Macular Degeneration

What is macular degeneration?

Macular degeneration is a deterioration or breakdown of the macula. The macula is a small area in the retina at the back of the eye that allows you to see fine details clearly and perform activities such as reading and driving. When the macula doesn't function correctly, your central vision can be affected by blurriness, dark areas or distortion. Macular degeneration affects your ability to see near and far, and can make some activities--like threading a needle or reading--difficult or impossible.

Although macular degeneration reduces vision in the central part of the retina, it does not affect the eye's side or peripheral vision. For example, you could see the outline of a clock but not be able to tell what time it is.

Macular degeneration alone does not result in total blindness. Even in more advanced cases, people continue to have some useful vision and are often able to take care of themselves. In many cases, macular degeneration's impact on your vision can be minimal.

What causes macular degeneration?

Many older people develop macular degeneration as part of the body's natural aging process. There are different kinds of macular problems, but the most common is age-related macular degeneration. Exactly why it develops is not known, and no treatment has been uniformly effective. Macular degeneration is the leading cause of severe vision loss in people over 65.

"Dry" macular degeneration (atrophic)--Most people have the "dry form of macular degeneration. It is caused by aging and thinning of the tissues of the macula. Vision loss is usually gradual.

"Wet" macular degeneration (exudative)--The "wet" form of macular degeneration accounts for about 10% of all macular degeneration cases. It results when abnormal blood vessels form underneath the retina at the back of the eye. These new blood vessels leak fluid or blood and blur central vision. Vision loss may be rapid and severe.

What are the symptoms of macular degeneration?

Macular degeneration can cause different symptoms in different people. The condition may be hardly noticeable in its early stages. Sometimes only one eye loses vision while the other eye continues to see well for many years. But when both eyes are affected, the loss of central vision may be noticed more quickly. Following are some common ways vision loss is detected:

• words on a page look blurred
• a dark or empty area appears in the center of vision
• straight lines look distorted

How is macular degeneration diagnosed?

Many people do not realize that they have a macular problem until blurred vision becomes obvious. Your ophthalmologist can detect early stages of macular degeneration during a medical eye examination that includes the following:

• a simple vision test in which you look at a chart that resembles graph paper
• viewing the macula with an ophthalmoscope
• sometimes special photographs of the eye, called fluorescein angiographs, are taken to find abnormal blood vessels under the retina. Fluorescent dye is injected into a vein in your arm and your eye is photographed as the dye passes through the blood vessels in the back of the eye.

How is macular degeneration treated?

Despite ongoing medical research, there is no cure yet for "dry" macular degeneration. Some doctors believe that nutritional supplements may slow macular degeneration, although this has not yet been proven. Treatment of this condition focuses on helping a person find ways to cope with visual impairment.