Macular degeneration is a group of diseases characterized by a breakdown of the macula. The macula is a small area at the back of the eye that allows us to see fine details clearly. When the macula doesn't function correctly, we experience blurring or darkness in the center of our vision. Macular degeneration affects both distance and close vision and can make some activities - like reading or threading a needle - difficult or impossible.

The macula is the center portion of the retina that makes central vision and visual acuity possible

Although macular degeneration reduces vision in the central part of the retina, it does not effect 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 can cause different symptoms in different people. Sometime only one eye loses vision while the other eye continues to see clearly for many years.

The 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 as in the diagram above.

What causes macular degeneration?

Many older people develop macular degeneration as part of the body's natural aging process. The two most common types of age-related macular degeneration are "dry" (atrophic) and "wet" (exudative).
Most people have "dry" macular degeneration. It is caused by aging and thinning of the tissues of the macula. Vision loss is usually gradual. "Wet" macular degeneration accounts for about 10% of all cases. It results when abnormal blood vessels form 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.

How is macular degeneration diagnosed?
Many people do not realize that they have macular problems until blurred vision becomes obvious. Your ophthalmologist (Eye M.D.) can detect early stages of macular degeneration during a medical eye exam that includes the following:

• Viewing the macula with an ophthalmoscope;
• A simple vision test in which you look at an Amsler grid;
• Sometimes special photographs, called angiograms, are taken to find abnormal blood vessels under the retina.

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. Treatment of this condition focuses on helping a person find a way to cope with visual impairment.
In its early stages "wet" macular degeneration can be treated with laser surgery, a brief and usually painless outpatient procedure. Laser surgery uses a highly focused beam of light to seal the blood vessels that damage the macula. Although a small permanently dark "blind spot" is left at the point of laser contact, the procedure can preserve more sight overall.

Testing your vision with the Amsler grid
You can check your vision daily by using the Amsler grid like the one pictured below. You may find changes in your vision that you wouldn't notice otherwise. Putting the grid on your refrigerator is a good way to remember to look at it each day.
To use the grid:

1. Wear your reading glasses and hold the grid at 12-15" in good light.
2. Cover one eye.
3. While looking directly at the center dot, not whether all lines of the grid are straight or if any areas are distorted, blurred or dark.
4. Repeat this procedure with the other eye.
5. If any area of the grid looks wavy, blurred or dark contact your ophthalmologist immediately.
   

Amsler Grid