atrophic macular degeneration (EFO_1001492) can be described as follows. Dry AMD is most common type of macular degeneration and affects 90% of the people who have the condition. In the dry form, there is a breakdown or thinning of the layer of retinal pigment epithelial cells (RPE) in the macula. No medical or surgical treatment is available for this condition. Also known as: dry macular degeneration, geographic atrophy.