Ocular Microbiology and Immunology Group
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2026 OMIG Abstract

POSTER PRESENTATION


Cornea Specialists' Agreement on Classification of Infectious Stromal Infiltrates Versus Healed Post-Infectious Scars in Microbial Keratitis

Ramadhan Ahmed¹, Kamini Reddy¹, Allen Eghrari¹, Isa Mohammed¹, Imane Tarib¹, Manisha Acharya², Nupur Gupta², Gautam Parmar³, Rashmita Ravishankar⁴, Josephine Christy⁴, and Nakul Shekhawat¹,
on behalf of the International Multicenter Partnership for Advancing Corneal Transplantation

¹Wilmer Eye Institute, Johns Hopkins University School of Medicine, Baltimore, Maryland; ²Shroff Charity Eye Hospital, New Delhi, India; ³SNC Chitrakoot, Madhya Pradesh, India; ⁴Aravind Eye Hospital, Pondicherry, India

Purpose: Cornea specialists frequently classify microbial keratitis lesions as "active" infectious infiltrates versus "healed" post-infectious scars, but inter-grader agreement on this subjective binary assessment has not been quantified. The purpose of this study was to quantify agreement on this classification using slit lamp photographs and assess whether agreement varies by disease stage, microbiologic subtype, and grader country.

Methods: Eight experienced cornea specialists independently classified 103 serial diffuse illumination slit lamp photographs from 36 unique eyes with microbiologically confirmed microbial keratitis. An independent cornea specialist classified all images by microbial keratitis disease stage (active infection, mid-healed, post-infection). Inter-grader agreement across the eight image graders was summarized using Fleiss' kappa (κ), pairwise Cohen's kappa, and the proportion of images receiving a unanimous classification, with 95% confidence intervals derived from a patient-clustered bootstrap (1,000 replicates). Analyses were performed for the overall image library as well as 3 microbial keratitis disease stages, bacterial versus fungal keratitis, and 3 U.S.- versus 5 India-based cornea specialist graders.

Results: All 8 graders agreed unanimously on assessment of active infectious infiltrates versus healed post-infectious scars in 40 of 103 images (38.8%, 95% CI 29.2%-48.5%). The proportion of eye images labelled active infectious infiltrates varied from 23.3% to 60.2% across individual graders. Overall Fleiss' κ was 0.52 (95% CI 0.43-0.60). Pairwise Cohen's κ across 28 unique grader pairs ranged from 0.33 to 0.77. Across all 3 disease stages, fair to moderate agreement was observed, with the lowest agreement for mid-healed stage (active infection: κ = 0.39; mid-healed: κ = 0.22; post-infection: κ = 0.36). Agreement was higher for fungal than bacterial lesions (κ = 0.60 vs. 0.48). Overall percent agreement was 65.1% (95% CI 56.9%-72.8%) among the three U.S.-based graders and 51.5% (95% CI 40.0%-62.4%) among the five India-based graders. Fleiss' κ was nearly identical within the U.S. (κ = 0.53) and Indian (κ = 0.53) subgroups.

Conclusions: Cornea specialists demonstrated fair to moderate agreement on the "active" versus "healed" status of microbial keratitis infectious lesions, with substantial uncertainty in the mid-healed phase of disease. This emphasizes the need for more objective criteria for monitoring infection resolution.