New severity grading system for Fuchs endothelial corneal dystrophy using anterior segment optical coherence tomography

Abstract

Purpose To report a new severity grading system for Fuchs endothelial corneal dystrophy (FECD) using anterior segment optical coherence tomography (AS‐OCT). Methods This observational case series included 75 eyes of 43 patients with FECD and 33 eyes of 33 healthy subjects. Pachymetry and posterior elevation maps were used to determine the AS‐OCT‐based grading scores. FECD severity was graded from 0–3 as follows: 0, normal; 1, guttae only; 2, stromal oedema; and 3, epithelial and stromal oedema. We further investigated the central corneal thickness (CCT), thinnest corneal thickness (TCT), anterior and posterior best‐fit spheres (BFS), and the distance between the central cornea and the thinnest point. Results Thirty‐three eyes were graded as 0, four as 1, thirteen as 2, fourteen as 3, twenty‐nine as 4, eleven as 5 and four as 6 by the modified Krachmer grade. Thirty‐three, 41, 30 and 4 eyes were graded as 0, 1, 2 and 3, respectively, by the AS‐OCT‐based grading system. The inter‐observer agreement was 100% for the AS‐OCT‐based grading system. The CCT, TCT, posterior BFS, and distance between the central cornea and thinnest point were significantly different between AS‐OCT‐based grades (p = 0.0001, 0.0001, 0.0036 and 0.0001, respectively). Anterior BFS was not significantly different with the AS‐OCT‐based grades (p = 0.1184). Conclusion We devised a new severity grading using only objective evaluation and quantitatively demonstrated corneal thickening, predominant flattening of the posterior corneal surface compared with the anterior surface, and displacement of the thinnest point away from the central cornea with FECD progression.

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

“…They demonstrated a corneal thickening, predominant posterior corneal flattening, and displacement of the thinnest point of the cornea with FECD progression. 21 This is comparable with the grading system described by Patel et al 4,5 using Scheimpflug imaging and used in this study. Wertheimer et al 16 used corneal optical density anterior segment OCT as an objective value for corneal changes in FECD.…”

“…Recently, Yasukura et al 21 reported on a new severity grading system for FECD using anterior segment OCT. They demonstrated a corneal thickening, predominant posterior corneal flattening, and displacement of the thinnest point of the cornea with FECD progression.…”

Imaging Fuchs Endothelial Corneal Dystrophy in Clinical Practice and Clinical Trials

“…In preliminary work, similar findings have been described in posterior elevation and pachymetry maps of FECD corneas. 11…”

Optical Coherence Tomography for Diagnosis and Treatment of Corneal Diseases

“…ОКТ позволяет оценить толщину и структурные изменения эпителия, стромы и ДМ. Данный метод обеспечивает дифференциальную диагностику между транзиторным помутнением роговицы, обусловленным разреженностью ее стромальных волокон на фоне выраженного отека ткани, и необратимым снижением прозрачности роговицы, проявляющимся на ОКТизображении в виде участков с повышенной светоотражающей способностью [37,38]. Наличие последних может быть одной из причин низкой остроты зрения после эндотелиальной кератопластики [39].…”