The Natural History of Diabetic Retinopathy

Diabetic retinopathy is a common and increasing cause of blindness. The higher incidence of retinopathy is related to the longer survival of the diabetic patient. The etiology of diabetic retinopathy remains unknown. However, two varieties appear to exist: Type I retinopathy, characterized by a slowly progressive course and ophthalmoscopic findings of microaneurysms, round hemorrhages, and waxy exudates; and Type II retinopathy, associated with a more rapid loss of vision, in which the main findings are venous engorgement, vascular proliferation, connective tissue condensation, and recurrent vitreous hemorrhages. Both types may result in retinitis proliferans and blindness. In the proliferative (Type II) diabetic retinopathy, regression of the vascular element, but not the fibrous tissue, may occur spontaneously or after hypophysectomy