Thinner Choroid and Greater Drusen Extent in Retinal Angiomatous Proliferation Than in Typical Exudative Age-Related Macular Degeneration

PURPOSE: To compare choroidal thickness and extent and density of drusen between eyes with typical exudative age-related macular degeneration (AMD) and eyes with retinal angiomatous proliferation (RAP). DESIGN: Observational case series. METHODS: Twenty-four eyes with typical exudative AMD and 20 eyes with RAP were included. Subfoveal choroidal thickness was measured using enhanced depth imaging optical coherence tomography. Eyes were classified into 3 groups according to the extent of drusen distribution in the fundus photograph. Density of drusen was estimated based on optical coherence tomography images of the fellow eye. The proportion of the length beneath the drusen per the entire length of the Bruch membrane was defined as the density of drusen. Subfoveal choroidal thickness, extent of drusen distribution, and the density of drusen were compared between typical exudative AMD and RAP. RESULTS: Mean +/- standard deviation subfoveal choroidal thickness in eyes with typical exudative AMD and eyes with RAP was 184.9 +/- 68.5 pm and 139.0 +/- 65.5 mu m, respectively (P = .035). The mean density of drusen was 0.06 +/- 0.08 and 0.24 +/- 0.12, respectively (P < .001). In the typical exudative AMD group, 19, 3, and 2 eyes were included in the small extent group (< one third), intermediate extent group (one third to two thirds), and large extent group (> two thirds), respectively. In the RAP group, 3, 14, and 3 eyes were included in each aforementioned group, respectively (P = .001). CONCLUSIONS: The thinner subfoveal choroidal thickness and greater extent and density of drusen in RAP than the typical exudative AMD may suggest compromised choroidal perfusion in the development of RAP. (Am J Ophthalmol 2013;155:743-749. (C) 2013 by Elsevier Inc. All rights reserved.)