Diabetic retinopathy

Diabetes and the eye

Diabetes mellitus originates from a functional disorder of the pancreas. Two main types of this disease are differenciated. In the juvenile type I diabetes, insufficient insulin is produced in the pancreas. The type II diabetes, in contrast, mostly only originates at an older age. In this case, the insulin production can very well be sufficient, but the body is not able to use the insulin.

As a consequence of this metabolic disease, the smallest blood vessels in the entire organism change within the course of about 5 years. As a result, the feared late complications, such as renal deficiencies up to complete failure, damage of the nerves, premature arteriosclerosis originate. In addition, wound healing is delayed, and many diabetics suffer from "open" legs. Due to changes in the larger coronary vessels, often considerable cardiocirculatory problems occur. In the eye, diabetes results in a disease of the retina called diabetic retinopathy.

Diabetic retinopathy - a disastrous eye disease

This disease originates due to changes in the retinal vessels. On one hand, the vessels are occluded, on the other, also pouches of the small capillaries originate. In the further course, new vessels are formed pathologically, which grow from the retina into the vitreous. In this stage of diabetic retinopathy, vision is already seriously endangered. The pathologically proliferating vessels bleed into the vitreous and shift the visual axis. At the same time, cords may be formed which act like "tractile ropes" tearing the retina from its nourishing bed, the choroid. This form of diabetic retinal disease is called proliferative diabetic vitreoretinopathy. If its progress is not stopped, it inevitably leads to blindness.

The patient does not realize the changes disturbing his vision for a long time. To be able to treat retinal damage as early as possible, it is important that every diabetic is examined by an ophthalmologist at the very beginning of the disease and regularly thereafter. The examination required to detect diabetic retinopathy, its form and its stage does not exert any stress on the patient, as shown in fig. 1.

Basically, the following forms of ocular involvement are distinguished:

1. The fundus retinopathy in its mild, moderate or severe form, where vascular changes remain limited to the retina (fig. 2).

2. The even more severe advanced proliferative vitreoretinopathy with vascular proliferation and bleeding into the vitreous (fig. 3)

and, furthermore, independent of the two described changes, the diabetic maculopathy, i.e. hazard for the point of harpest vision in the center of the retina and degeneration of the central visual cells.

Diabetes and the eye - a complex problem

Especially in the adjusting phase with insulin, considerable fluctuations of vision may occur, e.g. as transient short-sightedness. Therefore, driving a car should be avoided during this period. As a general rule: Carefully observe your eyes!

Treatment of the diabetic retinopathy

The earlier vascular changes are diagnosed and treated by the ophthalmologist, the less aggressive is the required treatment.
Today it is possible to prevent a progress of the vascular changes with the practically painless laser coagulation in not too advanced stages of the diabetic retinopathy (fig. 4).

In severe forms, the advances of vitreoretinal surgery mostly allow to save these eyes from complete blindness with a complicated operation (fig. 5).

This immediate measure is all the more important taking into account that in many cases it is not known for how long the diabetic metabolic disease has already existed.

* Before diabetic changes of the fundus occur, control examinations by an ophthalmologist under pupil dilation are required at least once a year

* If changes in the retinal vessels already exist, the patients must be examined by an ophthalmologist at much shorter intervals - according to the stage of the disease every 3 to 6 months.

Today, advanced therapeutic methods are available to save the patient´s vision. However, only early diagnosis of diabetic changes of the eye can prevent blindness with a good chance of success.

Quellennachweis: © Copyright 2000 Berufsverbandes der Augenärzte Deutschlands (BVA) und Deutschen Ophthalmologischen Gesellschaft (DOG)