Comparison of corneal surface effects of gatifloxacin and moxifloxacin using intensive and prolonged dosing protocols.
OBJECTIVE
To compare the effects of the commercial formulations of moxifloxacin and gatifloxacin on rabbit corneal epithelium using two dosing protocols: high-frequency dosing for bacterial keratitis and cataract surgery prophylaxis.


METHODS
Forty eyes of 20 New Zealand white rabbits were randomized to receive topical gatifloxacin, topical moxifloxacin, or no drops as controls. Eighteen eyes received 1 drop of antibiotic every 5 minutes for 15 minutes followed by 1 drop every 15 minutes for 4 hours. Twelve eyes received topical gatifloxacin or topical moxifloxacin 4 times a day for 10 days. Rabbits were euthanized, eyes enucleated, and the corneas separated, washed, and fixed; scanning electron microscopy was performed. Photomicrographs of three separate areas from the corneal apex were taken at x1200 and x3000 for each cornea. Two masked, experienced examiners then graded the corneal epithelial damage.


RESULTS
In the high-frequency dosing group, mean corneal damage score for eyes treated with gatifloxacin was 1.593, that for moxifloxacin was 1.407, and control was 1.000. No statistically significant difference was found between gatifloxacin and moxifloxacin (P = 0.41), gatifloxacin and control (P = 0.14), or moxifloxacin and control (P = 0.23). In the cataract surgery prophylaxis group, mean corneal damage scores for eyes treated with gatifloxacin was 1.167, that for moxifloxacin was 1.368, and control was 1.000. No statistically significant difference was found between gatifloxacin and moxifloxacin (P = 0.23), gatifloxacin and control (P = 0.08), or moxifloxacin and control (P = 0.23).


CONCLUSIONS
Despite differences in formulations, with short-term dosing neither gatifloxacin nor moxifloxacin appears to be toxic to the corneal epithelium in this rabbit model.
Herrygers
Lisa A
LA
Department of Ophthalmology, University of Arizona, Tucson, Arizona, USA.
Noecker
Robert J
RJ
Lane
Lisa C
LC
Levine
Jason M
JM
D000818:Animals; D000891:Anti-Infective Agents, Local / Q000008:administration & dosage* / Q000633:toxicity; D019072:Antibiotic Prophylaxis; D001372:Aza Compounds / Q000008:administration & dosage* / Q000633:toxicity; D002387:Cataract Extraction; D019573:Epithelium, Corneal / Q000187:drug effects* / Q000648:ultrastructure; D015818:Eye Infections, Bacterial / Q000188:drug therapy / Q000517:prevention & control; D024841:Fluoroquinolones / Q000008:administration & dosage* / Q000633:toxicity; D000077734:Gatifloxacin; D008855:Microscopy, Electron, Scanning; D000077266:Moxifloxacin; D019055:No-Observed-Adverse-Effect Level; D011804:Quinolines / Q000008:administration & dosage* / Q000633:toxicity; D011817:Rabbits
D000891:Anti-Infective Agents, Local; D001372:Aza Compounds; D024841:Fluoroquinolones; D011804:Quinolines; D000077734:Gatifloxacin; D000077266:Moxifloxacin