Scheimpflug Versus Optical Coherence Tomography to Detect Subclinical Corneal Edema in Fuchs Endothelial Corneal Dystrophy

Abstract

The purpose of this research was to compare the ability of Scheimpflug and anterior segment optical coherence tomography (OCT) in detecting subclinical corneal edema in patients with Fuchs endothelial corneal dystrophy (FECD) without clinical corneal edema. Methods:In this single-center, consecutive case series, 47 eyes of 29 patients with FECD were analyzed. The main outcome measures were anterior/posterior keratometry and central/thinnest corneal thickness. The criteria for subclinical corneal edema were loss of regular isopachs, displacement of the thinnest point of the cornea, and presence of posterior surface depression. Tomographic analyses were performed using Scheimpflug imaging (Pentacam HR) and OCT (anterior segment swept-source optical coherence tomography). Results:The measurement of the continuous variables revealed a significant difference between the 2 devices. The anterior curvature was steeper and the posterior curvature was flatter when measured with OCT (P , 0.001). The OCT showed a lower central corneal thickness and thinnest corneal thickness (P , 0.001). The agreement between both devices to detect subclinical corneal edema was high.The interdevice reliability for loss of parallel isopachs as measured by Cohen kappa coefficient was 0.84; for the displacement of the thinnest point of the cornea, it was 0.6, and for the focal posterior corneal surface depression, it was 0.62. Subclinical corneal edema was detected in 72.3% of the patients with both devices. In only 2 cases (4.3%), subclinical corneal edema was detected by one of the devices.Conclusions: Scheimpflug and OCT imaging were both able to detect tomographic patterns of subclinical corneal edema. Therefore, both devices can help decision-making, favoring early endothelial keratoplasty in symptomatic patients with FECD without clinical corneal edema.

Refractive outcomes after DMEK: meta-analysis

“…39 Given the change in the posterior corneal curvature after DMEK, studies have shown that preoperative tomographic analysis may aid in assessing the risk of postoperative hyperopic surprise in patients with FECD. 31,40,[48][49][50][51] The Pentacam Q value is a widely used parameter of the corneal surface profile that can be zero (spherical cornea), positive (oblate cornea), or negative (prolate cornea). Therefore, in healthy eyes, the posterior surface usually carries a negative Q value, whereas in eyes with a compromised endothelium the edematous changes typically lead to a positive Q value.…”

Comparison of corneal tomography using a novel swept-source optical coherence tomographer and rotating Scheimpflug system in normal and keratoconus eyes: repeatability and agreement analysis

“…The findings of the repeatability of Kmax were equivalent to the findings of Matar et al comparing both technologies. Moreover, a steeper anterior corneal curvature, a flatter posterior curvature, and a thinner corneal thickness were determined by SS-OCT (ANTERION) in comparison to RSC in FECD eyes [ 43 ].…”

Automatic Quantitative Assessment of Lens Opacities Using Two Anterior Segment Imaging Techniques: Correlation with Functional and Surgical Metrics

“…However, one should consider that maximum imaging depth depends on numerous factors such as lens opacity, pupil size, tear film quality and number of B-Scan averaging; hence, an absolute value cannot be determined. It should also be noted that the Pentacams’ primary objective is corneal diagnostics [ 32 , 33 , 34 , 35 ]. Therefore, one may expect that an SS-OCT device enables a better view of the entire lens thickness, making it difficult to compare the lenticular opacity between both systems.…”