Definition:
Age-related macular degeneration (AMD) is one of the most common causes of poor vision after age 60. AMD is a deterioration or breakdown of the macula. The macula is a small area at the center of the retina in the back of the eye that allows us to see fine details clearly and perform activities such as reading and driving.

The visual symptoms of AMD involve loss of central vision. While peripheral (side) vision is unaffected, one loses the sharp, straight-ahead vision necessary for driving, reading, recognizing faces, and looking at detail.

Although the specific cause is unknown, AMD seems to be part of aging. While age is associated with developing AMD, heredity, blue eyes, high blood pressure, cardiovascular disease, and smoking have also been identified as risk factors. AMD accounts for 90 percent of new legal blindness in the US.

Types of AMD:
9 out of 10 people with AMD have the dry form (called atrophic), which results in thinning of the macula. Dry AMD takes many years to develop. Currently there is no treatment for this form of AMD.

The wet form of AMD (called exudative) is less common (occurring in 1 out of 10 people with AMD), but is more serious. In the wet form, abnormal blood vessels may grow in a layer beneath the retina, leaking fluid and blood. This creates distortion or a large blind spot in the center of vision. If the blood vessels are not growing directly beneath the macula, laser surgery is the only proven effective treatment, to date, for wet AMD. The procedure usually does not improve vision but prevents further loss of vision.

For wet AMD patients whose blood vessels are growing directly under macular center, a procedure called photodynamic therapy (PDT) may be used with fewer visual side effects than other treatments.