Evaluation of Corneal Biomechanical Behavior in-vivo for Healthy and Keratoconic Eyes Using the Stress-Strain Index.



Padmanabhan, Prema, Lopes, Bernardo T ORCID: 0000-0002-8489-3621, Eliasy, Ashkan ORCID: 0000-0002-4473-1900, Abass, Ahmed, Vinciguerra, Riccardo, Vinciguerra, Paolo, Ambrósio, Renato and Elsheikh, Ahmed ORCID: 0000-0001-7456-1749
(2022) Evaluation of Corneal Biomechanical Behavior in-vivo for Healthy and Keratoconic Eyes Using the Stress-Strain Index. Journal of cataract and refractive surgery.

[img] Text
Evaluation of Corneal Biomechanical Behavior in-vivo for Healthy and Keratoconic Eyes Using the Stress-Strain Index_Manuscript_Accepted.docx - Accepted Version
Access to this file is embargoed until 23 March 2023.
Available under License Creative Commons Attribution Non-commercial.

Download (81kB)

Abstract

To evaluate corneal material properties characteristics in healthy and keratoconic patients utilising the stress-strain index (SSI). Vincieye Clinic in Milan, Italy, and Instituto de Olhos Renato Ambrósio in Rio de Janeiro, Brazil. Retrospective observational cross-sectional study. Records of 1,221 patients were divided into 3 groups: healthy corneas (n=728), bilateral keratoconus (KC, n=388), and very asymmetric ectasia (VAE, n=105) when patients presented one eye with clinical ectasia and the fellow-eye with normal topography (VAE-NT). All patients were examined with Pentacam HR and Corvis ST (both, Oculus, Wetzlar, Germany). KC cases severity were stratified according to Pentacam's topographic keratoconus classification. The SSI distribution across the different groups and its correlation with age, biomechanically corrected intraocular pressure (bIOP) and central corneal thickness (CCT) were assessed. There was a significant difference between healthy and each of the keratoconic groups (p<0.001) and a progressive reduction in SSI was observed across the groups. There was a significant correlation between SSI and age in all groups (p<0.010), but KC severe (p=0.361). No correlation between SSI and bIOP or CCT was observed in all KC subgroups and VAE-NT (p>0.050). Among healthy eyes, there was only a mild correlation between SSI and bIOP (R=0.12, p=0.002) and CCT (R=0.13, p=0.001). This study estimates with a new method the in vivo corneal material properties in healthy and keratoconus patients. The SSI showed a progressive deterioration within the advance in disease stages, while being relatively independent of bIOP and CCT but positively correlated with age.

Item Type: Article
Divisions: Faculty of Science and Engineering > School of Engineering
Depositing User: Symplectic Admin
Date Deposited: 22 Mar 2022 08:10
Last Modified: 10 Sep 2022 08:23
DOI: 10.1097/j.jcrs.0000000000000945
URI: https://livrepository.liverpool.ac.uk/id/eprint/3151240