Loss of independence is one of the most difficult things people may face as they age, and one cause is vision loss due to age-related macular degeneration (AMD). This disease steals sight from millions of people, usually after age 55, but there are new treatments that preserve vision for many.
AMD is a progressive disease that destroys sight from the center of the visual field, leaving only very foggy central vision and clear peripheral vision. Obviously, tasks like reading and driving become impossible without a clear line of sight.
"We refer to AMD as dry, which is the initial form of the disease, and wet, which is the more debilitating form once the disease has progressed," explains Dr. Brent Davidson, an ophthalmologist on staff at SSM St. Clare Health Center. "We can diagnose AMD in the dry stage, when people can still see fairly well. The key is to prevent the disease from progressing —Â it cannot be cured or reversed."
People diagnosed with dry AMD have small, round, fatty deposits, called drusen, in the central portion of the retina, which is known as the macula. As drusen accumulate, the macula thins, and abnormal blood vessels may begin to form. These vessels may leak blood under the retina, causing rapid vision loss.
"As with other diseases, prevention is the primary goal," Dr. Davidson explains. "We don't have definitive data on what causes AMD, but we do know that being tobacco-free and eating a low-fat diet rich in antioxidants, like vitamins C and E, as well as beta-carotene and zinc, may help prevent or delay AMD. We also believe diets high in omega-3 fatty acids may be beneficial. Additionally, sun exposure may increase risk, so it's important to protect the eyes with polarized sunglasses."
Having regular eye exams after age 40 will help ensure that if signs of AMD develop, the disease can be monitored and treated. If the disease progresses to the wet form, most patients can be treated with an injectable drug, Lucentis or Avastin. Studies indicate that the drug may halt progression of the disease for as long as two years and can even restore a degree of lost vision. The drug inhibits the growth of the abnormal, leaky blood vessels.
"At this point, we're very optimistic that treatments with drugs like Lucentis will help manage wet AMD and allow people to retain their vision," Dr. Davidson says. "Patients may need injections as often as monthly, but most consider it a small price to pay for their eyesight."
In the world of medicine, it's a good day when we can report real progress against a disease like AMD. Take care of yourself, get regular eye exams as recommended by your doctor, and enjoy your sight throughout your life.
Dr. Tim Pratt, board-certified in internal medicine and geriatrics, serves as chief medical officer at SSM St. Clare Health Center, 1015 Bowles Ave. in Fenton. For a referral to any SSM St. Clare physician, call 1-866-SSM-DOCS (1-866-776-3627) or visit ssmstclare.com.
