What is the difference between wet and dry macular degeneration?
There are two forms of age-related macular degeneration: dry AMD and wet AMD. In dry AMD the cells of the macula slowly begin to break down. Dry AMD is diagnosed in 85 percent of macular degeneration cases. Both eyes are usually affected by dry AMD, although one eye can lose vision while the other eye appears unaffected. Drusen, yellow deposits under the retina, are a common early sign of dry AMD. The risk of developing advanced dry AMD or wet AMD increases as the number or size of the drusen increases. Dry AMD can advance and cause loss of vision without turning into the wet form of the disease; however, it is also possible for early-stage dry AMD to suddenly change into the wet form. Wet AMD, although it only accounts for 15 percent of the cases, results in 90 percent of the blindness; there is no early or intermediate stage of wet AMD. Wet AMD is caused by abnormal fragile blood vessels growing behind the macula which leak fluid and blood causing rapid damage to the macula.
