By Duke Medicine News and Communications

DURHAM, N.C. - - If you're 55 or older, checking for age-related macular degeneration (AMD) should be part of your annual eye exam.

As we age, most of us experience problems with our vision. In most cases, eyeglasses can correct the problem. However, 800,000 people are diagnosed each year with age-related macular degeneration, a condition that, in its most serious form, can lead to significant vision problems, says Michael J. Cooney, M.D., director of the Center for Macular Degeneration at Duke University Medical Center.

"Macular degeneration is an aging disorder of the macula, which is the part of the retina responsible for central, straight-ahead vision," he says. "There are two types of macular degeneration, the dry form and the wet form. Ninety percent of AMD cases are of the generally asymptomatic dry form, but one in 10 is the far more serious wet form."

In the dry form, according to Cooney, little aging changes accumulate underneath the retina, sort of like seeing gray hair or wrinkles.

"These little aging changes usually do not affect the vision, but they can weaken the retina and set the stage for the development of the wet form of macular degeneration," Cooney explains. "In this form, blood vessels start to grow among these little aging changes, into areas where they're not supposed to be. These blood vessels can bleed and cause scar tissue to accumulate, resulting in severe central vision loss."

Cooney says AMD is most often a problem for people in their late 50s and 60s.

"If someone does notice changes from the development of the wet form, one might begin to notice some distortion in their central vision or some blank spots in their central vision," he says.

He adds that some patients with wet AMD are treated today with a laser procedure called photodynamic therapy. Recent evidence also supports the position that high-dose antioxidant vitamins can slow the progression of AMD.

"It's important for patients to understand three things," says Cooney. "First, AMD affects the central vision and does not cause complete blindness; second, all patients over age 55 should have an annual dilated eye exam to look for signs of AMD; and third, treatments are now available for most AMD patients."