Morphometric analysis of the choroid, Bruch's membrane, and retinal pigment epithelium in eyes with age-related macular degeneration

Abstract

Purpose: To quantify morphologic changes in the choroid, including choriocapillaris and larger choroidal vessels, Bruch's membrane, and retinal pigment epithelium in eyes with age-related macular degeneration (AMD) and late ARM (age-related maculopathy).

Methods: The authors analyzed 40 eye bank eyes with late ARM (21 with the neovascular AMD and 19 with nonneovascular AMD) and compared them with 40 age-matched eyes without signs of late ARM (AMD). The eyes were processed for light microscopy, and seven variables were measured in the macular and peripheral regions with a digital filar micrometer.

Results: There were no statistically significant differences observed between eyes with neovascular versus nonneovalcular AMD. The single most important difference between eyes with and without AMD was the amount of basal laminar deposit (P < 0.001). Eyes with AMD displayed fewer large choroidal vessels in the submacular choroid than eyes without AMD (3.5 +/- 1.5 mm-1 and 5.7 +/- 1.6 mm-1; P < 0.001). The submacular choriocapillaris density was higher in eyes with AMD (0.62 +/- 0.06) than in eyes without AMD (0.51 +/- 0.08; P < 0.001). The diameter of the large choroidal vessels in the peripheral choroid was increased in eyes with AMD (30 +/- 8 microns) compared to eyes without AMD (21.4 +/- 6.2 microns; P < 0.001). The peripheral choriocapillaris density displayed the same pattern as in the macular region in eyes with and without AMD.

Conclusions: The amount of basal laminar deposit strongly correlates with the histologic presence of AMD. Eyes with AMD show differences of the density and diameter of choroidal blood vessels compared to eyes without AMD.