Posters

In vivo early corneal biomechanical changes after collagen cross-linking in patients with progressive keratoconus

Poster Details

First Author: R.Vinciguerra ITALY

Co Author(s):    A. Tzamalis   V. Romano   E. Arbabi   M. Batterbury   S. Kaye        

Abstract Details

Purpose:

To report early corneal biomechanical changes after corneal collagen cross-linking (CXL) in progressive keratoconus and to evaluate whether there is a correlation between the stiffening effect measured with the Corvis ST (OCULUS Optikgeräte GmbH; Wetzlar, Germany) Dynamic Corneal Response Parameters (DCRs) and the depth of the demarcation line evaluated with anterior segment OCT (AS-OCT).

Setting:

Department of Corneal and External Eye Diseases, St. Paul’s Eye Unit, Royal Liverpool University Hospital, Liverpool, UK

Methods:

Eighty-nine eyes of 76 patients treated with CXL for progressive KC were included. DCRs obtained with the Corvis ST and Pentacam tomography were assessed at baseline (day of CXL) and after one month of follow-up. Demarcation line (DL) after CXL was assessed 4 weeks postop and it was defined as the posterior edge of the white-looking line present in the mid-stroma.

Results:

Comparative analyses showed a rise of corneal stiffness demonstrated by a significant increase of Stiffness Parameter A1 (SP-A1) and Highest Concavity (SP-HC) and a significant decrease of Inverse Concave Radius (1/R), and Deformation Amplitude Ratio (DAratio) (all p<0.05). Furthermore, there was no significant correlation between the stiffening effect (measured as delta DCRs) and the depth of the demarcation line in any of the DCRs evaluated (p=0.575 for Stiffness Parameter A1 (SP-A1), 0.729 for Inverse concave radius (1/R)).

Conclusions:

This study shows that the new DCRs by the Corvis ST are able to detect early changes in biomechanics following CXL and those are measurable before corneal shape modifications take place. The study also proves that there is no significant correlation between the stiffening effect and the depth of the demarcation line. Based on these results we suggest the use of these metrics to assess the early efficacy of cross-linking.

Financial Disclosure:

receives consulting fees, retainer, or contract payments from a company producing, developing or supplying the product or procedure presented