FAMILY MEDICINE® COLUMN
By John C. Wolf, D.O.
Associate Professor of Family Medicine®
Ohio University College of Osteopathic Medicine

NO TREATMENT CAN RESTORE SIGHT LOST TO DIABETIC EYE DISEASE

Question: I recently heard the last few minutes of a radio program about an eye disease they called diabetic retinopathy. My uncle has diabetes, so I asked him about this condition. He didn't know anything about it. What is diabetic retinopathy?

Answer: Diabetic retinopathy is a disease of the small blood vessels known as capillaries that supply the retina the light sensitive part of the eye with oxygen and other nutrients. It is a serious complication of diabetes that is the most common cause of blindness for individuals with this disease.

I've always found the blood vessels in the eye especially interesting to study because they are the only ones that can be easily observed. Your doctor observes these blood vessels when he or she looks through your pupil with that lighted instrument called an ophthalmoscope. During such an examination, changes suggestive of diabetic eye disease abnormal blood vessels and small leaks that show up as tiny areas of red bleeding can be seen.

While the observation of these changes is quite direct and relatively easy, the explanation of the exact mechanism that causes them is not. Metabolic changes that lead to a relative lack of oxygen in the retina seem to play a pivotal role. Researchers have also determined the small leaks take place in-between the cells that form the walls of the vessel. Exactly how this occurs is not clear. It is clear that the end result of this process is a poor supply of nutrients to the retina and also the development of new and ineffective small blood vessels. This new vessel formation is called "neovascularization" for those fans of doctor lingo.

The individual with diabetic retinopathy may experience no problems with vision until suddenly losing his or her sight. However, loss of vision usually begins in a small area of the visual field in one eye and can rapidly expand to damage most or all of the vision of that eye. In the worst cases, total blindness develops.

The likelihood of diabetic retinopathy increases with the length of time the person has diabetes and with the need for insulin to control the blood sugar. Studies have shown that somewhere between 20 to 50 percent of individuals with diabetes for 10 years will have diabetic retinopathy. Those who develop the disease before age 30 or those who must use insulin are at greatest risk.

Up to 20 percent of the diabetic population in the United States fail to seek care for their disease until retinopathy has developed. And, a study from the University of California, Los Angeles, showed 42.8 percent of black and Hispanic newly diagnosed diabetic individuals had suffered with their disease long enough to develop retinopathy before the diagnosis. The delay in identifying and treating diabetic retinopathy is a serious problem for these individuals and an equally serious and expensive problem for society.

Question: What can be done for diabetic retinopathy?

Answer: There are really only two effective treatments for this condition. Good control of the blood sugar and control of high blood pressure, if the individual also has this condition will reduce the risk of new retinal damaged. Laser treatments to seal off those leaky small vessels supplying the retina is the second treatment, and it will help preserve sight at its present level. No treatment is effective at restoring sight that has already been lost.

If you have diabetes, you should strive to keep your blood sugar within the normal range at all times. This reduces, but doesn't eliminate, the chance of developing retinopathy. Further, you should also have a yearly professional eye examination to search for the earliest signs of diabetic damage, since early laser treatment helps preserve good eyesight.

Family Medicine® is a weekly column. To submit questions, write to John C. Wolf, D.O., Ohio University College of Osteopathic Medicine, Grosvenor Hall, Athens, Ohio 45701.