Effects of commonly used topical medications on the rate of corneal reepithelialization following excimer laser keratectomy

Objective. To determine the effect of eight commonly used topical medications on the rate of corneal epithelial wound healing after excimer laser keratectomy. Methods. Six millimeter corneal epithelial defects were created in both eyes of 32 New Zealand white rabbits using a VISX 20/20 excimer laser. Rabbits were randomly assigned to one of eight treatment groups (Refresh Plus; diclofenac sodium, 0.1% (Voltaren); ketorolac, 0.5% (Acular); fluorometholone, 0.1% (FML); ofloxacin, 0.3% (Ocuflox); ciprofloxacin, 0.3% (Ciloxan); tobramycin, 0.3% (Tobrex); and gentamicin, 0.3% (Genoptic)). One eye received a topical medication six times a day and the other eye served as a control. Serial standardized color photography of the fluorescein-stained defects and computer-assisted planimetry of the projected photographs was used to quantitate epithelial defect areas, and the average daily rate of corneal epithelial wound healing was then calculated. Results. Compared to the other topical agents studied, fluorometholone 0.1% (4.67±1.14 mm²/day), and tobramycin 0.3% (5.70±1.15mm²/day), had the slowest mean wound healing rates (P < .001). The mean wound healing rates between fluorometholone and tobramycin were not statistically different. Similarly, the rates for all the other agents (8.34±1.08 to 9.93±1.14mm²/day) showed no significant difference. Comparison of wound healing rates between treated eyes and control eyes showed no significant difference for any of the topical medications studied. Conclusions. Fluorometholone, 0.1% and tobramycin, 0.3% significantly slow the rate of epithelial healing after excimer laser keratectomy in the rabbit compared to other commonly used topical medications. Our data also indicates that a significant cross-over effect occurs when the contralateral eye is used as a control.