Symptoms as an Indicator of Microbial Keratitis Severity and Its Association With Visual Acuity

Microbial keratitis (MK) is a vision-threatening and often painful corneal infection. This study aims to quantify severity of symptoms of MK at presentation and investigate their association with visual acuity (VA).

The Automated Quantitative Ulcer Analysis (AQUA) study recruited MK patients from two sites (University of Michigan and Aravind Eye Care System). At presentation, best-corrected VA was recorded. Patients were surveyed on severity of symptoms on a five-point scale for pain or a four-point scale for redness, light sensitivity/glare, and blurry vision. The association between symptom severity and VA was tested with Spearman correlations (r) and Kruskal-Wallis tests.

Seven hundred three patients with MK were enrolled in the AQUA study from July 2020 to November 2022. Presenting logMAR VA had a median value of 1.3 (Snellen equivalent, 20/400). Most patients reported pain (98.7%), redness (99.1%), light sensitivity/glare (98.4%), and blurry vision (99.2%). Visual acuity showed a significant correlation with cumulative symptom severity (spearman r=0.15, P <0.0001). For those who reported pain and blurry vision, VA worsened with increasing symptom severity ( P <0.0001).

Presenting VA showed a significant positive correlation with cumulative symptom severity and the individual symptoms of pain and blurry vision. Patient-reported symptoms at MK presentation may indicate disease severity.