Assessing Corneal Tomographic Changes in Fuchs Endothelial Corneal Dystrophy Over 1 year: Scheimpflug Versus Anterior Segment Optical Coherence Tomography.

Abstract

The objective of this study was to compare the capacity of anterior segment optical coherence tomography (AS-OCT) and Scheimpflug camera in detecting tomographic changes over 1 year in a cohort of patients with Fuchs endothelial corneal dystrophy. We conducted a single-center prospective study which consisted of 2 identical visits spaced 1 year apart. At each visit, tomographic analyses were performed using Scheimpflug imaging (Pentacam HR, Oculus) and swept source AS-OCT (Casia SS-1000 Tomey). The resulting images were analyzed by 3 experienced independent observers. The main outcome was the agreement between the 2 devices for detecting subclinical corneal edema, as assessed using the interdevice reliability measured by the Cohen kappa coefficient. The criteria for subclinical edema were the presence of irregular isopachs, displacement of the thinnest point, and presence of posterior surface depression. We analyzed 129 eyes of 81 patients with good quality images for both devices. The overall agreement between the 2 devices to detect subclinical edema was good, but the performance was significantly different for 2 parameters (thinnest point displacement and posterior depression). The interdevice reliability was 0.84 for the loss of parallel isopachs, 0.55 for the displacement of the thinnest point, and 0.40 for the focal posterior corneal surface depression. Corneal tomographic features of Fuchs endothelial corneal dystrophy can be easily quantified in clinical routine and clinical research by AS-OCT and Scheimpflug imaging, but both are not fully interchangeable. A longitudinal follow-up should always be done with the same device. Neither appears to be more sensitive than the other for detecting minimal changes over 12 months.