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Macular Degeneration

What is Macular Degeneration?

Macular degeneration is damage or a breakdown of the macula of the eye. The macula is the small, central point of the light-sensing retina in the back of the eye. It processes the sharp central vision we use for reading and other fine tasks.

When the macula loses its ability to function fully, we experience blurriness, darkness, or other visual distortions in the center of our vision. This makes close work, such as reading or threading a needle, difficult or impossible for the unaided eye.

Although macular degeneration reduces vision in the central part of the retina, it does not affect the eye's peripheral vision--the ability of the eye to see objects to the side of the center. This means that macular degeneration alone does not result in total blindness.

What Causes Macular Degeneration?

Many people develop macular degeneration as part of the body's natural aging process. Less commonly, macular degeneration may be an inherited condition, as in the case of juvenile macular degeneration. Injury, infection, inflammation or extreme nearsightedness may also damage the delicate tissue of the macula.

The two most common types of age related macular degeneration are "dry" (atrophic) and "wet"(exudative).

"Dry" macular degeneration (also called atrophic or invilutional macular degeneration).

By far the most common type, "dry" macular degeneration is caused by aging and thinning of the tissues of the macula. Vision loss is usually gradual.

"Wet" macular degeneration (also called exudative or hemorrhaging macular degeneration).

Accounting for about 10% of all cases, "wet" macular degeneration results when abnormal blood vessels form at the back of the eye. These new blood vessels leak fluid and blood. Leaking fluid distorts and blurs central vision, often resulting in dense scar tissue in the macula. Vision loss may be rapid and severe.

What are the Symptoms of Macular Degeneration?

Macular degeneration can cause different symptoms in different people. Sometimes only one eye loses vision while the other eye continues to see well for many years. The condition may be hardly noticeable in its early stages. But when both eyes are affected, reading and close-up work can become difficult. You may experience one or more of the following symptoms:

• Colors look dim.

• Words on a page look blurred.

• Straight lines look distorted, especially at the center of vision.

• A dark or empty area appears in the center of the vision

How is Macular Degeneration Diagnosed?

Early detection of eye problems can lead to more effective treatment. Periodic eye examinations by an ophthalmologist should be a regular part of general health care to detect problems before they become serious. This is especially critical if you are over 50 or if your family has a history of retinal problems.

Many people do not realize that they have a macular problem until blurred vision becomes obvious. Yet ophthalmologists can detect earlier stages of macular degeneration through the following diagnostic procedures:

• Observation of the macula with an ophthalmoscope.

• A simple vision test in which the patient looks at a grid resembling graph paper to indicate the loss or distortion of vision.

• A color vision test.

• Sometimes an image called a fluorescein angiogram is used to detect abnormal blood vessels within the macula. In this procedure, the ophthalmologist injects a dye into the patients's arm. Circulation of the blood causes the dye to reach the eye, where the dye shows the exact location of blood vessels and any leakage. The ophthalmologist records this information by photographing the macula.

How is Macular Degeneration Treated?

Treatment of the more common "dry" or atrophic form of macular degeneration focuses on helping a person find ways to cope with the visual impairment. Despite ongoing medical research, there is no cure yet for the condition. Some doctors believe that nutritional supplements may slow the degeneration, although scientific evidence is preliminary.

Various low-vision optical devices--magnifying devices, closed-circuit television, large-print reading materials, and special lighting can help to minimize the effects of visual impairment. Your ophthalmologist can prescribe optical devices or refer you to a low-vision specialist or center. Because side vision is usually not affected, a person's remaining sight can be very useful. A wide range of support services, rehabilitation programs and devices are available to help people with macular degeneration continue with many of their favorite activities.

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