Antibiotics Susceptibility in Bacterial Keratitis and Proper Initial Treatment

ABSTRACT

PURPOSE: The present study aims to determine the common pathogens involved in the etiology of bacterial keratitis and to analyze not only the antibiotic susceptibility of bacterial isolates from patients with bacterial keratitis but also the propriety of initial treatment. METHODS: A retrospective study of 161 eyes in 161 patients with bacterial keratitis, who were diagnosed by cultures from 2000 to 2011, was performed. Causative bacteria and antibiotic susceptibility were evaluated in consecutive 6-year periods. RESULTS: The most common bacteria was the pseudomonas species in the 2 time periods tested and cefazolin with tobramycin was the most commonly used antibiotic (125 cases, 77.6%) for initial treatment of bacterial keratitis. In vitro testing showed gram-negative susceptibility to tobramycin and ciprofloxacin was over 70%, gram-positive susceptibility to cephalothin and vancomycin was 100% and there was no significant difference between the 2 time periods tested. Eight cases had resistance to the initial treatment, but only 1 case showed treatment failure. CONCLUSIONS: Antibiotics used for initial treatment of bacterial keratitis were able to obtain a proper effect but several cases showed bacterial resistance to antibiotics. Thus, continued testing is essential to monitor for antibiotic resistance.