Baseline Characteristics of 1976 Patients With Ectatic Corneal Disorders at a Single Center From 2010 to 2021: A Cross-Sectional Study of the Homburg Keratoconus Center

Abstract

Objectives: The study objective was to analyze the baseline characteristics of keratoconus (KC) patients at the Homburg Keratoconus Center from 2010 to 2021. Methods: This cross-sectional study included 3,674 eyes, with analysis of demographics, clinical findings, visual function, endothelial measurements, and topographic, tomographic, and corneal biomechanical data from the first visit. Results: Mean patient age was 36.3±13.8 years. The mean uncorrected distance visual acuity in log of minimal angle of resolution was 0.60 (20/80, Snellen equivalent), and the corrected mean was 0.3 (20/40). Of 1976 patients, 48.9% reported eye rubbing. Mean values (ranges) were 49.4±6.3 (36.3–78.0) D for steep keratometry, 462.4±66.0 (48.0–659.0) μm for thinnest corneal thickness, 9.7±8.7 (−0.5 to 88.8) for Belin/Ambrósio enhanced ectasia total deviation, 0.8±0.4 (0.0–1.0) for the Corvis biomechanical index, 0.9±0.2 (0.0–1.0) for the tomographic biomechanical index, 0.1±0.5 (−0.9 to 2.0) for the KC match index, 8.3±1.8 (2.2–17.7) mm Hg for corneal hysteresis, 7.1±2.2 (0.0–17.0) mm Hg for corneal resistance factor, and 2,562.9±326.3 (1,011–3,937) cells/mm2 for endothelial cell density. The average ABCDE KC stage was A2B3C1D1E2. Distance-corrected visual acuity correlated strongly with topometric, tomographic, and biomechanical data (P<0.001). Conclusions: This comprehensive description of baseline features of KC patients at a tertiary center provides a reference for further longitudinal and international multicentric studies.

Keratectasia severity staging and progression assessment based on the biomechanical E-staging

“…It was shown that the most severe KC stage was set by parameter “B” followed by “E”, “A” and “C” [ 40 ]. As posterior elevation data and thinnest corneal thickness were diagnostic criteria in the selection of KC corneas for the study population used to create the BEST and also in Sideroudi's baseline HKC study [ 27 ], these are only frequency data and one cannot infer from this in principle that stages of “B” are generally more advanced than “E” or “A” in every KC [ 40 ]. The resulting BEST is meant to be an addition to the tomographic ABCD KC staging system that was published previously as it supplements biomechanical severity information for keratectasia.…”

“…A baseline analysis of characteristics and application of the ABCD staging system on a large cohort of KC patients within the HKC revealed (1) more male (73%) than female (27%) KC patients, (2) more advanced posterior (“B”) than anterior (“A”) radius of curvature stages, (3) 8% to suffer from atopic dermatitis and 40% from allergies [ 20 ], (4) a mean ABCDE stage of A2B3C1D1E2 and (5) a mean Belin-Ambrósio deviation (BAD) index of 9.7 ± 8.7 among 3674 KC corneas [ 27 ].…”