Macular Degeneration – Part 1The most common cause of blindness in people over age 50, macular degeneration affects millions of Americans to varying degrees. The macula is the central and most light-sensitive portion of the retina, which is located at the back of the eye. It controls the central field of vision and the ability to distinguish color and fine detail. When macular degeneration occurs, these basic functions of eyesight begin to break down. Objects in a person's central viewing area--things being directly looked at--appear blurred, gray, or simply blank, even though peripheral vision remains normal. As the condition progresses, it threatens the patient's ability to read, drive, watch television, or recognize people easily. There are two forms of macular degeneration: "dry" and "wet," both of which are painless and usually affect one eye at a time. The dry, or age-related, form is so called because tiny bits of debris accumulate beneath the macula as it thins over time. Dry macular degeneration, which accounts for about 90% of cases, progresses slowly enough that most patients do not have serious loss of vision. In wet macular degeneration, new blood vessels develop under the retina and begin to push against it. The vessels can leak fluid, which is believed to cause scarring of the macula and result in permanent damage to central vision in a matter of days. Patients with dry macular degeneration may suddenly develop this fast-moving form. The principal damage in macular degeneration is probably caused by the unstable oxygen molecules called free radicals, which can be dangerous to many types of cells, not just those in the eyes. Environmental and lifestyle factors such as high dietary levels of saturated fat, tobacco smoke, and years of exposure to the sun's ultraviolet rays all encourage production of free radicals in the retina. Medical conditions such as high blood pressure, diabetes, and heart disease can also contribute to macular degeneration by restricting the supply of blood to the eye. Having light-colored eyes also increases the risk of macular degeneration, as does a family history of the disorder. In addition, advancing age magnifies all of these risk factors. About one-fourth of all Americans over age 65--a rapidly growing segment of the population--show some signs of macular degeneration, as do one-third of those over age 80. Next week, we will explore the natural nutrients to help prevent and improve macular degeneration. Be blessed and be healthy!
Ward W. Bond, Ph.D. |
