Effects of timoptic on corneal reepithelialization
W. J. O'Brien, J. D. DeCarlo, M. Stern and R. A. Hyndiuk
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.
