Effects of Ultraviolet B Radiation on the Cornea of Adult Male Albino Rats and the Possible Role of Lornoxicam: A Histological, Immunohistochemical and Morphometrical Study

Introduction: Ultraviolet Radiation (UVR) represents a significant environmental and occupational hazard to human beings especially after the ozone hole. Lornoxicam is a strong non-steroidal anti-inflammatory drug (NSAID) with few side effects. Aim of the Work: This work aimed to clarify effects of UVBR on the cornea of adult male albino rats and the possible role of lornoxicam. Materials and Methods: Thirty adult male albino rats were used. They were divided into three main groups: Control; Lornoxicam treated and UV irradiated which was further subdivided into 3 subgroups. On sacrifice, cornea was processed for histological, immunohistochemical and morphometrical studies. Results: Cornea of UV irradiated rats revealed epithelial thinning with cellular degeneration, exfoliation and metaplasia. Bowman s membrane was focally interrupted or absent. Stroma showed irregularly arranged widely separated collagen fibers, degenerated few keratocytes with neovascularization, interstitial hemorrhage and cellular infiltration. Ultrastructurally, epithelial cells showed nuclear membrane irregularities, chromatin condensation, mitochondrial degeneration and loss of rER. Immunohistochemically, epithelial cells and keratocytes showed marked expression of caspase-3 protein in their cytoplasm. Morphometrically, there was a highly significant decrease in epithelial thickness, area % of stroma and number of keratocytes. Rats left to recover without treatment showed mild improvement, while treatment of irradiated rats with lornoxicam for one week after exposure showed nearly normal histological, ultrastructural, and immunohistochemical pictures. Conclusion: Lornoxicam (a cheap, available tolerable NSAID) could ameliorate UVB induced corneal changes. So it could be considered as a curative measure of the cornea against UVB.