How can macular disease affect eyesight?
There are two basic types of age-related macular degeneration (AMD): the dry type, which affects 90 percent of patients, and the wet type, which affects 10 percent. In the dry type, the macular tissue slowly begins to malfunction. The hallmark of this dry form of AMD is “drusen,” which are yellow age spots in the macula. The reasons for this malfunction are not yet understood. The rate of visual loss is variable, with some people maintaining reading vision and good distance vision for years. Unfortunately, there is, as yet, no treatment. In wet type AMD, blood vessels from the choroid grow through cracks in the barrier filter, which separates the retina and choroid. These abnormal vessels, which spread out under the macula, are referred to as a “choroidal neovascularization (CNV),” or a “net.” AMD is the most common cause of CNV. Leakage or bleeding from these abnormal vessels is what causes visual loss. Another frequent cause of subretinal neovascular membranes is severe myopia (nears
