ULTRASTRUCTURAL AND MORPHOMETRIC ASPECTS OF AGING IN THE RETINAL CAPILLARIES OF RATS

Age-related morphological, ultrastructural and morphometric changes in the capillaries of the superficial and deep plexuses of the rat retin a were studied in animals aged from 3 to 15 months. Our results sugges t that age-related morphological alterations start occurring in the re tina of rats at about 12 months of age. Increased glycogen deposits, p inocytotic vesicles, residual bodies and cell debris were observed ed in both the endothelial and pericytic cells of 12-and 15-month-old ani mals. In addition, heterogeneous osmiophilic accumulations, electron-t ransparent spaces were observed in the basement membrane as well as pr ojections of the basement membrane towards the neighboring cells. Morp hometric examination of the two vascular plexuses studied did not show differences in the area of the endothelial or pericytic cells, baseme nt membrane or vascular lumen between rats of different ages.