Acute endophthalmitis in eyes treated prophylactically with gatifloxacin and moxifloxacin.

PURPOSE: To study the use of prophylactic fourth-generation fluoroquinolone antibiotics, gatifloxacin and moxifloxacin, and bacterial sensitivity in cases of acute postoperative endophthalmitis following cataract surgery.
DESIGN: Retrospective, consecutive, observational case series.
METHODS: Forty-two eyes of 42 patients with acute endophthalmitis occurring within six weeks after cataract surgery were identified. All patients were seen in a referral vitreoretinal practice over a two-year time interval. The number of patients using prophylactic gatifloxacin or moxifloxacin and results of bacterial culture and sensitivity to all fluoroquinolone antibiotics were recorded.
RESULTS: Thirty-one of 42 eyes (74%) were treated with perioperative gatifloxacin or moxifloxacin and 24 eyes (57%) were continuously taking one of these antibiotics at the time of diagnosis. Nineteen eyes (45%) had a positive bacterial culture. The most frequent organism isolated was coagulase-negative Staphylococcus. Sensitivities were performed for 14 gram-positive organisms, and sensitivities to ciprofloxacin (50%), ofloxacin (44%), levofloxacin (46%), gatifloxacin (38%), and moxifloxacin (38%) were noted. Five organisms were resistant to gatifloxacin and moxifloxacin with a minimum inhibitory concentration of 8 microg/ml. All gram-positive organisms were sensitive to vancomycin. Median visual acuity improved from hand motions to 20/40 at last follow-up.
CONCLUSION: Acute endophthalmitis can develop after cataract surgery despite the prophylactic use of fourth-generation fluoroquinolone antibiotics. Gram-positive organisms causing acute endophthalmitis are frequently resistant to all fluoroquinolones, including a significant number of cases resistant to gatifloxacin and moxifloxacin.