Age-related macular degeneration (AMD) is an eye disease causing poor vision in more than 10 million older Americans. The retina is the inner layer of the eye that captures light and turns it intoelectrical signals. When these electrical signals arereceived by the brain through the optic nerve, they are translated into images. The most sensitive part of the retina is the macula, the area responsible for sharp, detailed central vision that allows you to read, recognize faces, and drive. With AMD, this sharp central vision is lost, but peripheral (side) vision is preserved. This Patient Page is based on one previously published in the May 24/31, 2006, issue of JAMA.
Risk factors for AMD include older age, white race, a family history of AMDand smoking. There are 2 types of AMD, dry and wet. Dry AMD is more common, causing about 90% of AMD. The macula slowly breaks down because of the accumulation of small yellow deposits called drusen. It can develop so gradually that you might not notice changes in vision at first. Wet AMD is less common (about 10% of cases) but is more severe and may progress more rapidly. Wet AMD is caused by a leakage of blood and fluid behind the retina due to abnormal blood vessels. Dry AMD can turn into wet AMD.
One symptom of early wet AMD is that straight lines appear wavy. Blind spots or blurriness may develop near your central field of vision. Other symptoms include difficulty adjusting to low light and a decrease in the intensity of colors.
It is important to have regular eye examinations after age 50 years, even if you don'thave any symptoms. If you have AMD in one eye, your other eye may be compensating so that you don't notice any change in vision. Your doctor can give you an Amsler grid test (looks like graph paper with thick lines). If the lines start to look wavy, this may be a sign of wet AMD and you should see your eye doctor immediately.
Develop healthy habits, like quitting smoking (if you now smoke), exercising, maintaining normal blood pressure and cholesterol, and eating a healthy diet. People who eat fish and green leafy vegetables may be at lower risk of AMD. There is no treatment for early dry AMD, although a special combination of supplements (zinc and antioxidant vitamins) may slow progression in some people with more advanced disease. Recent advances in the treatment of wet AMD involve injection of medicines into the eye that can cause regression (shrinkage) of the abnormal blood vessels, improving vision. These treatments are usually effective and are now widely used. They have largely replaced the older treatment of laser therapy to the macula, which can also destroy abnormal blood vessels.
National Eye Institute www.nei.nih.gov/health /maculardegen/armd_facts.asp
Mayo Clinic www.mayoclinic.com/health/macular-degeneration/DS00284
Agency for Healthcare Research and Quality guideline.gov/content.aspx?id =14275
American Academy of Ophthalmology www.geteyesmart.org/eyesmart/diseases/amd.cfm
To find this and previous JAMA Patient Pages, go to the Patient Page link on JAMA 's website at www.jama.com. Many are available in English and Spanish.
This article was corrected for errors on November 26, 2012.
Goodman DM, Parmet S, Lynm C, Livingston EH. Age-Related Macular Degeneration. JAMA. 2012;308(16):1702. doi:10.1001/jama.2012.4091