The macula is a small but vital part of the retina. The macula is responsible for your central vision. When you read, thread a needle, or perform any other activity that requires you to see fine details, you are using your macula. When the macula does not function as it should, objects appear distorted, blurry or may seem to disappear. Macular degeneration reduces central vision but generally does not affect peripheral vision or cause total blindness.
Age-related macular degeneration is the leading cause of severe vision loss in the United States. About 1 in 10 Americans between 66 and 74 years of age has macular degeneration and this increases to 30% of those older than 75. The majority of patients with this disease have the “dry” version of this disease. These patients experience thinning of the tissues of the macula and the accumulation of abnormal deposits called drusen underneath the retina. Vision loss in this form tends to be gradual. Patients with many and large drusen are at increased risk of severe visual loss and development of the “wet” form of the disease. Wet macular degeneration affects one in ten patients with macular degeneration. It accounts for the majority of cases of blindness from this disease. Abnormal blood vessels form and leak fluid and blood into the macula and can cause sudden swelling and severe vision loss.
Macular degeneration is a complex disease with a strong hereditary component. Aside from genetic factors (over which we have no control), smoking is the strongest risk factor for the development of macular degeneration. Studies have shown that 25% of patients with severe vision loss from macular degeneration are smokers. Avoiding smoking is critical for patients with macular degeneration and their family members.
The Age-Related Eye Disease Study (AREDS 2) showed that patients with moderate macular degeneration in at least one eye benefited from vitamin supplements by a reduction in the rate of progression of the disease by about 25%. Patients with mild macular degeneration and family members without the disease did not show any benefit from this intervention when it was taken for an average of six years.
The best way to increase your antioxidant intake is through dietary sources. A minimum of 5 servings of the following vegetables per week (especially the dark green leafy vegetables (members of the cabbage family, mustard greens, spinach and collards) were shown to decrease the onset of macular degeneration.
Vitamin C: spinach, mustard greens, collards, red and green peppers, cabbages, turnips, citrus fruits, cantaloupe, kiwi
Vitamin E: seeds, nuts and whole wheat grains
Zinc: oysters, fish, pumpkin seeds, ginger root, pecans, Brazil nuts
Copper: Brazil nuts, almonds, hazelnuts, walnuts, pecans
Lutein: Kale, collards, spinach, parsley, celery, leeks, broccoli
Wet macular degeneration has been treated since 2005 with injections of chemicals that block vascular endothelial growth factor (VEGF). These medications have revolutionized the treatment of this disease by preventing the growth of abnormal blood vessels. Around 90% of treated patients maintain their vision while 40% experience an improvement in their vision. Unfortunately, these medications often require repeated injections as frequently as every four weeks to maintain these results.
Research is continuing to produce more effective and longer lasting treatments but we do not have a cure. Many people with macular degeneration will still experience vision loss. Most activities can be continued by using a variety of low-vision devices, including magnifiers, large print materials and electronic or talking aides.