People with diabetes are nearly twice as likely to develop glaucoma as other adults. Cataract and glaucoma also affect many people who do not have diabetes. The NEI estimates that of the approximately 10.5 million Americans who have diagnosed diabetes, between 40-45 percent have some degree of diabetic retinopathy. Between 600,000-700,000 Americans have diabetic retinopathy severe enough to cause vision loss. As many as 24,000 people go blind from this disorder annually, making it a leading cause of blindness among working-age Americans.
Diabetic retinopathy is a complex disease.
Although scientists understand much about the disease's natural history, they are still unclear about its specific pathological causes. There is, however, a consensus that diabetic retinopathy probably does not stem from a single retinal change. Rather, the disease may be triggered by a combination of biochemical, metabolic, and hematologic abnormalities. A chronic increase in normal blood-glucose levels may gradually alter cell metabolism in the retinal blood vessels. Blood platelet abnormalities.