The effect of white light exposure on the rabbit eye lens as measured by fluorophotometry and spectrophotometry

Fluorophotometry and spectrophotometry of the rabbit lens were performed after white light exposure to detect possible changes in the lens before damage could be seen by biomicroscopic slit lamp examination. In nine rabbits the lens of one eye was exposed to white light and that of the fellow eye was used as a control. The incident light power was 240 mW for 90 min on a lenticular area of 3 mm2. Slit lamp examination of lens and cornea prior to, 1 hr after and 2 days after light exposure did not reveal any sign of damage. The mean in vivo autofluorescence ratio between exposed lens and non-exposed fellow lens was found to increase significantly from 1.0 +/- 0.08 S.D. (n = 9) before exposure to 3.3 +/- 0.8 S.D. (n = 9; P less than 0.004) 1 hr after exposure and hereafter to decay exponentially with a half time of 0.8 days to the ratio before exposure (correlation coefficient: -0.97, P = 0.0013). Three additional rabbits were exposed as described above with subsequent in vitro spectrophotometry of the lenses between 400 and 800 nm revealing an absorbance peak at 468 nm with a half width of 10 nm. The ratio between the absorbance peak of exposed lens and non-exposed fellow lens was found to increase from 1.1 before exposure to 2.8 1 hr after exposure and then to decrease to 1.4 at 1 day after exposure. The corresponding autofluorescence ratios measured in vivo before spectrophotometry were 0.93, 2.6 and 1.5, respectively.(ABSTRACT TRUNCATED AT 250 WORDS)