Age-related changes of sulfated proteoglycans in the human lamina cribrosa

Abstract

Sulfated proteoglycans in the lamina cribrosa of the optic nerve head from individuals aged 2 months, 18 months, and 23, 35, 44, 55, 67, 74, and 88 years were studied by electron microscopy after cuprolinic blue dye binding. Within the cores of the laminar plates, cuprolinic blue-positive chondroitin/dermatan sulfate proteoglycan filaments of different sizes were found associated with collagen fibers. In addition, small punctate and filamentous structures that represented heparan sulfate proteoglycan molecules were associated with the basal laminae of astrocytes and blood vessels. In the eyes of older individuals, the chondroitin/dermatan sulfate and heparan sulfate proteoglycan filaments were found to be shorter than those in younger persons. A mild decline with aging in the diameter of the filaments was also noted. Our findings illustrate the age-related changes in the proteoglycans in the human lamina cribrosa, which may help explain why the optic nerve head is more susceptible to damage with aging.