Morphological and Optical Determinants of Visual Disability in Fuchs Endothelial Corneal Dystrophy.

Abstract

To identify determinants of visual disability in patients with advanced Fuchs endothelial corneal dystrophy. This prospectively sampled cross-sectional study at a tertiary referral center included participants with clinically advanced Fuchs dystrophy requiring endothelial keratoplasty and no other vision-limiting pathologies. We quantified visual disability using the Fuchs dystrophy-specific Visual Function and Corneal Health Status (V-FUCHS) visual disability instrument. We calculated Fuchs dystrophy-specific glare and diurnal variation (Glare Factor) scores and visual acuity-related disability (Visual Acuity Factor) scores. To assess corneal morphology and optics, all participants underwent standardized Scheimpflug imaging and tests for disability glare and best-corrected visual acuity on Early Treatment Diabetic Retinopathy Study charts after subjective refraction. Associations of morphological and optical parameters with V-FUCHS scores were assessed adjusting for age, sex, and lenticular status. Participants with more posterior corneal backscatter had more visual disability (higher scores), with participants in the highest quartile of backscatter (median, 1409 scatter units) having 0.57 higher Glare Factor scores (95% confidence interval, 0.14-1.00) and 0.61 higher Visual Acuity Factor scores (95% confidence interval, 0.15-1.06) compared with participants in the lowest quartile of backscatter (median, 812 scatter units). Other morphological and optical factors such as anterior corneal backscatter, higher-order aberrations, or edematous surface changes were not empirical contributors to visual disability, especially when accounting for posterior corneal backscatter. Corneal backscatter is a driver of characteristic visual disability in Fuchs dystrophy. Comprehensive assessments of morphology and direct quantification of disease-related disability may help identify the best candidates for endothelial keratoplasty.