EFFECTS OF ALDOSE REDUCTASE INHIBITOR CT-112 ON THE CORNEAL EPITHELIAL BARRIER OF GALACTOSE-FED RATS

Purpose. To investigate whether the barrier function of the corneal ep ithelium is disrupted in galactosemic rats, and to assess the effects of the aldose reductase inhibitor CT-112, in the form of eyedrops, on the corneal epithelial barrier in galactosemic rats. Methods. Forty ra ts were divided into 3 groups based on their diet: a control group, a galactose group and st CT-112 treated galactose group (CT-112 group). After 3 weeks, 31 rats from the 3 groups were subjected to fluorophoto metry, in which fluorescein (F) was instilled into one eye and carboxy fluorescein (CF) was instilled into the other eye in a random fashion. The F and CF uptakes were then measured at the central cornea by a sl it-lamp fluorophotometer. Three rats from each group were exposed to a horseradish peroxidase (HRP) solution for one hour, and the HRP-react ive Substances within the corneal epithelium were also examined via el ectron microscopy. Results. There was significantly higher F uptake in the galactose group than in the control (p = 0.003) and CT-112 groups (p = 0.028). There were no significant differences in CF uptake betwe en the 3 groups. Histologically, HRP-reactive substances were found in much greater quantities within the superficial corneal cells of the g alactose group than in the control or CT-112 groups. Conclusions. Thes e results suggest that cell membrane disruption, as detected by F upta ke and HRP penetration, was found in the superficial corneal cells of galactose-fed rats, and that intercellular junction integrity can be a ssayed by CF uptake and histological evaluation. Moreover, CT-112 eyed rops were effective in improving the corneal epithelial barrier dysfun ction of galactose-fed rats.