What is Macular Degeneration?

Macular degeneration (ARMD) is a major public health issue–the leading cause of vision loss in Americans over age 65. ARMD is an aging change of the retina.

The eye is like a camera, with the retina as the "film." The eye’s optical parts (cornea and lens) focus images of the outside world on the retina. At the center of the retina is the macula, which provides the sharp vision needed for reading and recognizing faces.

As we get older some people develop liver spots and other aging changes on the skin. Likewise, people can develop aging spots on the retina. These aging spots on the retina are called drusen. They become more common as people get older. By age 65, about 5 percent of people have evidence of macular degeneration. By age 85, the incidence increases to 20 percent. In addition to the drusen, people can also develop pigmented spots and/or atrophic areas in the retina.

There are two types of macular degeneration - dry (atrophic) and wet (exudative). These are not two different conditions, but two different stages of the same condition. Dry ARMD refers to the earlier stage where drusen and atrophic areas are present. In about 10 percent of ARMD patients, the weak areas lead to abnormal blood vessel growth beneath the retina. These abnormal blood vessels – called choroidal neovascularization (abbreviated CNV or CNVM) – can bleed or leak. This results in blood and fluid accumulating beneath the retina – and is then referred to as wet macular degeneration.

Dry macular degeneration can sometimes lead to significant vision loss, but milder visual symptoms are more likely. More severe vision loss is usually due to wet macular degeneration. That’s why the wet form is considered a more serious or advanced stage. Still, even with wet macular degeneration, complete vision loss is very, very unlikely. But patients who lose central vision may be unable to drive, read and perform other tasks that require sharp vision. However, they almost always maintain peripheral vision. This usually allows them to walk around without assistance and perform other activities that do not require sharp central vision.

A common misconception is that macular degeneration always results in blindness. Not true. Many people do suffer significant vision loss from macular degeneration - but many more people with dry macular degeneration have little or no visual trouble.