Aging changes in lipofuscin, lysosomes and melanin in the macular area of human retina and choroid.

Biochemical examination was carried out on the lipofuscin content, lysosomal enzyme activities and melanin level in the retina and choroid of normal human eyes. Lipofuscin content, expressed as fluorescence intensity, in the macular retinal pigment epithelium (RPE) and choroid was two-to-three fold higher than that in other areas, and increased with aging. High activities of lysosomal enzymes in the macular area were found, but did not change with aging. Melanin level was two-to-three fold higher in the macular RPE and choroid than in other areas, and showed no alteration with aging.