Histologic features of the early stages of age-related macular degeneration : a statistical analysis

The age distribution, frequency, and correlation among histologic macular changes, including formation of a basal laminar deposit, drusen, and thickening and calcification of Bruch's membrane, were studied by light microscopy. The authors studied 182 unpaired postmortem human maculae from patients between 8 and 100 years of age. In addition, 45 maculae of contralateral eyes and the peripheral retina of 50 eyes were studied. In 92%, Bruch's membrane was thickened starting at age 19, and calcifications in this membrane were found in 59% starting at age 33. In 37% of the maculae, hard drusen were found starting at age 34. Soft drusen were found in 10% beginning at age 54. Basal laminar deposit was found in 39% of the maculae starting at age 40. All changes correlated strongly with age (P less than 0.0001). No sex differences were found. Fellow eyes showed similar aging changes (P less than 0.001). The presence of basal laminar deposit in the macula correlated with basal laminar deposit-like material in the peripheral retina (correlation coefficient, 0.39; P less than 0.003), whereas drusen in the macula correlated with drusen in the peripheral retina (correlation coefficient, 0.42; P = 0.001). Geographic atrophy was found in 6.6% of the eyes from subjects older than 70 years and subretinal neovascularization in 3.8%, especially in the maculae with basal laminar deposit.