AGE-RELATED AND LIGHT-ASSOCIATED RETINAL CHANGES IN FISCHER RATS

  • 1 January 1978
    • journal article
    • research article
    • Vol. 17  (7) , 634-638
Abstract
Morphological changes in retinas of aging Fischer 344 rats were characterized. The numbers of photoreceptor cells gradually decreased as rats aged. The outer nuclear layer was 12 cells thick at 3 mo., but was reduced to less than 8 cells by 18 mo. The decrease of photoreceptor cells was more pronounced in rats housed under a light intensity of 32 ft-c than in rats housed under a light intensity of 1 ft-c. Inner and outer segments of surviving photoreceptor cells were morphologically normal. A new form of retinal degeneration was discovered in aged Fischer rats characterized by selective degeneration of peripheral retina. Degeneration was characterized by severe loss of photoreceptor cells in the far peripheral retina. Microcystoids were found in about 25% of the affected retinas, and the loss of photoreceptor cells was followed by proliferation and vascularization of the retinal pigment epithelium and disorganization of retinal structures. The incidence and severity of peripheral retinal degeneration increased with age and prolonged exposure to comparatively high-intensity light. All Fischer rats (5/5) housed under light intensity of 32 ft-c developed severe peripheral retinal degeneration by 24 mo. Peripheral retinal degeneration was an age-related change, but appeared to be exaggerated by ambient light.

This publication has 1 reference indexed in Scilit: