Secondary Logo

Institutional members access full text with Ovid®

Comparison of Corneal Collagen Cross-Linking Protocols Measured With Scheimpflug Tomography

Shajari, Mehdi, MD; Sowwa, Gabriela; Steinwender, Gernot, MD; Hofmann, Christian, MD, FEBO; Pahlitzsch, Marie-Luise, MD; Petermann, Kerstin, MSc; Kohnen, Thomas, MD, PhD, FEBO

doi: 10.1097/ICO.0000000000001600
Clinical Science

Purpose: To evaluate the effectiveness of corneal collagen cross-linking with Dresden and accelerated protocols to treat keratoconus by Scheimpflug tomography.

Methods: Fifty-eight eyes with manifest keratoconus were measured preoperatively at least twice with the Pentacam. The difference of relevant variables for keratoconus progression (eg, D value, thinnest pachymetry, Kmax) was established. After evident progression, patients underwent corneal cross-linking (29 eyes with the Dresden protocol and 29 eyes with the accelerated protocol). Postoperatively, variables used for defining manifest progression were compared again by measuring the difference between 2 measurements.

Results: Preoperatively, the mean D value was 9.6 ± 4.8 for the Dresden cohort and 8.3 ± 5.1 for the accelerated cohort. There was no significant difference between both cohorts in terms of the mean preoperative difference in the D value (0.59 ± 1.7 for the Dresden cohort vs. 0.4 ± 1.49, P = 1). Postoperatively, however, a significant difference (P < 0.01 for the accelerated corhort) was found (Dresden: −0.47 ± 0.88 vs. accelerated: 0.04 ± 0.67). Regression analysis showed that keratoconus progression was significant in both study groups preoperatively (with a significant reduction of corneal thickness and increase in the D value). Postoperative data show an improvement in all observed keratoconus indices in both study groups and stagnation in progression for the accelerated cohort, P = 0.774, for the D value and a regression in manifestation for the Dresden cohort (decrease in the D value, P < 0.01).

Conclusions: Before operative intervention, Scheimpflug imaging showed signs of a progressive disease in all eyes. Both conventional Dresden protocol and accelerated pulsed corneal collagen cross-linking techniques effectively stopped this progression.

Department of Ophthalmology, Goethe University, Frankfurt am Main, Germany.

Correspondence: Thomas Kohnen, MD, PhD, FEBO, Department of Ophthalmology, Goethe University, Theodor-Stern-Kai 7, 60590 Frankfurt am Main, Germany (e-mail:

M. Shajari: Oculus; T. Kohnen: Consultant or Advisory Board—Abbott, Alcon, Geuder, Oculus, Santen, Schwind, Staar, TearLab, Thea Pharma, Thieme Compliance, Ziemer, Zeiss; Research Funding—Abbott, Alcon, Hoya, Oculentis, Oculus, Schwind, Zeiss.

Received November 30, 2017

Received in revised form February 08, 2018

Accepted February 18, 2018

Copyright © 2018 Wolters Kluwer Health, Inc. All rights reserved.