Macular degeneration describes a wide variety of eye conditions which alter the sharpest and most acute central vision. It can affect people of all age, but is most often a problem that develops in late adulthood. The macula is a small area in the back of the eye consisting of highly concentrated light absorbing nerve cells. (See Diagram at Left.)
The best way to understand the macular area in relation to the total area of the retina is to imagine the placing of a dinner plate in the center of the floor of a large room. It is this very small region, the macula, that provides the most acute vision as well as color perception. When vision is checked on a standard eye chart, it is only the function of this tiny area that is measured. The remainder of the retina provides peripheral vision, which mainly detects motion. When the macula deteriorates, blurring and distortion of central vision results.
Changes in the macula include deposits of toxic materials, growth of abnormal new vessels under the macula, occurrences of hemorrhages through leakage from the new vessels, detachment of the retina, formation of holes in the macula and the growth of membranes in and over the macula. All of these conditions cause deterioration of central vision. Macular degeneration does not result in total blindness, since normal peripheral vision permits most patients to lead independent lives. The loss of the ability to read can often be helped with a variety of visual aids now available.
There are two main types of age-related macular degeneration: the atrophic type ("dry") (See Diagram at Left) and the disciform type ("wet"). Laser treatment and new microsurgical techniques may be of use in some cases of the "wet" form of this disease. Early detection of any changes in vision, such as blurring, difficulty in reading and distortion of straight lines, is important to the success of treatment. Because the progress of macular degeneration is slow and irreversible, regular eye examinations after the age of 50 are very important. Much research is being pursued to understand and formulate methods of treatment for this important eye disease. A recent national study has demonstrated that certain vitamin combinations can slow progression of the retinal changes.