What Is Macular Degeneration?


Macular degeneration (MD) is the leading cause of blindness for people older than 55 in the United States, and it affects more than 10 million Americans. Advanced MD affects one out of every 14 people ages 75 and older. Even with severe vision loss, those with this condition keep their peripheral (side) vision. With the help of low vision aids, people can lead full lives.

MD affects a small portion of the retina, a thin multi-layered structure that lines the inside back two-thirds of the eye. The retina consists of millions of visual cells that receive light and send electrical impulses through the optic nerve to the brain, resulting in sight. The macula is 100 times more sensitive to detail than the rest of the retina and contains most of the color-sensitive cells. But it is also much less sensitive to light. So if you need to see in the dark, look just to the side of what you want to see. The macula is most important for detailed vision such as reading, driving a car and recognizing faces.

The disease process

As a person ages, changes in the macula may cause problems with reading and other tasks that require good central vision. Scientists do not know why these changes occur, but aging plays a definite role in the process. Also, yellow pigments found in the macula (lutein and zeaxanthin) are thought to filter out visible blue light, which might damage the macula.

Most people with MD (85 percent to 90 percent) have a form of the disease that develops very slowly (the “dry” form). In this form, tiny yellowish deposits (called drusen) develop near the macula, and the layer of light-sensitive cells in the macula becomes thinner as some cells break down. These changes typically do not cause vision loss. But for some, objects may become dim or distorted, most noticeably when a person tries to read. If one eye had dry MD, the other eye usually has some signs of the condition as well.

A much greater threat to vision arises when the dry form of MD evolves into the “wet” (neovascular) form of the disease. In the wet form, new blood vessels grow beneath the macula. The vessels leak fluid and blood, causing the light-sensitive cells near them to die. This process produces a severe disturbance of vision: straight lines look wavy, and later on, blank areas may appear in the center of the field of vision. If the leakage and bleeding continue, much of the tissue in the macula may be killed or injured within a few weeks or months. In advanced MD, the center of the visual field is lost, causing a roughly circular area of blindness. This damage cannot be repaired, because the nerve cells of the macula do not grow back. Although only about 10 percent of people with MD develop the wet form of the disease, they make up the majority of those who experience serious visual loss from MD.

Coping With Macular Degeneratio

What devices are available?

Many useful devices (low vision aids) are available to help partially sighted people make the most of their remaining vision. These devices have special lenses or electronic systems that produce enlarged images of nearby objects. Magnifiers include spectacles, telescopes, hand or stand-alone magnifying glasses and closed-circuit television. Your eye care specialist can prescribe these devices and suggest further sources for you to contact regarding counseling, training and other special services.

Other useful devices include

  • Watches and timers with large numbers.
  • Special lamps to provide bright illumination for reading and close-up work.
  • Large-print books, newspapers and periodicals.
  • Large-print attachments for telephones.
  • Talking calculators and books.

How can you compensate?

Macular degeneration (MD) creates a blind spot directly ahead of you, which cannot be moved from the center of your vision. You cannot see through it, but you can see around it. Therefore, a useful trick is to look intentionally slightly off center, a little bit away from anything you want to see. This works especially well for looking at food on your plate, watching television or recognizing someone when you meet them. For example, turn the TV on and try looking at one of its corners. You will have to experiment to find the ideal place to look in any given situation, but you will be surprised at how much vision you have.

Psychological counseling may help you deal with the depression and frustration that often accompany vision loss.

Legal protection

The Americans with Disabilities Act (ADA) gives civil rights protections to individuals with disabilities by guaranteeing equal opportunity in public accommodations, employment, transportation, state and local government services, and telecommunications. The ADA defines a person with a disability as someone who: 1) has a physical or mental impairment that substantially limits one or more of major life activities; 2) has a record of such an impairment; or 3) is regarded as having such an impairment. Major life activities are those an average person can perform with little or no difficulty, such as walking, speaking, breathing, performing manual tasks, seeing, hearing, learning, caring for oneself and working.

MD is a physical disorder that can impair your vision. If you are diagnosed with the disease, you may meet one or more of the ADA criteria for disability. If you suffer from impaired vision caused by macular degeneration, the ADA can protect you from discrimination by an employer because of your impairment. For further information, contact the Equal Employment Opportunity Commission (EEOC) at 1-800-669-EEOC (voice) or 1-800-800-3302 (TDD), or write to the EEOC Office of Communications and Legislative Affairs, 1801 L St. N.W., Washington, D.C. 20507.

Discrimination

If you think you have suffered discrimination because of your diagnosis of macular degeneration, you should consult a lawyer who specializes in disability law to learn if you are qualified for protection under the ADA.

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