The peripheral zone of the retina is practically invisible in the usual standard examination of the fundus. But it is precisely at the periphery of the retina that dystrophic (degenerative) processes often develop, which are dangerous because they can lead to tears and retinal detachment. Changes in the periphery of the fundus – peripheral dystrophies of the retina – can occur in both short-sighted and far-sighted people, and in individuals with normal vision.
Possible causes of peripheral retinal dystrophy
The causes of peripheral dystrophic changes in the retina are not fully understood. Dystrophy can occur at any age, with the same probability in men and women.
There are many possible predisposing factors: hereditary, myopia of any degree, inflammatory eye diseases, craniocerebral and eye injuries. Common diseases: hypertension, atherosclerosis, diabetes, intoxication, past infections.
The leading role in the occurrence of the disease is given to impaired blood supply to peripheral areas of the retina. The deterioration of blood flow leads to metabolic disorders in the retina and the appearance of local functionally modified areas in which the retina is thinned. Under the action of physical exertion, work associated with lifting to a height or immersion under water, acceleration, transfer of weights, vibration, ruptures can occur in dystrophically modified areas.
However, it has been proven that in people with myopia, peripheral degenerative changes in the retina occur much more frequently, since with myopia, the length of the eye increases, resulting in stretching of its membranes and thinning of the retina in the periphery.
Peripheral chorioretinal dystrophies and Peripheral vitreochorioretinal dystrophies – what is the difference?
Peripheral retinal dystrophy is divided into peripheral chorioretinal dystrophies , when only the retina and the choroid are affected, and Peripheral vitreochorioretinal dystrophies – with involvement in the degenerative process of the vitreous body. There are other classifications of peripheral dystrophies, which are used by ophthalmologists, for example, by the localization of dystrophies or by the degree of danger of retinal detachment.
Some types of peripheral retinal dystrophy
► Lattice dystrophy – most often detected in patients with retinal detachment. It is assumed family-hereditary predisposition to this type of dystrophy with a greater frequency of occurrence in men. Usually found in both eyes. Most often localized in the upper outer fundus quadrant equatorial or anterior to the equator of the eye.
On examination of the fundus of the eye, lattice degeneration looks like a series of narrow white, as it were, fleecy stripes, forming figures resembling a lattice or a rope ladder. This is the way the obliterated retinal vessels look .
Between these altered vessels, pink-red foci of thinning of the retina, cysts and retinal breaks occur. Characteristic changes in pigmentation in the form of darker or lighter spots, pigmentation along the vessels. The vitreous body is fixed to the edges of dystrophy, i.e. “ tractions ” are formed – strands that pull the retina and easily lead to ruptures.
► Dystrophy of the “snail track” type. On the retina, whitish, slightly glittering, bar-shaped inclusions with the presence of many fine thinning and perforated defects are found. Degenerative foci merge to form tape-like zones, which in appearance resemble the trail from a snail. Most often located in the upper-outer quadrant. As a result of such dystrophy, large round gaps may form.
► Inepoid dystrophy is a hereditary disease of the periphery of the retina. Changes in the fundus, as a rule, bilateral and symmetrical. On the periphery of the retina there are large yellowish-white inclusions in the form of “snow flakes”, which protrude above the surface of the retina and are usually located near the thickened partially obliterated vessels, there may be pigment spots.
Inepodemic degeneration progresses over a long period of time and does not so often lead to ruptures like the lattice and the footprint of a snail.
► The “cobblestone” type of degeneration is located, as a rule, far on the periphery. Individual white foci are visible, of a slightly elongated shape, around which small clumps of pigment are sometimes identified . Most often found in the lower parts of the fundus, although it can be determined along the entire perimeter.
► Celiac disease ( small cystic ) degeneration of the retina is located at the extreme periphery of the fundus. Small cysts can merge, forming larger ones. During falls, blunt injuries, cysts can rupture, which can lead to the formation of perforated tears. When viewed from the eye of the day cysts look like multiple round or oval bright red formation.
