Spokane Eye Clinic

Macular Degeneration

What is the Macula?
The macula is the most central portion of the retina, directly opposite the lens. It is where the greatest number of light sensitive cells, called cones, are located. Cones are the cells which allow us to see color and fine detail. The high concentration of cones in the macula gives people extremely detailed and rich central vision.

What is Macular Degeneration?
When the light sensing cells (cones) in the macula gradually stop working and eventually die, it is called macular degeneration. This disease occurs most often in people over the age of 60, in which case it is called age related macular degeneration (ARMD). Less common are several hereditary forms of macular degeneration which affect children or teen-agers. Collectively, these diseases are called Juvenile Macular Degeneration, and include Best’s Disease, Stargardt’s Disease, Sorsby’s Disease, and some others.

Macular degeneration alone does not result in total blindness. While some activities like reading and driving a car become difficult and nearly impossible, there is no need to fear descending into complete darkness, tripping over furniture, running into walls, or needing to carry a white cane. Most patients continue to have some useful vision and are able to carry on many of their usual everyday activities with some aid from low vision devices.

What are the Symptoms of Macular Degeneration?
The principal symptom of macular degeneration is a reduction or loss of central vision, with retention of peripheral vision. Macular degeneration makes close and detailed work, like reading or threading a needle, difficult. In some cases, colors will begin to look dim, straight lines will appear to be distorted, and a dark or empty area appears in the center of vision.

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 (between 85 and 90%) of patients have "dry" macular degeneration. It is caused by aging and thinning of the tissues of the macula. Vision loss is usually gradual.

The remainder of cases of macular degeneration are "wet," so called because of leakage of blood and fluids into the retina from newly formed blood vessels in the area behind the retina. Usually, blood vessels behind the retina carry nutrients to, and waste products from, the retina. Sometimes, though, these fine blood cells begin to proliferate or multiply in a process called neovascularization. The newly created blood vessels then begin to leak into the retina, damaging and killing the cells of the macula. The cause of the sudden proliferation of these vessels is currently unknown.

Treatment of Macular Degeneration
While there is not yet a way to prevent or reverse the effects of macular degeneration, there are some things that can slow the progress of macular degeneration, and some things that can help the patient deal with their slowly degrading eye sight.

Treatment of the more common "dry" macular degeneration focuses mainly on helping the patient to find ways of coping with visual impairment. Since a patient’s peripheral vision is unaffected by macular degeneration, the remaining sight can be used to good advantage. Low vision devices, like magnifying devices, closed-circuit television, large-print reading materials, and talking or computerized devices, can help people to continue with many of their favorite activities. A wide range of support services and rehabilitation programs are also available in most communities.

In the case of "wet" macular degeneration, it is sometimes possible for the doctor to treat the problem in its early stages with laser surgery. The doctor uses a highly focused beam of light to seal the leaking blood vessels that damage the macula. This procedure can slow the rate of vision loss, but cannot halt macular degeneration. Laser surgery also leaves a small, permanently dark "blind spot" at the point of each laser contact. Overall, the procedure can preserve more sight than it damages, and can slow the progress of macular degeneration, but is not a cure.

Some doctors believe a special diet may slow macular degeneration. Although no conclusive scientific evidence has shown this belief to be true, a slightly modified diet, including a greater intake of dark green, leafy vegetables like spinach, collard greens, and kale, can hardly hurt. There is no need, however, to begin eating a Popeye sized portion of spinach per day. There has been nothing to show that massive doses of the nutrients provided by these vegetables can slow macular degeneration any more or less than 3 or 4 normal sized servings in a week.

There has been a great deal of discussion (and very little in the way of convincing research) among doctors about the role of vitamins and minerals in the treatment of age related macular degeneration. Many believe that the daily use of a combination of antioxidant vitamins and zinc will reduce he likelihood of progression of macular degeneration in an eye that starts out only mildly affected. Despite the lack of any convincing proof of effectiveness, taking vitamins after receiving the news that you have the early stages of macular degeneration is unlikely to do any harm. The commonly available vitamin and mineral pills made specifically for the eyes are Ivite, Ocuvite, OcuCaps, and ICAPS. These are over the counter preparations that require no prescription. Be sure you do not take more than one or two of these pills per day. There is certainly no evidence that more is better in this case.

Please note, though, that some vitamins and minerals can be harmful to certain parts of your body when taken in fairly large doses. Be sure to follow the directions on the packaging when taking any pill and to heed any warnings that may be applicable to you. If you are at the age where pregnancy is still a concern, discontinue use of these pills in favor of supplements suggested by your obstetrician when pregnant. The effects of these doses of vitamins on the fetus are not well worked out. If you have severe heart or kidney disease and still want to embark on this treatment, consult with your internist first.