Effects of Timoptic on Corneal Reepithelialization

• The effects of topical 0.5% Timoptic on the reepithelialization of rabbit corneas were compared to the effects observed in rabbits receiving either vehicle, phosphate-buffered saline (PBS), PBS containing 0.5% timolol maleate, or no treatment. The rate of epithelial wound closure was slowed, and epithelial DNA content was less in both Timoptic- and vehicle-treated corneas. Light microscopy showed that the epithelium of animals treated with either Timoptic or vehicle processed fewer cellular layers in the wounded areas as well as considerable disruption of the epithelial layer. The rate of DNA synthesis and the cyclic adenosine monophosphate content of the epithelial cells from all treatment groups were statistically the same. The impaired wound closure observed during Timoptic and vehicle treatment was probably due to the sloughing of cells caused by the 0.01% benzalkonium chloride in the vehicle and not to impaired healing caused by the metabolic effects of timolol meleate.