Protection by iodide of lens from selenite-induced cataract.

Background: Iodide has been used empirically against different age-related eye diseases, including cataract. The purpose of the present study was to investigate the effect of iodide on selenite-induced cataract in rat lens.

Methods: Young white rats received subcutaneously sodium selenite (20 and 30 nmol/g b.w.) on day 13 post partum (p.p.). Cataract development was measured by expert estimation and image data analysis. Potassium iodide (1.5 nmol/g b.w.) was given (1-5 times) i.p. at different times with respect to the selenite administration. Lens opacification was analyzed in selenite, selenite-iodide, iodide and control groups on day 7 after selenite administration.

Results: Iodide showed a significant protective effect against selenite cataract when injected 2 days (2 times) before selenite injection, i.e., on days 11 and 12 p.p. No significant effects on lens opacity were found: (1) after only one iodide injection (on day 12 p.p.), (2) after an initial iodide administration 1 h before selenite and (3) after injections of iodide once a day for 5 consecutive days. The protective effect of iodide was the same (about 50%) for both selenite doses used.

Conclusions: There is a time-dependent protective influence of iodide against selenite cataract development. It is supposed that the anticataract effect of iodide could be based on direct or indirect antioxidant mechanisms.