The comparison of fluoroquinolones to nonfluoroquinolone antibacterial agents for the prevention of endophthalmitis in a rabbit model

摘要

Purpose: Topical antibacterial agents, used as an off-label indication, are frequently administered pre- and postoperatively to prevent endophthalmitis. We compared topical treatment with fluoroquinolone (FQ) anti-infectives to non-FQ antibacterial agents to prevent Staphylococcus aureus endophthalmitis. We hypothesize that FQ anti-infectives are more effective than non-FQ antibacterial agents for preventing endophthalmitis. Methods: Moxifloxacin 0.5%, ofloxacin 0.3%, gentamicin 0.3%, chloramphenicol 0.5%, polymyxin B/trimethoprim (10,000 units/mL/0.1%), povidone-iodine 5%, and saline were tested for topical treatment to prevent endophthalmitis. Topical treatment was applied every 15min for 1h (5 drops) to the left eye of 14 rabbits for each antibacterial agent and saline. After appropriate anesthesia, the anterior chambers were injected with 1×105 colony-forming units of a clinical endophthalmitis isolate of a S. aureus that was susceptible to all tested antibacterials. One drop was administered immediately and another 4 drops of topical treatment were applied over 24h after injection. At 24h postinjection, the eyes were graded for clinical signs of endophthalmitis (ocular discharge, conjunctivitis/scleral injection, limbal injection, hypopyon*, iritis*, anterior chamber cells*, anterior chamber flare*, corneal infiltration, and fibrin production*) using a severity scale (0-3). The indication of clinical endophthalmitis was a total score of 3.0 for the presentations marked with an asterisk. The data were analyzed using Fisher's Exact Randomization or Mann-Whitney nonparametric testing. Results: Topical ofloxacin (14/14, 100% without endophthalmitis) and moxifloxacin (13/14, 93%) prevented the clinical presentation of endophthalmitis significantly more frequently (P=0.03, Fisher's Exact Test (FE)) than topical gentamicin (7/14, 50%), povidone iodine (4/14, 29%), chloramphenicol (0/14, 0%), polymyxin B/trimethoprim (0/14, 0%), and saline (0/14, 0%). The median total clinical scores for the ofloxacin (0.5) and moxifloxacin (0.8) groups were significantly (P=0.008, Mann-Whitney Test (MW)) lower than gentamicin (5.7), chloramphenicol (17.5), polymyxin B/trimethoprim (21.2), povidone-iodine (15.5), and saline (18.7). Conclusions: The FQs, ofloxacin and moxifloxacin, were more effective in preventing endophthalmitis than the non-FQ antibacterial agents in a rabbit S. aureus endophthalmitis model. The observed results are consistent with the hypothesis that FQs penetrate into the anterior chamber at more effective levels than many of the common non-FQ antibacterial agents.