Epidemiology and Outcome of Microbial Keratitis: Private University Versus Urban Public Hospital Care

To review the epidemiology, risk factors, microbiologic spectrum, and treatment of microbial keratitis during a 5-year period at an urban public hospital in comparison with an adjacent private university practice.

Retrospective chart review in the 5-year interval, 2009 through 2014. Primary outcome measures included patient age at presentation, best-corrected visual acuity (BCVA), risk factors, culture and sensitivities, treatment, and complication occurrence.

A total of 528 eyes with microbial keratitis were identified, 318 in the public cohort and 210 in the private cohort. Contact lens wear was the most common risk factor in the public cohort, whereas ocular surface disease was the most common risk factor in the private cohort. Gram-positive organisms represented 47.3%, gram-negative organisms 32.1%, fungal organisms 13.6%, and Acanthamoeba 6.4% of corneal isolates. Gentamicin resistance was 4.4% and tobramycin resistance was 2.9%. The inpatient treatment rate of the public cohort was 40% compared with 4% in the private cohort. In the public cohort, average BCVA at resolution was 20/82 (log of minimal angle of resolution [logMAR] 0.61). For the private cohort, average BCVA at resolution was 20/73 [logMAR, 0.56]. The perforation rate was 8% in the public cohort compared with 4% in the private cohort. Six percent of cases underwent urgent penetrating keratoplasty in the public cohort versus 2% in the private cohort.

Microbial keratitis remains a clinical challenge in the urban public hospital setting. The risk profile of patients presenting in the public hospital setting may be different from patients presenting in a private care setting. Public hospital patients may present later in the course of their infection and thus have a higher rate of complications regardless of effective antimicrobial therapy.