Age-related macular degeneration (AMD) is the most common cause of blindness in individuals age 65 and older in the western world. It results from a hardening of the arteries that nourish the retina affecting the macula, part of the retina that is responsible for clear vision. Deprived of oxygen and essential nutrients needed for the retina to function, the central vision deteriorates. In addition to age, other risk factors for AMD include female gender, a family history of AMD, fair complexion, cardiovascular disease, smoking and (possibly) sunlight exposure.
There are two types of AMD.
- Non-exudative (also known as dry AMD) is the most common form of the disease and has a better long-term visual prognosis than wet AMD.
- Exudative (also known as wet AMD) is associated with the development of new blood vessels that grow beneath the retina leading to bleeding, scarring and severe reduction in central vision.
Signs of macular degeneration include loss of central vision (either gradually or suddenly), difficulty reading or performing tasks that require the ability to see detail and/or distorted or wavy vision. Presently there is no cure for AMD. Most individuals with reduced central vision benefit from low vision rehabilitative therapy. Laser coagulation may be effective for some patients with wet AMD although the recurrence of new vessel growth following laser treatment is over 50%. Many experimental treatments are currently being tested for their effectiveness in treating macular degeneration. Some research also indicates the role of antioxidant vitamins and nutritional supplements may be helpful for the prevention of AMD in some patients.