Retinopathy that occurs as a result of diabetes is called diabetic retinopathy. There are two main forms of diabetes: insulin dependent diabetes mellitus (IDDM) and non-insulin dependent diabetes mellitus (NIDDM). Both forms of the disease result in elevated blood glucose levels. The increased levels of glucose damage blood vessels, and diabetic retinopathy damages the tiny blood vessels of the retina.
Nonproliferative retinopathy is an earlier stage of the disease during which the blood vessels of the retina bleed and leak other fluids. People in this stage of the disease may not notice any vision loss. During the more advanced stage of the disease, called proliferative retinopathy, more bleeding and leakage of fluids occurs, as well as the growth of new, abnormal, capillaries. These new capillaries are weak and also tend to bleed, bulge, or become blocked. It is during this stage that sudden and severe vision loss may occur.
It is very important to undergo a complete eye exam very soon after being diagnosed with diabetes, particularly NIDDM. Tight control of blood sugar levels is very effective at slowing the progression of diabetic retinopathy, especially during its early stages. Laser photocoagulation may be used to seal off and destroy the abnormal blood vessels that grow during the proliferative stage of the disease. This does not restore vision loss but can prevent vision from becoming worse.