J Korean Ophthalmol Soc.  2021 Nov;62(11):1465-1477. 10.3341/jkos.2021.62.11.1465.

Comparative Clinical Analysis of Polymicrobial and Monomicrobial Bacterial Keratitis

• Baek SC
• Cho CH
• Lee SB

• KMID: 2522323
• DOI: http://doi.org/10.3341/jkos.2021.62.11.1465

Abstract

Purpose
We comparatively analyzed the microbiological profiles, predisposing factors, clinical aspects, and treatment outcomes of patients with polymicrobial and monomicrobial bacterial keratitis.
Methods
A total of 194 cases of culture-proven bacterial keratitis treated between January 2007 and December 2016 were reviewed. Microbiological profiles, the epidemiology, predisposing factors, clinical characteristics, and treatment outcomes were compared between the polymicrobial group (polymicrobial bacterial keratitis [PBK]; 29 eyes, 62 isolates) and monomicrobial (monomicrobial bacterial keratitis [MBK]; 165 eyes, 165 isolates) group.
Results
The most common isolates were Enterobacter (24%) in the PBK group and Staphylococcus (22%) in the MBK group. There were no significant differences between the two groups in previous ocular surface disease, previous ocular surgery, prior topical steroid use, epithelial defect size, and hypopyon. Age ≥60 years (PBK vs. MBK, 31% vs. 51%, p = 0.048), symptom duration (4.7 days vs. 8.0 days, p = 0.009), and contact lens use (34% vs. 18%, p = 0.036) were significantly different between the two groups. Regarding treatment outcomes, epithelial healing time ≥10 days, the final best-corrected visual acuity (BCVA), a need for surgical intervention, and the rate of poor clinical outcome were not significantly different between the two groups. Significant risk factors for a poor clinical outcome in all patients were an initial BCVA <0.1 (Z = 6.33, two-proportion Z-test), an epithelial defect size ≥5 mm² (Z = 4.56), and previous ocular surface disease (Z = 4.36).
Conclusions
Polymicrobial bacterial keratitis, compared to monomicrobial bacterial keratitis, was more significantly associated with younger age, contact lens use, and shorter symptom duration.

Keyword

Bacterial keratitis, Corneal ulcer, Polymicrobial infection