Image borrowed from the National Institute of Health.
Macular degeneration is a disease of the retina in which the visual receptors begin to break down. The portion of the retina that is specifically effected with macular degeneration is called the macula. The macula is very densely packed with visual receptor cells and, therefore, allows for the seeing of fine details. When these cells begin to break down, sharp, central vision becomes difficult.
There are two forms of macular degeneration, dry and wet. The dry form of macular degeneration involves the simple breakdown of visual receptor cells. No treatment is currently availabe for this version, however, AREDS approved vitamins high in vitamin E, zinc, and beta carotene has been shown to decrease the rate of progression of the disease from a mild or moderate form to the more visual damaging severe versions of the disease. The wet form of macular degeneration involves the formation of leaky, blood vessels within the macula. These vessels leak blood within the macula further damaging the tissue, resulting in much worse vision. Laser and injection treatment options are available for the wet version of the disease.
The exact reason that these cells break down is still being investigated. Although the exact cause of this disease is not fullly understood, certain risk factors such as history of smoking, family history, and excessive ultra-violet light exposure. Yearly eye examinations and at home monitoring with an amsler grid are vital in monitoring the progress of macular degeneration.