Eye Disorders: Macular Degeneration
Macular degeneration is a deterioration of the macula. The macula is a small area of the retina in the back of the eye responsible for sharp, central vision. The macular vision allows people to drive, read, recognize faces, watch TV, and perform other tasks needing sharp vision straight ahead. Macular degeneration does not cause side vision loss or complete blindness. Therefore, even in advanced macular degeneration, ability to navigate around one's house and other environments is possible. In most situations, people with macular degeneration can take care of themselves with simple modifications to stoves, telephones, washing machines, etc.
Macular degeneration is a leading cause of vision loss. The most common type is "age-related," meaning it occurs in the elderly. The cause is thought to be due to a combination of genetic and environmental factors that leads to cell loss in the macula. Not every person will get macular degeneration, so it is not considered "normal aging" (like a cataract).
What are dry and wet macular degeneration?
There are two important types of age-related macular degeneration: dry and wet.
1. The dry form, which is the most common, is characterized by gradual photoreceptor cell death in the macular area. Slow central vision loss spanning years or decades is the rule.
2. The wet form, which is less common, is characterized by bleeding or leaking of abnormal blood vessels under the macula, which can produce a rather sudden (days to weeks) severe drop in vision. The dry form can become wet at any time.
Can macular degeneration be prevented?
There are no therapies that can prevent macular degeneration at this time. However, several steps can likely reduce one's risk. The first is to take good care of one's general health, especially high blood pressure. Second, a diet rich in antioxidant vitamins (like green leafy vegetables and darkly colored fruit) may help. Third, don't smoke. Finally, limiting the amount of UV light that enters your eye may reduce your risk. 100% UV blocking sunglasses and a hat with a visor are two effective ways to limit your UV exposure.
How is age-related macular degeneration treated?
The Age-Related Eye Disease Study (AREDS) showed that certain antioxidant vitamins slow the progression of moderate to severe macular degeneration. The vitamins are Beta-Carotene (a subtype of Vit A), Vit E, Vit C, and Zinc (taken with Copper). These vitamins are frequently recommended, and be taken along with a multivitamin. If there is a past or current history of smoking, consider avoiding beta-carotene because of an increased risk of lung cancer. Consult with your doctor about which vitamins to take, since too much of certain vitamins, especially vit. E, can be harmful.
It is important that patients monitor the vision daily in each eye with an Amsler Grid, which is available from your doctor. The purpose is to detect a sudden change that may be a sign of wet macular degeneration. The success of therapies for wet degeneration is proportional to how quickly it is discovered.
Several therapies are availabe for wet macular degeneration. These include several types of laser treatments as will as injectable medicines called "VEGF inhibitors," which tell the abnormal blood vessels to regress. Which therapy is best depends on the specific clinical situation. The therapies are usually administered by a retina specialist.
More information on this condition can be found at the National Eye Institute's website