Diabetic retinopathy

Diabetic retinopathy (DR) is a sight threatening complication of systemic diabetes mellitus that results from damage to the blood vessels of the retina.

Diabetes mellitus affects 200 million people worldwide and the incidence appears to be increasing throughout the world, at least in part due to the increasing incidence of obesity and sedentary lifestyle. It is projected that from 2005 to 2050, the number of persons with DR will approximately triple. Diabetes is recognized as the leading cause of new blindness among adults aged 25-74 years in the Western world and responsible for 12% of all cases of blindness. Two of every 100,000 individuals in the general population become blind because of DR every year. An increased risk of DR appears to exist in Native Americans, Hispanics, and African Americans. Male and females seem to be equally affected, though slight male preponderance has been noted. Approximately 50% of people with diabetes have some degree of DR.

Nearly all patients with type 1 diabetes (younger-onset patients) and more than 60% of patients with type 2 diabetes (older-onset patients) develop retinopathy during the first two decades of disease, and approximately 4% and 2% of these patients respectively, become legally blind (defined as visual acuity of 1/20). Retinopathy is already present at the time of diagnosis in 20% of patients with type 2 diabetes. In the younger-onset group, approximately 90% of blindness is attributable to DR. In the older-onset group, in which other eye diseases may be present, one-third of the cases of legal blindness are due to DR.