ABSTRACT
To evaluate the influence of UV-B radiation on the cornea and epithelial cells of the albino rat. 100 Sprague-Dawely rats were divided in 4 groups with different ages [3, 6, 10, 18 weeks] and control one. Exposed 4 groups were irradiated to UVB with wave length 300nm and intensity of 8 kj/m2. Each group was divided into 2 sub-groups [A and B] according to the time of exposure [15 and 30 minutes]. The control group [C] was divided into 5 rats for each group. One week after exposure cornea was removed to evaluate the histopathological changes. Groups were compared by evaluating the difference between exposed and non-exposed cornea. Exposure to 15 minutes UV-B showed degenerative changes in all ages and increased with time of exposure. Epithelial hyperplasia was 25% in 6 weeks group exposed to 15 minutes of UV-B and 33.3% with 30 minutes of exposure. In 18 weeks group hyperplasia was 25% after 30 minutes of exposure. Epithelial thinning was detected only in 3 and 18 weeks groups after exposure to 30 minutes of UV-B by 33.3%. Epithelial erosion was 16.6% in 10 weeks group after 30 minutes of exposure. Stromal blood vessels were detected in exposed groups to 30 minutes of radiation in 6, 10 weeks by 16.6% and 41.6%. Stromal edema was detected in all ages exposed to 15 and 30 minutes of UV-B. Exposure to UV-B comeal epithelial and stromal changes which increase with time of exposure