To identify the clinical manifestations and risk factors for poor visual outcome, as well as antibiotic susceptibility of isolates in bacterial keratitis.

A total of 128 eyes in 128 patients with bacterial keratitis, who were diagnosed by smears and cultures from January 2000 to December 2007 were reviewed retrospectively. Sex, age, previous ocular disease, trauma history, pre-treatment duration, previous ocular surgery, clinical manifestation, causative bacteria, pre- and post-treatment visual acuity, and treatment results were evaluated. An initial univariate and multivariate logistic regression analysis was performed to identify and select the main prognostic factors. The antibiotic susceptibility was evaluated in 2 consecutive 4-year periods.

The mean age of the 128 patients was 59.0±18.2 years; 67 (52.3%) patients were male. The most common risk factor was ocular trauma (40.6%). The most prevalent isolate was coagulase-negative Staphylococcus (43.7%). Large size ( p < 0.001) and previous ocular disease ( p < 0.001) were significant prognostic factors in the multivariate logistic regression model. Resistance of cefazolin and aminoglycoside antibiotics that were commonly used as a combination therapy increased over the 8 years, but there was no significant difference in the 2 time periods tested (all p > 0.05). Among the fluoroquinolone antibiotics, susceptibility of ciprofloxacin was 75.7%.

In patients with bacterial keratitis, a large ulcer size and the presence of previous ocular disease were risk factors for poor visual outcome. Gentamicin, cefazolin, and ciprofloxacin should be avoided as primary monotherapy for bacterial keratitis.