Changes in corneal biomechanical parameters in keratoconus eyes with various severities after corneal cross-linking (CXL): A comparative study

Mohammad-Reza Sedaghat, Hamed Momeni-Moghaddam, Haleh Kangari, Azar Moradi, Reyhaneh Akbarzadeh, Shehzad A Naroo

Research output: Contribution to journalArticlepeer-review


Objectives To compare changes in corneal biomechanical parameters one year after corneal cross-linking (CXL) in keratoconus (KCN) eyes of different severities. Methods Seventy-five eyes with mild, moderate, and severe grades of KCN (n = 24, 31, and 20 eyes, respectively) that were treated with CXL, based upon the standard Dresden protocol, were included. The corneal biomechanical assessment was performed using Corvis ST and Ocular Response Analyzer (ORA). Changes in Corvis's dynamic corneal response (DCR) parameters and ORA's derived parameters (corneal hysteresis (CH), and corneal resistance factor (CRF)) were assessed whilst the corneal thickness and intraocular pressure were considered as covariates. Results There was no statistically significant difference in the corneal biomechanical parameters obtained using both devices after surgery separately in different KCN grades, except for the deformation amplitude (DA) in the severe KCN group (P = 0.017). Changes in the classic parameters of the highest concavity phase of Corvis ST (peak distance, radius, and DA) were more positive and in the newer parameters (integrated inverse radius (IIR), deformation amplitude ratio (DAR)) more negative in the severe group compared to the other groups. Also, the mean change in CH (P = 0.710), and CRF (P = 0.565), showed a negative shift in higher grades of KCN; however, there was no significant difference in the mean changes of all parameters between different groups. (P > 0.05) Conclusions Similar changes in the Corvis ST and ORA parameters in mild, moderate, and severe KCN indicate biomechanical stability and the effective role of CXL in stopping the progressive nature of keratoconus in eyes of varying severities one year after CXL.
Original languageEnglish
Pages (from-to)2114-2122
Number of pages9
JournalEuropean Journal of Ophthalmology
Issue number6
Early online date27 Apr 2023
Publication statusPublished - Nov 2023

Bibliographical note

Copyright © The Author(s) 2023. This accepted manuscript version is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License [].


  • Keratoconus
  • corneal biomechanics
  • corneal cross-linking
  • hysteresis
  • severity


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