Abstract
Purpose: :
Manganese superoxide dismutase (MnSOD) is a potent antioxidative agent that was shown to affect formation of lenticular opacities in in-vitro studies. The purpose of this study was to evaluate the in-vivo effect of MnSOD on post-radiation cataracts.
Methods: :
Four groups of C57BL/6J mice were followed with lens photography: control group (n=5), MnSOD only (n=5), radiation only (n=15) and radiation plus MnSOD (n=15). Radiated mice were exposed to 10Gy of total body radiation. MnSOD 100µg was injected intra-peritoneally prior to the radiation. All photographs were graded by an experienced observer.
Results: :
Twenty-seven weeks after radiation, 10% of the control eyes, 11% of the MnSOD only, 67% of the radiation only and 38% of radiation plus MnSOD had lenticular opacities (p=0.006, Chi square test). From that point, the percentage of eyes with lens opacities climbed to 100% in the radiation only group within 6 weeks and within 16 weeks in the radiation plus MnSOD group. Throughout the follow-up, the lens opacities in the radiation plus MnSOD eyes were substantially less severe than those observed in the radiation only group.
Conclusions: :
MnSOD had a statistically significant effect on the rate of development and severity of radiation induced cataract in mice. This might indicate that MnSOD blocks one of the causative pathways of radiation induced lenticular opacity formation or that it modulates the effect of radiation to reduce the impact of a given exposure.
Keywords: antioxidants • cataract