Age-Related Macular Degeneration (AMD)Macular degeneration is the most common cause of legal blindness in developed countries and affects up to 1 in 10 patients over the age of 60 in the United States. Macular degeneration affects the central portion of the retina, the layer of tissue which detects light and lines the inner surface of the eye (similar to the film of a camera). As the disease progresses, the central portion of the retina is damaged, and results in a decrease in the central vision (see simulated photo,below).
Simulation of the distorted central vision of a patient with macular degeneration.
Damage to the retina can be seen by your eye doctor in the form of yellowish deposits in the retina (drusen) in the early form of the disease and by atrophy (or cell death) as the macular degeneration progresses.
Picture of the retina of a patient with macular degeneration. Notice the yellowish deposits (drusen) in the center of the picture.
About 10% of patients develop blood vessel growth (neovascularization) underneath the retina, which can lead to a precipitous drop in vision. This is called the "wet" form of AMD. In some of these patients, the use of a laser to destroy the abnormal blood vessels can help stabilize the vision.
The vast majority of patients with macular degeneration have the "dry" form of AMD, in which the progression of disease is slow and is related to a gradual cellular death in the central retina (atrophy). Until recently, there was no scientifically proven treatment for these patients. However, a recent study (the Age-Related Eye Disease Study, or AREDS) funded by the National Eye Institute revealed that daily supplementation with vitamins A, C, E, and zinc delayed the progression of macular degeneration. Specifically, almost 4000 patients with mild, intermediate, or advanced AMD were enrolled in the study and followed for an average of more than 6 years. Patients were randomly assigned to receive daily oral tablets containing 1) high doses of antioxidants (vitamins A, C, and E); 2) zinc; 3) antioxidants plus zinc; or 4) placebo. In patients with intermediate or advanced forms of macular degeneration, supplementation with antioxidants plus zinc decreased their risk for advancement by 25% over the follow-up period! More details of the results of this study can be seen here.
Based on this study, Boulder Eye Surgeons recommends that all patients with intermediate or advanced forms of macular degeneration take oral vitamin and zinc supplementation at the dosages used in the study (see below). Bausch and Lomb provided the vitamins used in the study and a new product, Ocuvite® PreserVision™, supplies the exact vitamin formulation used in the AREDS study.
Other brands can be used, but be sure that they contain the following vitamins and zinc in the dosages indicated: vitamin C, 500 mg; vitamin E, 400 IU; beta carotene, 15mg; zinc, 80 mg, as zinc oxide; and copper, 2 mg, as cupric oxide. Smokers should be careful taking high dosages of vitamin A, as some studies have shown this to increase mortality rates.
You can monitor your central vision for the progression of macular degeneration using an Amsler grid (see below). A rapid change in the central distortion of your vision may indicate the "wet" form of macular degeneration (see above) which may be amenable to laser treatment. The Amsler grid test consists of a grid of lines. The grid should be held about 12 inches from the eyes and each eye should be tested independently. While looking at the central dot with each eye separately, be sure that you can see all four corners of the grid. If not, or if any of the lines are blurry, wavy, distorted, bent, gray, or missing, you should call Boulder Eye Surgeons to have your eyes examined. We recommend using the grid at least once a week. You can remind yourself of this by placing the grid in a convenient place (i.e. on the refrigerator door or bathroom mirror). Use the grid below to take the test on your computer screen. Or, you can download the black-on-white version for printing.