina and the vascular membrane.
Classification of vitreochorioretinal dystrophies by localization:
- Equatorial. This is the most common area of retinal lesion, because the thinning area is located along the circumference of the eye in the frontal plane.
- Paraoral. In this type, dystrophic changes are localized at the toothed line.
- Mixed. The shape is associated with the greatest risk of rupture due to the presence of diffuse changes over the entire surface of the retina.
For a long time, the lesion of the retina proceeds without clinical manifestations. The pathology is characterized by a decrease in peripheral vision, which leads to a difficult orientation in space. Due to the fact that the field of vision narrows along the concentric type, patients can only perform certain types of visual work (reading, drawing). The function of central vision, provided there are no refractive errors, does not suffer. In rare cases, patients complain about the appearance of floating flies in front of their eyes or defects in the visual field in the form of cattle. Symptoms such as “lightning” or flashes of bright light indicate a rupture of the retina and require immediate intervention. Peripheral dystrophy is characterized by a one-sided course, but with the lattice variant, both eyes are affected in most cases.
The most common complication of peripheral dystrophy is retinal rupture. Damage to the inner shell occurs in areas of greatest thinning when exposed to factors such as vibration, immersion under water, intense physical exertion. The vitreous body is often fixed to the edge of dystrophy, which leads to additional traction. Patients with changes in the periphery of the retina also have a high risk of retinal detachment. Patients are more prone to hemorrhages in the vitreous cavity, less often in the anterior chamber of the eye.
Due to the fact that this pathology is often characterized by an asymptomatic course, a thorough examination of the patient plays a leading role in the diagnosis. To visualize dystrophy along the periphery of the retina, the following ophthalmological studies are necessary:
- Ophthalmoscopy. The lesion zone with a lattice shape and dystrophy of the “snail trace” type is localized in the upper-outer quadrant at the equator of the eye. Due to the areas of vascular obliteration, dark and light spots are formed on the retina, resembling a lattice, or broken lines, which are called “snail tracks”. Frost-like dystrophy has the form of yellow-white inclusions located above the surface of the retina.
- Perimetry. The technique allows you to identify a concentric narrowing of the visual fields. If it is suspected that the patient has initial manifestations of the disease, it is recommended to use a quantitative method of perimetry.
- Visometry. The study makes it possible to diagnose normal central vision against the background of a decrease in peripheral vision. Visual acuity decreases in case of pathology on the background of myopia.
- Refractometry. The technique is used to study clinical refraction in order to identify patients at risk.
- Ultrasound of the eyes. Allows you to visualize the initial manifestations of pathology. With small-cystic dystrophy, multiple rounded formations of different diameters are determined. Ultrasound is used to diagnose changes in the vitreous body, identify adhesions and traction, and assess the size of the longitudinal axis of the eye.
Treatment of peripheral retinal dystrophy
The choice of therapeutic tactics depends on the nature of the pathology. Before starting treatment, the fundus is examined under conditions of maximum mydriasis. To eliminate the manifestations of peripheral dystrophy , apply:
- Conservative therapy. It is used only for the diagnosis of minimal manifestations of the disease. Oral administration of medications from the group of antiplatelet agents, angioprotectors and antihypoxants is indicated for patients. Bioactive additives, vitamins of group C, B are used as auxiliary preparations.
- Surgical intervention. Surgical treatment of the peripheral form of the disease is reduced to laser coagulation of blood vessels in the areas of greatest thinning. The purpose of the intervention is to prevent possible ruptures. The operation is performed on an outpatient basis. In the postoperative period, conservative therapy is necessary, including metabolic agents, antihypoxants and angioprotectors.
Prognosis and prevention
The prognosis for life and visual functions is favorable. Patients from the risk group need to be examined by an ophthalmologist 1-2 times a year, as well as when new symptoms of pathology appear. Non-specific preventive measures are reduced to the control of blood glucose, arterial and intraocular pressure. With myopic refraction, correction of visual acuity with glasses or contact lenses is necessary. Identification of objective signs of dystrophy in a patient requires the exclusion of extreme sports, heavy physical exertion.