Diabetes is the leading cause of blindness in working age adults in America. Blindness occurs due to diabetic retinopathy, a disease of the blood vessels and the delicate nerve layer called the retina within the eye. Diabetic retinopathy is divided into two forms: Non-proliferative (NPDR) and Proliferative (PDR) retinopathy. In NPDR, retinal vessels become "leaky", spilling fluid and blood into the retina, thus "water-logging" the retina and failing to supply the nutrients necessary for its good health. PDR is characterized by changes of NPDR and new abnormal blood vessels which always leak and bleed if left untreated. About 40% of diabetics will develop PDR over a 15 year span.

The most common cause of decreased vision in diabetes is NPDR of the central retina, called the macula. Such a leakage is very difficult to treat but with focal applications of laser light to seal the damaged vessels, vision may preserved and occasionally even improved. PDR poses a very serious threat to vision as well: When detected, new abnormal blood vessels should be treated with extensive laser therapy. Untreated PDR often progresses to retinal detachment with eventual irreversible and complete blindness.

Close control of diabetes helps reduce risks of retinopathy. Regular exams are critical for early detection and treatment of diabetic retinopathy. All diabetics should be evaluated annually, even if they have no visual symptoms.

Raj U. Dugel, M.D.
Diplomate, American Board of Ophthalmology
Member, South Bay Independent Physicians Medical Group, Inc.