Aging alterations of retina and choroid of Japanese: light microscopic study of macular region of 176 eyes.

A light microscopic study of the retina and choroid was performed on 176 eyes of the Japanese with the ages ranging from 42 to 96 years with an average of 75 years. The age-related changes were examined with particular emphasis on the retinal pigment epithelium, Bruch's membrane and choriocapillaris. The histological features of the age-related changes of these structures were classified into six groups with increasing severity of pathologic alterations, according to the criteria of Sarks. Of the present 176 eyes, 51 eyes (29%) belonged to Group I, 87 eyes (49.4%) to Group II, 35 eyes (19.9%) to Group III and 3 eyes (1.7%) to Group IV. No eyes could be found that belonged to Groups V and VI. The drusen was classified histopathologically into three types, simple, confluent and continuous drusen. Simple drusen were encountered in many eyes, but confluent and continuous drusen were seen in only 20 eyes (11.4%). In no eyes was retroretinal neovascularization encountered. The present results indicated that severe changes of these structures are less frequent in the Japanese than in the Caucasian. This would account for the low incidence and slow progression of senile macular degeneration in the Japanese as compared to the Caucasian.