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BioMed Research International
Volume 2013 (2013), Article ID 624563, 6 pages
Research Article

Role of Corneal Epithelium in Riboflavin/Ultraviolet-A Mediated Corneal Cross-Linking Treatment in Rabbit Eyes

1Department of Ophthalmology, Shandong Provincial Hospital Affiliated to Shandong University, No. 324, Jing 5 Road, Jinan, Shandong 250021, China
2Department of Ophthalmology, Affiliated Hospital of Weifang Medical College, Weifang, Shandong 261000, China
3Department of Visual Sciences and Ophthalmology, The Chinese University of Hong Kong, Shatin, Hong Kong
4Centre for Eye Research Australia, University of Melbourne, Melbourne, VIC, Australia

Received 15 April 2013; Accepted 11 June 2013

Academic Editor: Vasilios F. Diakonis

Copyright © 2013 Xiangchen Tao et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.


Purpose. To evaluate the role of corneal epithelium in riboflavin/ultraviolet-A (UVA) mediated corneal collagen cross-linking treatment. Methods. Fifty New Zealand rabbits were divided into 5 groups: UVA treatment with or without corneal epithelium, UVA+riboflavin treatment with or without corneal epithelium, and control without any treatment. All rabbits were sacrificed after irradiation and subsequently 4 mm × 10 mm corneal strips were harvested for biomechanical evaluation. Results. UVA irradiation alone did not enhance the maximal stress and Young’s modulus of corneal specimens with (3.15 ± 0.56 mpa, 1.00 ± 0.09 mpa) or without (3.53 ± 0.85 mpa, 0.94 ± 0.21 mpa) the corneal epithelium, compared to specimens in the control group (4.30 ± 0.68 mpa, 1.03 ± 0.24 mpa). However, UVA irradiation combined with riboflavin significantly increased the maximal stress and Young’s modulus of corneal specimens with (5.27 ± 1.09 mpa, 1.23 ± 0.23 mpa, ) or without (7.16 ± 1.88 mpa, 1.42 ± 0.16 mpa, ) corneal epithelium when compared to the control group. The maximal stress and Young’s modulus of cornea in UVA+riboflavin and “epithelium-off” group were 35.9% and 15.4% higher compared to the UVA+riboflavin and “epithelium-on” group, respectively ( ). Conclusions. Our study shows that UVA+riboflavin treatment significantly affects the biomechanical properties of the cornea with and without epithelial removal. However, corneas without epithelium seem to benefit more compared to corneas with the epithelium.