There are two groups of these disorders, those that affect the young and those that affect the old. Age related Macular Degeneration (AMD) usually affects people over the age of 50 and there are two distinct types - "wet" AMD and "dry" AMD. "Wet" AMD results from the growth of new blood vessels in the choroid, causing an accumulation of fluid in the macula which leads to retinal damage. This type of degeneration can often be successfully arrested by laser surgery.

"Dry" AMD represents at least 80% of all AMD cases and results in atrophy of the Retina. Usually yellowish-white round spots called drusen first appear in a scattered pattern deep in the macula. Later degeneration of both the Pigment Epithelium and the cones begins. While AMD is not inherited in a predictable way, heredity may be involved to some extent. Juvenile inherited macular degeneration occurs much less frequently. One type of this disorder is Best Disease (Vitelliform Dystrophy) an autosomal dominant disorder that is usually diagnosed at quite a young age.

Another is Stargardt Disease which is an autosomal recessive condition that causes atrophy in the macula. All these conditions affect the central vision often causing blurring of vision, distortion of lines and shapes, blind spots and an increasing difficulty in reading and recognising faces. Side or peripheral vision is usually not affected and so mobility remains good. Additional information about Macular Degeneration is available from the Foundation.