Tracking a Vision Thief
Science still searches for the cause of sight-robbing AMD.
Searching for a Cause and a Cure
Scientists are working to better understand the disease in the hope of discovering ways to prevent and better treat it.
Eating modified dietary fats, such as partially hydrogenated vegetable oil, along with exposure to environmental pollution such as cigarette smoke may play a role, Mogk believes. "We are seeing the first generation [of those] who have lived their whole lives since we've been pumping the environment full of chemicals," Mogk says.
Studies in the October 9, 1996 issue of the Journal of the American Medical Association partially support her theory. Researchers found smokers are two to three times more likely to develop AMD.
According to Mogk, avoiding cigarettes, modified fats (because they can be deposited in the retina), and exposure to blue light (the wavelength just above ultraviolet) might help minimize the risk of getting AMD. (Orange, yellow, or amber-tinted lenses can block blue light.)
Several current studies, including one conducted by the NEI, are focusing on the possible preventive effects of antioxidants, such as vitamins A and E. Studies so far have yielded conflicting findings.
Other scientists are looking to foods that contain the same pigments found in the retina, says Jeff Blumberg, Ph.D., aresearcher at Tufts University in Boston. "[These pigments] filter out wavelengths of light that can damage the retina," Blumberg says. He is studying the body's ability to use lutein and zeaxanthin, pigments that are found in eggs, corn, and spinach.
According to a study he conducted, published in the August 1999 issue of the American Journal of Clinical Nutrition, lutein and zeaxanthin are absorbed more efficiently from egg yolks than from the vegetable sources. "The important thing is that we've identified these nutrients in the diet," he says. "When levels in the blood go up, the density of the pigment in the retina goes up."
The next step, to prove that consuming certain foods can prevent macular degeneration, will require another 10 or 15 years, Blumberg says.