Systemic prophylaxis of experimental staphylococcal endophthalmitis: comparative efficacy of sparfloxacin, pefloxacin, imipenem, vancomycin, and amikacin.

The preventive efficacy of several antibiotics in experimental staphylococcal endophthalmitis was evaluated. Two hours before bilateral intravitreal infection with 500 cfu of Staphylococcus aureus, 18 pigmented phakic rabbits were assigned to receive a single intramuscular injection of sparfloxacin (50 mg/kg), pefloxacin (50 mg/kg), imipenem (50 mg/kg), vancomycin (30 mg/kg), amikacin (15 mg/kg), or saline and were killed 24 h after infection (6 eyes/group). Sparfloxacin, pefloxacin, and imipenem were significantly (P < .001) more effective than saline. All but 1 of the sparfloxacin-treated eyes were culture negative. To determine whether the effect persisted, an additional 24 rabbits were treated with sparfloxacin, pefloxacin, imipenem, or saline and were killed 48 h after infection (12 eyes/group). Sparfloxacin, pefloxacin, and imipenem were effective (P < .001). All sparfloxacin-treated eyes remained culture negative. These results show that systemic antibiotic administration prevents the development of experimental endophthalmitis and that further studies of sparfloxacin as a prophylactic agent are warranted.