Determining subclinical edema in fuchs endothelial corneal dystrophy: Scheimpflug versus anterior segment‐optical coherence tomography

Abstract

AbstractPurpose: To compare the capacity of anterior segment optical coherence tomography (AS‐OCT) and Scheimpflug camera in detecting subclinical corneal edema in patients with Fuchs endothelial corneal dystrophy (FECD).Methods: 177 eyes of 103 patients with FECD without obvious corneal edema were included and analysed in this single‐center prospective study (NCT03974230). Tomographic analyses were performed successively using Scheimpflug imaging (Pentacam HR, Oculus) and a swept‐source AS‐OCT (Casia SS‐1000 Tomey). All measurements were performed more than 4 hours after awaking to have a stabilized corneal thickness. The resulting images were analysed by two experienced independent observers. AS‐OCT and Scheimpflug images were analysed independently. The main outcome was the agreement between the ability of the two devices to detect subclinical corneal edema, assessed using inter‐device reliability measured by the Cohen kappa statistic. The criteria for subclinical corneal edema were as follows: the presence of irregular isopachs, displacement of the thinnest point of the cornea, and the presence of posterior surface depression.Results: The agreement between the two devices to detect subclinical corneal edema was high. The inter‐device reliability for loss of parallel isopachs, as measured by the Cohen kappa coefficient, was 0.75; for the displacement of the thinnest point of the cornea, it was 0.65; and for the focal posterior corneal surface depression, it was 0.53. The inter‐device reliability for the detection of subclinical corneal edema was 0.70. Subclinical corneal edema was detected in 77% of cases analysed with both devices.Conclusions: Subclinical corneal edema in patients with FECD can be detected by AS‐OCT as well as by Scheimpflug imaging. Both devices can facilitate surgical decision‐making when evaluating the risk of corneal edema after cataract surgery in eyes with FECD.