Age Related Macular Degeneration, or AMD, is the leading cause of blindness for those 65 years of age and older.
AMD is caused by a deterioration of the retina. The macula is the center of the retina, and provides the central vision necessary to read, drive, and recognize object.
“In the absence of effective treatment for AMD, the number of patients severely disabled by late-state AMD is expected to increase in the next 20 years by more than 50% to 3 million in the United States alone” (JAMA).
Causes
There are two types of Age-Related Macular Degeneration. Dry macular degeneration is more common, and results in yellow deposits on the macula that blurs the vision slowly. Wet macular degeneration is responsible for 15% of cases, and is a result of blood vessels under the macula leaking fluid. Wet AMD is severe and rapid, and causes straight lines to appear wavy and central vision to be degraded.
The causes of AMD are not entirely understood, and may be a collection of diseases. Oxidative stress has been identified as a cause of AMD, as it is with many age-related disorders. Oxygen concentration, exposure to light, and photosensitizers put the retina at risk for oxidative stress.
Risk Factors
Risk factors include increasing age, Caucasian race, and smoking.
A study from the Division of Preventive Medicine concluded “cigarette smoking increases the risk of AMD in a dose-dependent fashion.” Those who smoked one or more packs a day had a 2- to 3-fold increased risk of AMD compared with those who do not smoke. Unfortunately smokers of one or more packs a day also had a 40% to 80% excess risk of AMD with vision loss for years following smoking cessation. This is a particularly sobering statistic for a disease that has no cure.
Treatment for Macular Degeneration
There is no cure for AMD, but therapies exist to slow progression. Wet AMD can be treated with laser therapy to prevent leaking, however recurrences are common.
Frequent eye exams are necessary for those with AMD. A recent study found that zinc and antioxidant vitamins (C, E, and beta-carotene) reduce the risk and progression of AMD. Vitamin E is found in whole grains, vegetable oil, eggs, and nuts. Zinc is found in meat, poultry, fish, whole grains, and dairy. Beta carotene is found in carrots, kale, and spinach. Vitamin C is found in citrus fruits, green peppers, broccoli, and potatoes. The study found that these foods are more beneficial than nutritional supplements.