The Utility of Corneal Cultures in Bacterial Keratitis

Abstract

Objectives: To determine the utility and use of corneal cultures in bacterial keratitis. Methods: Retrospective single-center chart review of patients with bacterial keratitis who showed a positive corneal culture result from January 2017 to December 2021. Results: Seventy-four cases of bacterial keratitis in 73 patients with positive cultures were identified. The most common organisms were Pseudomonas, Staphylococcus, and Streptococcus species. In total, 87.8% of cases were started on fortified antibiotics initially. All organisms isolated were susceptible to empiric antibiotics used (n=54). In 47.3% of cases, an antibiotic was discontinued once culture results became available, most often fortified vancomycin. Within the 27 Pseudomonas cases, consisting of predominantly contact lens wearers, at least one fortified antibiotic was discontinued in 66.7% of cases after a positive culture result. Conclusions: Multidrug resistance was infrequent in the study population. Empiric antibiotic therapy is still effective in bacterial corneal ulcers. Corneal cultures may have utility in antibiotic de-escalation.