Morphological study of age-related changes in Fischer rat lens.

The authors conducted a morphological investigation of age-related changes in the lens of male Fischer rats at 6, 12, 18 and 24 months of age. At 6 months, there were no abnormalities of particular note other than slight swelling of the subcapsular fibers. Moreover, other than a slight decrease in the density of epithelial cells and slightly more extensive fiber swelling, there were no remarkable changes seen in the lens at 12 months. At 18 months of age, posterior invasion by the processes of the cortical lens fibers toward the lens capsule and slight swelling of the anterior cortical fibers were seen in addition to the above-mentioned changes. By 24 months of age, these changes had become more noticeable, with further reduction in the density of epithelial cells, swelling and degeneration of both anterior and posterior fibers and extension of the thin processes of the equatorial fibers toward the capsule. However, the bow configuration at the equator appeared almost normal. These findings indicate that the age-related changes in the Fischer rat lens occurred in the epithelial cells and superficial layer of the cortical fibers, subsequently leading to the loss of clarity in the lens.