Prediction of Visual Acuity in Patients With Microbial Keratitis

Abstract

The purpose of this study was to predict visual acuity (VA) 90 days after presentation for patients with microbial keratitis (MK) from data at the initial clinical ophthalmic encounter. Methods:Patients with MK were identified in the electronic health record between August 2012 and February 2021. Random forest (RF) models were used to predict 90-day VA , 20/40 [visual impairment (VI)]. Predictors evaluated included age, sex, initial VA, and information documented in notes at presentation. Model diagnostics are reported with 95% confidence intervals (CIs) for area under the curve (AUC), misclassification rate, sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV).Results: One thousand seven hundred ninety-one patients were identified. The presenting logMAR VA was on average 0.86 (Snellen equivalent and standard deviation = 20/144 6 12.6 lines) in the affected or worse eye, and 43.6% with VI. VI at 90-day follow-up was present in the affected eye or worse eye for 26.9% of patients. The RF model for predicting 90-day VI had an AUC of 95% (CI: 93%-97%) and a misclassification rate of 9% (7%-12%). The percent sensitivity, specificity, PPV, and NPV were 86% (80%-91%), 92% (89%-95%), 81% (74%-86%), and 95% (92%-97%), respectively. Older age, worse presenting VA, and more mentions of "penetrating keratoplasty" and "bandage contact lens" were associated with increased probability of 90-day VI, whereas more mentions of "quiet" were associated with decreased probability of 90-day VI.Conclusions: RF modeling yielded good sensitivity and specificity to predict VI at 90 days which could guide clinicians about the risk of poor vision outcomes for patients with MK.

Social Risk Factor Associations With Presenting Visual Acuity in Patients With Microbial Keratitis

“…Laterality of MK was determined by ICD-10 codes when available. If ICD-10 codes were not sufficiently specific or if ICD-9 codes were used, then natural language processing of the note was applied to classify MK laterality, as has been previously described by our group . For each patient, the first date of MK diagnosis identified in the EHR was designated as the date of MK presentation.…”

Infectious Keratitis in Patients Over 65: A Review on Treatment and Preserving Eyesight

“… 59 The elderly age group has also been seen to have an increased probability of 90-day visual impairment (VA < 20/40). 62 These trends in microbial keratitis are also seen in the subgroup of bacterial keratitis where elderly patients have poor visual outcomes compared to individuals < 65 years. Specifically, Ly et al reported that their poor outcome subgroup had an average age of 67 years compared to 50 years.…”