Role of Topically-Applied Zinc Sulfate in Prevention of Sodium Selenite-Induced Cataract in Rabbits

Background: cataract is the opacity of the lens which progressively impairs the light transmission to the retina and finally prevents the vision, this opacity results from the oxidative process in the eye. Zinc sulfate has an antioxidant property which can prevent the oxidative processes. The present study aimed to evaluate the possible protective role of zinc sulfate eye drops against sodium selenite-induced cataract in rabbits. Materials and Methods: In order to induce lens opacity, sodium selenite (0.01w/v) were injected intravitreal into eyes of the included rabbits which were already divided into control (distilled water) group (n= 6) and treatment (zinc sulfate) group (n= 6). Each of distilled water and zinc sulfate (tested drug) eye drops were instilled both prior and then along 21 days post injection of sodium selenite. By using ophthalmoscope grading criteria, the score of lens opacity (cataract maturity) was determined. Results: In control group, the lenses, opacities could be induced within 48 -72 hours of sodium selenite injection and their mean score reached to 4.0 (± 0.00). On the other hand and in comparison to that of control group, zinc sulfate eye drops could highly significantly retard the progression of the induced opacities and mean score of opacity was only 1.33 (± 0. 04) (p < 0.01). Conclusions: Zinc sulfate eye drops exerted a detectable preventive effect against sodium selenite - induced cataract in rabbits.