Age-related macular degeneration (AMD) is a disease that affects the macula, the central part of the retina. AMD is the most common cause of vision loss in people over age 60, and it affects more than 10 million Americans. If you have macular degeneration, the center of your vision is affected, so people rarely go completely blind from the disease. However, macular degeneration can make detailed tasks, such as reading and driving, identifying faces and recognizing colors very difficult. When AMD progresses, and some people experience significant central vision loss, although they may still retain some peripheral vision.
The macula is the center of the retina, the thin membrane of tissue at the back of your eye, and it contains many nerve cells. These cells transform light into signals that tell the brain what you are seeing. Macular degeneration causes these light sensitive cells within the macula to break down, so that less of the macula functions.
There are 2 forms of macular degeneration: dry and wet. Dry macular degeneration affects 90% of those with the disease and its cause is unknown. Slowly the light sensitive cells within the macula break down and less of the macula functions. Sufferers may notice that their vision is blurry or wavy.
Wet macular degeneration can cause severe vision loss. It occurs when new blood vessels under the retina start growing toward the macula. These new vessels tend to be fragile and often leak blood and fluid under the macula. This causes rapid damage and leads to central vision loss.
Doctors believe aging, heredity and environment all play a role in developing AMD. People over the age of 75 have a 30% risk of developing macular degeneration. Risk factors for AMD include a family history of the disease, poor diet and smoking, which doubles the risk of contracting AMD. Caucasians are much more likely than any other group to develop AMD.
Treatment of Dry Macular Degeneration
Currently, dry AMD cannot be treated. Your doctor may address early onset AMD with nutritional therapy. Eating a healthy diet high in antioxidants can help support macula cells. Your doctor may also suggest you take some supplements which may further support macular cell structure. New research in the field has shown high levels of antioxidants and zinc can lower the risk of advanced AMD by 25%. These same nutrients can also reduce the risk of vision loss by 19%. People who are at high risk for developing the advanced form of AMD should consider taking supplements as a preventative measure.
In other studies, Lutein and Zeaxanthin, which is a carotenoid plant substance that is found in the macular pigment, have also been linked to decreasing the risk of developing ARMD in the non-advanced form. These substances can be found naturally in dark green leafy vegetables and in dietary supplements. We advise a dilated eye examination and discussion with our doctors before choosing a dietary supplement to help identify your risk characteristics. Your family physician should also be contacted to insure these supplements will not interfere with other medications or systemic conditions you may have.
Treatment of Wet Macular Degeneration
The most common and clinically effective treatment for wet AMD is anti-VEGH therapy. Anti-VEGH therapy consists of a series of regular injections placed directly into the retina to help inhibit the formation of new blood vessels. Anti-VEGH therapy has helped preserve and, in some cases, reverse the damaging consequences of wet AMD. While there are some side effects, this treatment has been highly effective for many wet AMD patients.
Other wet AMD treatments include laser therapy to seal leaking blood vessels. Additionally, some cases of wet AMD can be treated with a procedure called Photodynamic Therapy (PDT) with Visudyne. This treatment involves injecting a dye called Visudyne into the bloodstream. This special drug is activated by a laser beam, which then causes the macular blood vessels to shrink. It is important to realize that any laser therapy is not a cure, but rather a treatment to help stop further vision loss. The risk of new blood vessels growing back is relatively high.