Friday, March 9, 2001

K-STATE EXPERT DISCUSSES COMMON EYE DISEASE AFFECTING AGING POPULATION

MANHATTAN -- When you can't see well enough to jot down a grocery list, or to drive, you lose your independence.

Carol Ann Holcomb, Kansas State University associate professor of human nutrition, knows these challenges from her work researching age-related macular degeneration. She has studied both the physical and emotional changes in people who develop this disease.

According to Holcomb, age-related macular degeneration is a common eye disease that results in the loss of central vision. As a person ages, the risk of developing the problem increases. Twenty percent of people ages 65-74 and 35 percent of people ages 75-84 are at risk of developing some form of age-related macular degeneration. Data are limited for those over age 85.

"For the population 65 and over, age-related macular degeneration is the leading cause of visual impairment," she said. "The National Eye Institute predicts that by the year 2010, the disease will be more common than the two other eye diseases that affect the older population, diabetic retinopathy and glaucoma, combined."

Age-related macular degeneration occurs when the macula is damaged or deteriorates in one or both eyes. The macula, not much larger than a capital "O" on a typewriter, is a small region on the retina where light is focused.

"You need it to see fine details for everyday tasks such as writing, driving, reading and sewing," she said.

There are two types of age-related macular degeneration -- "dry" and "wet." About 90 percent of people who are diagnosed with macular changes have the dry form. With the dry form, the light-sensing cells in the eye break down and the tissue thins. Vision loss is gradual and painless.

"Early signs are the increased time it takes to adapt to light/dark environments, blurred vision and increased sensitivity to glare," Holcomb said.

About 10 percent of people with the dry form will progress to the wet form. New blood vessels develop in the macula in an effort to supply blood and nutrients to the thinning tissue and damaged light-sensing cells. These new blood vessels are fragile and often leak blood and fluid, resulting in a greater and more rapid loss of central vision.

"There will be a very rapid loss of the ability to read or to recognize another person's face, to drive, to do anything that involves detailed vision straight ahead. If your vision is changing rapidly, for example if you're looking at a telephone pole and instead of that pole being straight, it's wavy, it means that there's some hemorrhaging occurring."

Hemorrhaging can be stopped in only 15 to 20 percent of the cases, and only after a series of treatments, she said.

"They can use what they call a photo coagulation process -- they use a laser beam to seal off those blood vessels so they don't leak," Holcomb said. "Unfortunately, after a series of treatments, it may leave scar tissue that further damages a person's eye sight."

While the disease causes a loss primarily in central vision -- a person can still see peripherally -- complete blindness is not associated with age-related macular degeneration. However, a person may meet the criteria for legal blindness and receive services from programs designed for people with low vision.

Holcomb said making lifestyle changes can help ease the psychological changes in people with the disease. Learning to use sharp color contrasts -- a white cup for coffee or a light plate with dark foods, for example, and using talking devices such as clocks and modifying furniture placements all can help ease the psychological effects.

"Right now, the levels of depression, discouragement and embarrassment are very high," she said. "People were embarrassed by spilling things, having to ask for help and not being able to use their favorite recipes," she said. "Adapting your lifestyle early on can help you deal with having it."

Unless something is discovered to prevent this disease, low-vision will continue as a major problem for older adults, Holcomb said.

"And it's not a pretty picture as far as what can and cannot be done right now," she said. Studies have shown certain foods may reduce a person's risk of developing age-related macular degeneration. Foods high in antioxidants, food sources of lutein, zeaxanthin, beta-carotene, Vitamin C, Vitamin E and zinc are recommended in addition to a low-fat diet.

According to Holcomb, there are other ways to reduce the risk of developing the disease, including having annual eye exams by professionals, protecting eyes from sunlight exposure by wearing a brimmed hat and sunglasses; eliminating smoking; controlling high blood pressure; and getting regular physical activity.

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Prepared by April Blackmon. For more information contact Carol Ann Holcomb at 785-532-0152.