Transepithelial versus Epithelium off Crosslinking for Treating Keratoconus among Jordanians

Khalid Al Zubi1, *, Yaser Albakar2, Rana Nasser2
1 Faculty of Medicine, Mutah University, Al-Karak, Jordan
2 Saraya Eye Centre, Amman, Jordan



The progression of keratoconus is stabilized with the help of corneal collagen cross-linking (CXL) supported through photosynthesized riboflavin.


This study aims to compare the effectiveness of the transepithelial procedure and epithelium off procedure of corneal collagen crosslinking among keratoconus patients in Jordan.


The study recruited 80 patients suffering from progressive keratoconus, from a tertiary care setting in Jordan. These participants were randomly divided into two groups; group 1 with 40 participants subjected to transepithelial (Corneal collagen cross-linking) CXL; and 40 participants in group 2 received conventional epithelium off CXL.


Improvement was observed in the mean contact lens, which corrected distance visual acuity (CDVA) from logMAR 0.332 ± 0.09 (group 1), 0.35 ± 0.09 (group 2) to 0.241 ± 0.07 (group 1), 0.21 ± 0.07 (group 2), respectively at the end of follow-up (12 months). The mean pachymetry improved from 429.81 ± 18.96 μm (group 1), 430.08 ± 17.05 μm (group 2) to 436.5 ± 15.49 μm (group 1), 436.44 ± 12.53 μm (group 2), respectively, after twelve months. Additionally, the mean Sim K astigmatism declined from 7.0 ± 2.0 (group 1), 6.73 ± 1.98 (group 2) to 5.97 ± 1.88 (group 1), 5.53 ± 0.08 (group 2) respectively at twelve months post-treatment. Majority of the patients in group 2 experienced more pain as compared to group 1 participants.


The effectiveness of a cross-linking procedure related to keratometry readings and corneal thickness showed that conventional (epithelium off) CXL method is more effective than transepithelial CXL.

Keywords: Keratoconus, Collagen, Cornea, Crosslinking, Visual Acuity, Keratoplasty.

Abstract Information

Identifiers and Pagination:

Year: 2019
Volume: 13
Publisher Item Identifier: EA-TOOPHTJ-2018-39

Article History:

Received Date: 7/11/2018
Revision Received Date: 24/12/2018
Acceptance Date: 18/1/2019
Electronic publication date: 07/02/2019
Collection year: 2019

© 2019 Al Zubi et al.

open-access license: This is an open access article distributed under the terms of the Creative Commons Attribution 4.0 International Public License (CC-BY 4.0), a copy of which is available at: ( This license permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.

Correspondence: Address correspondence to this author at the Faculty of Medicine, Mutah University, Al-Karak, Postal Address: P. O. Box 1342 Aljubaiha, Amman 11941, Jordan; Tel: 00962797950830; E-mail: