These changes of the blood vessels in the eye occur to varying degrees as a person ages. The function of the retina is to act like a powerful computer that processes the images that we see. Just like a computer, it needs a very steady power supply. Any change in this power supply can alter its ability to function. The blood vessels underlying the retina serve as its primary power supply.
Macular degeneration is a major cause of blindness and visual impairment in the United States.
AMD currently affects an estimated 15 million Americans, including approximately one-quarter of all people over the age of 70. It is the leading cause of functional blindness in the industrialized world and the most common cause of legal blindness in people over the age of 50. What causes macular degeneration and how it specifically develops are currently not well understood, but ongoing research shows promise. Dry macular degeneration, which represents about 80 percent of all cases, is characterized by decreased vision in the presence of protein and fatty deposits called drusen that form between the retina and its primary blood supply. Wet macular degeneration, the most severe form of AMD, can produce severe loss of central vision within days or months.