Distinguishing Factors for Microbial Keratitis Groups: A Cross-Sectional Survey of US Cornea Specialists

Purpose: To survey United States (US) cornea specialists on clinical factors that distinguish between microbial keratitis (MK) organism groups. Methods: This cross-sectional survey of US cornea specialists assessed whether 61 clinical factors, including history factors, ocular symptoms, and exam findings, distinguished a specific organism group in the typical patient with MK. MK organism groups included gram-positive bacterial keratitis (GPBK), gram-negative bacterial keratitis (GNBK), mold fungal keratitis (MFK), yeast fungal keratitis (YFK), parasitic keratitis (PK), and viral keratitis (VK). The survey was distributed via the Cornea Society's email listserv from March 11, 2024 to May 7, 2024. Descriptive statistical analysis was performed to identify the percentage of specialists identifying a clinical factor as distinguishing a specific MK organism group. Results: A total of 67 specialists completed the survey. There were 20 factors (32.8% of 61) that >75% of specialists identified as distinguishing a specific MK group, including 9 factors for BK (eg copious ocular discharge, loose ocular sutures), 3 factors for FK (eg feathery infiltrate, ocular trauma with organic matter), 5 factors for PK (eg pain out of proportion, perineuritis), and 3 factors for VK (eg reduced/absent corneal sensation, prodromal symptoms). The remaining 41 factors had ≤75% of specialists identify them as distinguishing. Conclusions: Specialists agreed that 32.5% of clinical factors distinguished different MK organism groups, aligned with prior work demonstrating difficulty with interorganism differentiation. These 20 factors may aid clinicians in their initial MK diagnosis; however, more work is needed to validate their salience in diagnosis.