Purpose: To describe the diagnostic accuracy of 3-dimensional (3D) endothelium–Descemet's membrane complex thickness (En–DMT) in Fuchs’ endothelial corneal dystrophy (FECD) and determine its potential role as an objective index of disease severity. Design: Observational case-control study. Participants: One hundred four eyes of 79 participants (64 eyes of 41 FECD patients and 40 eyes of 38 healthy controls). Methods: All participants received high-definition OCT imaging (Envisu R2210; Bioptigen, Buffalo Grove, IL). Fuchs’ endothelial corneal dystrophy was classified clinically into early-stage (without edema) and late-stage (with edema) disease. Automatic and manual segmentation of corneal layers was performed using a custom-built segmental tomography algorithm to generate 3D maps of total corneal thickness (TCT) and En–DMT of the central 6-mm cornea. Regional En–DMT, regional TCT, and central-to-peripheral total corneal thickness ratio (CPTR) were evaluated and correlated to the clinical severity of FECD. Intraclass correlation coefficients (ICCs) and Bland-Altman plots were used to assess the reliability of the repeated measurements in all eyes. Main Outcome Measures: Central-to-peripheral total corneal thickness ratio and average En–DMT and TCT of central, paracentral, and peripheral regions. Results: In FECD, a significant increase in En–DMT, CPTR, and TCT was found compared to controls (P < 0.001). For identifying FECD, average En–DMT of paracentral and peripheral regions achieved 94% sensitivity and 100% specificity (cutoffs, 19 μm and 20 μm, respectively), whereas CPTR showed 94% sensitivity with a 73% specificity (cutoff, 0.97). Regarding early-stage FECD, average En–DMT of central zones achieved 92% sensitivity and 97% specificity (cutoff, 18 μm), whereas CPTR showed 90% sensitivity and 88% specificity (cutoff, 0.97). The average En–DMT of central, paracentral, and peripheral regions was correlated highly with FECD clinical stage (Spearman's ρ = 0.813, 0.793, and 0.721, respectively; all P < 0.001), compared with CPTR and mean TCT of paracentral zones (0.672 and 0.481, respectively; P < 0.001). The ICC values ranged from 0.98 (En–DMT) to 0.99 (TCT) with a good agreement between the automatic and manual measurements. Conclusions: Regional 3D En–DMT is a novel diagnostic tool of FECD that can be used to quantify the disease severity with excellent reliability.
ASJC Scopus subject areas