Morphometric analysis of Bruch's membrane, the choriocapillaris, and the choroid in aging.

Thickness of Bruch's membrane was only related to age (rs = 0.63) and not to age-related atrophy of the choriocapillaris. Age was also the strongest factor related to choriocapillary density (rs = -0.58). In advanced stages of age-related macular degeneration, the decrease in choriocapillary density and diameter was significantly larger than in normal maculae, but the thickness of the choroid and Bruch's membrane was the same. The latter was significantly thinner (81% of normal) in disciform scarring.