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

Abstract

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 15 min for 1 h (5 drops) to the left eye of 14 rabbits for each antibacterial agent and saline. After appropriate anesthesia, the anterior chambers were injected with 1×10(5) 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 24 h after injection. At 24 h 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.

• Authors: Regis P Kowalski, Eric G Romanowski, Robert M Q Shanks, Francis S Mah
• Journal: Journal of ocular pharmacology and therapeutics : the official journal of the Association for Ocular Pharmacology and Therapeutics (J Ocul Pharmacol Ther) Vol. 28 Issue 6 Pg. 604-8 (Dec 2012) ISSN: 1557-7732 [Electronic] United States
• PMID: 22925112 (Publication Type: Comparative Study, Journal Article, Research Support, N.I.H., Extramural, Research Support, Non-U.S. Gov't)

Chemical References

• Anti-Bacterial Agents
• Fluoroquinolones

Topics

• Administration, Ophthalmic
• Animals
• Anti-Bacterial Agents (pharmacology)
• Disease Models, Animal
• Endophthalmitis (microbiology, prevention & control)
• Eye Infections, Bacterial (microbiology, prevention & control)
• Fluoroquinolones (pharmacology)
• Rabbits
• Staphylococcal Infections (microbiology, prevention & control)
• Staphylococcus aureus (drug effects, isolation & purification)
• Statistics, Nonparametric
• Time Factors