Macular degeneration is the leading cause of central vision loss for people over age 60 and is often referred to as age-related macular degeneration. Currently, more than 2 million people have been diagnosed with this disease, and the number of cases is increasing each year. Macular degeneration occurs when a portion of the central retina, a nerve tissue at the back of the eye which senses light, is damaged. Early detection is important as treatment can delay the severity of vision loss.

Types

There are two forms of macular degeneration; the "dry" form and the "wet" form. Most people have the "dry" form of the disease, which is characterized by yellow deposits, called drusen, which form on the macula, the central portion of the retina. While drusen do not cause vision damage directly, as they grow in size or number they can dim or distort vision, a symptom many people notice while reading or trying to distinguish details. As "dry" form advances the light sensitive area of the macula thins, leading to atrophy of the tissue and eventually tissue death. Patients in the atrophic stage may notice blind spots in their vision. In later advanced stages, central vision may be lost.

"Wet" form macular degeneration is characterized by the growth of blood vessels underneath the macula. Blood and fluid from these vessels leak into the eye causing visual distortions that make straight lines look wavy and produce blind spots. These abnormal blood vessels eventually scar, leading to permanent loss of central vision. Approximately 10 percent of people diagnosed with macular degeneration will develop the "wet" form of the disease.

Symptoms

The symptoms of macular degeneration are sometimes not recognized until the disease effects both eyes. The first sign of the disorder is often the visual distortion of straight lines. Other symptoms may include dark, blurry areas in the center of vision or white spots in the same area. You may also notice a change in the way you perceive colors as the ability to distinguish them diminishes.

Treatment

Treatment can help prevent severe vision loss and slow the progression of the disease. Current treatment includes vitamin supplements and the use of low vision aids, which produce enlarged images of objects.

Two types of laser therapy are currently available for individuals with "wet" form macular degeneration: general and photodynamic laser therapy. General laser therapy uses high-energy light to destroy abnormally growing blood vessels. Photodynamic laser therapy is a two-step process in which a light sensitive drug is absorbed by the blood stream and a cold laser is used to activate it, destroying the abnormal blood vessels.

Sources:
www.webmd.com
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