Health Watch -- Blindness Causes (Part 1)

Health Watch is a Public Service of the Office of News and Publications and is intended to provide general information only and should not replace the advice of a medical professional. You should contact your physician if you have questions about any of these topics.

Your chances of going blind increase as you age, and the cause of the blindness may depend on your race.

If you're white, you're most likely to lose your eyesight to age-related macular degeneration as you get older. If you're African American, the most likely blindness causes are cataracts and glaucoma - and you're about three times more likely to go blind than white people in your age group. That's what researchers at Johns Hopkins University found in a recent study. About 1 percent of Americans over the age of 40 are blind, and that percentage is expected to increase as the population ages.

In the study, about half of the white adults who became blind lost their eyesight to age-related macular degeneration, or AMD. Doctors at UT Southwestern Medical Center at Dallas say that by the age of 75, about 30 percent of all Americans will have some degree of macular degeneration. The macula is an area in the center of the retina where light is focused and changed to nerve signals to create the images we perceive as sight. Macular vision allows people to do things that require sharp, straight-ahead vision, like reading and driving.

Dr. Albert Edwards, a UT Southwestern ophthalmologist, is studying the genetics behind macular degeneration. He says people with a family history of the disease have a much greater risk of developing it themselves. Other risk factors include smoking, early menopause, high blood pressure and heart disease, excess sun exposure and a diet high in certain kinds of fats.


May 2004