Abstract
Abstract: :
Purpose: To analyze the microbiologic spectrum and in vitro susceptibility profiles over the last eleven years of organisms isolated from the vitreous of patients with endophthalmitis following cataract surgery. Methods: Hospital records and microbiologic testing of all patients treated for endophthalmitis at a tertiary-care institution from 7-89 through 6-00 were reviewed. Demographic information, clinical characteristics, results of vitreous culture and in vitro antibiotic susceptibility testing were recorded. Data from the periods 1989-94 and 1995-2000 were compared. Results: 493 consecutive patients with post-cataract endophthalmitis were studied. An organism was cultured from the vitreous in 318 cases (65%). There was a significant increase in Gram-positive isolates (92% to 97%, p<0.05) between the two periods, while Staph. epidermidis remained the most common isolate across the study. Resistance among all isolates to ciprofloxacin rose significantly (23% to 38%), while resistance to ciprofloxacin and cefazolin rose among coagulase-negative staphylococci (18% to 38%). Resistance to vancomycin, bacitracin, and polymyxin B-trimethoprim remained unchanged. Only vancomycin retained in vitro efficacy of over 98%. Ceftazidime was effective against 100% of Gram-negative organisms. Conclusion: The spectrum of pathogens causing post-cataract endophthalmitis is changing, and resistance to commonly-used antibiotics is growing. These findings impact the empiric treatment of post-cataract endophthalmitis, as well as the use and choice of antibiotics in patients undergoing cataract surgery.
Keywords: 398 endophthalmitis • 319 antibiotics/antifungals/antiparasitics • 328 bacterial disease