title: The comparison of fluoroquinolones to nonfluoroquinolone antibacterial agents for the prevention of endophthalmitis in a rabbit model.
abstract: OBJECTIVE
  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.affiliation: The Charles T. Campbell Ophthalmic Microbiology Laboratory, University of Pittsburgh Medical Center, Pittsburgh, Pennsylvania, USA. kowalskirp@upmc.edu
authors.forename: Regis P
authors.initials: RP
authors.lastname: Kowalski
authors.forename: Eric G
authors.initials: EG
authors.lastname: Romanowski
authors.forename: Robert M Q
authors.initials: RM
authors.lastname: Shanks
authors.forename: Francis S
authors.initials: FS
authors.lastname: Mah
mesh_terms: D060433:Administration, Ophthalmic; D000818:Animals; D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D004195:Disease Models, Animal; D009877:Endophthalmitis / Q000382:microbiology / Q000517:prevention & control*; D015818:Eye Infections, Bacterial / Q000382:microbiology / Q000517:prevention & control; D024841:Fluoroquinolones / Q000494:pharmacology*; D011817:Rabbits; D013203:Staphylococcal Infections / Q000382:microbiology / Q000517:prevention & control*; D013211:Staphylococcus aureus / Q000187:drug effects / Q000302:isolation & purification; D018709:Statistics, Nonparametric; D013997:Time Factors
chemical_list: D000900:Anti-Bacterial Agents; D024841:Fluoroquinolones