ABSTRACT
Purpose To assess the changes in tear composition in rabbits following exposure to Sr90 beta - radiation. Methods The damage induced by beta - radiation from Sr90 applicator, at doses of 20 Gy, 40 Gy and 60 Gy in weekly sitting of 10 Gy to treated left eye and the right untreated one of 25 there-month-old New Zealand white rabbits was assessed. An additional ten rabbits were used as a control. Tears collected after 24 hours were measured for protein content and lysozyme concentration. The lysozyme molecular structure was studied through the use of column chromatography; cellogel paper electrophoresis and radial diffusion technique was utilized for the demonstrated doses. The delayed effects of beta-radiation on tear lysozyme after one and three months' post exposure was also studied. All samples were analyzed six times and the mean result obtained. Results The radiation damage process increased by increasing the exposure doses and this phenomenon still propagated after the study delay periods which reported no remarks for repair. A significant decrease in the lysozyme concentration for the treated and untreated eyes was observed after the dose of 60 Gy [-61.46%] for the treated eye and [-70.64%] for the untreated one. Conclusions Although irradiation has proved to be a valuable tool in controlling eye disease, with excellent survival rates, nevertheless, side effects of radiation form serious limitations for the applicabilities of this technique