► Retinoschisis – retinal dissection – can be congenital and acquired. Most often it is a hereditary pathology – a malformation of the retina. Congenital retinal cysts, X-chromosomal juvenile retinoschisis are congenital forms of retinosis , when patients, in addition to peripheral changes, often show dystrophic processes in the central zone of the retina, leading to reduced vision. Acquired dystrophic retinoschisis most often occurs with myopia, as well as in old and old age.
If there are also changes in the vitreous body, then often tractions (cords, adhesions) are formed between the modified vitreous and the retina . These adhesions, joining with one end to the thinned area of the retina, many times increase the risk of ruptures and subsequent retinal detachment.
By type of retinal breaks are divided into perforated, valve and type of dialysis. Holey tears most often result from lattice and carotid dystrophy, the opening in the retina gapes.
The valve is called the gap, when the retina covers the gap. Valvular tears are usually the result of vitreoretinal traction , which “pulls” the retina. When a rupture is formed, the area of vitreoretinal traction will be the tip of the valve.
Dialysis is a linear rupture of the retina along the dentate line — the point of attachment of the retina to the choroid. In most cases, dialysis is associated with blunt trauma to the eye.
The gap in the fundus look like bright red clearly delineated foci of various forms, through which a pattern of the choroid can be seen. Particularly noticeable retinal breaks on a gray background detachment.
Diagnosis of peripheral dystrophy and retinal tears
Peripheral retinal dystrophies are dangerous because they are practically asymptomatic. Most often they are found by chance during the inspection. If there are risk factors for detecting dystrophy, it can be the result of a thorough, targeted examination. There may be complaints about the appearance of lightning, flashes, the sudden appearance of more or less number of floating flies, which may already indicate a retinal break.
Full diagnostics of peripheral dystrophy and “silent” tears (without retinal detachment) is possible when examining the fundus of the eye in conditions of maximum medical expansion of the pupil with the help of a special three-mirror Goldman lens, which allows you to see the most extreme areas of the retina.
If necessary, the producing pressure of the sclera (sklerokompressiya) – the doctor as it pushes the retina from the periphery to the center, resulting in some inaccessible for inspection peripheral areas become visible.
Today, there are also special digital devices with which you can get a color image of the periphery of the retina and, in the presence of dystrophy zones and tears, estimate their size relative to the area of the entire fundus.
Peripheral Dystrophy Treatment and retinal breaks
In identifying peripheral dystrophy and retinal tears, treatment is carried out, the purpose of which is to prevent retinal detachment.
Perform prophylactic laser coagulation of the retina in the area of dystrophic changes or border laser coagulation around an existing gap. With the help of a special laser, an impact is made on the retina along the edge of a dystrophic focus or rupture, resulting in a “gluing” of the retina to the underlying eye shells at the points of exposure to laser radiation.
Laser coagulation is performed on an outpatient basis and is well tolerated by patients. It is necessary to take into account that the process of formation of adhesions takes some time, so after laser coagulation it is recommended to observe a gentle mode, eliminating hard physical labor, lifting to height, diving under water, exercises related to acceleration, vibration and sudden movements (running, parachuting , aerobics, etc.).
Speaking about prevention, first of all, they mean prevention of retinal breaks and retinal detachment. The main way to prevent these complications is the timely diagnosis of peripheral retinal dystrophy in patients at risk, followed by regular monitoring and, if necessary, preventive laser coagulation.
The prevention of terrible complications depends entirely on the discipline of patients and attention to their own health.
Patients with existing pathology of the retina and patients at risk should be examined 1 – 2 times a year. During pregnancy, it is necessary to inspect the fundus of the eye on the wide pupil at least twice – at the beginning and at the end of pregnancy. After delivery, an ophthalmologist examination is also recommended.
Prevention of the dystrophic processes themselves at the periphery of the retina is possible in members of the risk group – these are myopic, patients with hereditary predisposition, children born as a result of severe pregnancy and childbirth, patients with arterial hypertension, diabetes, vasculitisand other diseases for which there is worsening peripheral circulation.
Such people are also recommended regular preventive examinations by an ophthalmologist with examining the fundus in conditions of drug-induced pupil dilation and vascular and vitamin therapy courses in order to improve peripheral circulation and stimulate metabolic processes in the retina.The prevention of terrible complications, therefore, is entirely dependent on the discipline of patients and attention to their own health.