The effect of high and very low fluorescent light exposure levels on age-related cataract in a pigmented mouse strain

This study examined the effect of fluorescent light on the timing and sever ity of age-related cataracts in a fully pigmented mouse strain, the (C57BL/ 6 x C3H)F1, that normally develops slowly progressing age-related cataracts only beyond middle age. Two groups of 56 animals each were exposed, respec tively, either to a daily range of 66-222 foot candles (FC) or to 1 FC of s tandard fluorescent lighting for a period beginning at 5 weeks of age and e nding at 33.5 months (by which time approximately 65% of the colony had die d). Contrary to previous reports involving albino rats or mice and a strain of pigmented but cataract-prone transgenic mice, the two groups of animals in this experiment did not differ for cataract development in time of firs t occurrence, rate of advancement, or degree of severity. It was concluded that genetic predisposition, based on levels of oxidative free radical prod uction vs antioxidant enzyme and repair enzyme protection in the lens, was probably the major factor governing the rate and degree of age-related cata ract development in these animals. The effect of relatively intense life-lo ng fluorescent light exposure was so minimal as not to be manifested in thi s strain of mice under the conditions of this experiment. Remarkably mainta ining the one group of mice in semi-darkness from 5 weeks of age to beyond their mean lifespans did nothing to delay or reduce the incidence or severi ty of their age-related cataracts. (C) 2001 Academic Press.