age-related macular degeneration atrophic macular degeneration true 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. dry macular degeneration geographic atrophy MedDRA:10067792 Dani Welter