Abstract:

 Objective   Riboflavin / ultraviolet-A induced cross-linking can markedly improve the biomechanical parameters of the cornea. We studied the biomechanical properties of rabbit corneas with epithelium after cross-linking, and made a comparison with the traditional method which removes the epithelium during cross-linking. Methods   Sixty eyes of 30 rabbits were randomly divided into two groups: one eye of each rabbit served as the control group and the other as the experimental group. In the experimental group, the cornea was cross-linked either with intact epithelium or with epithelium removed. All rabbits were immediately sacrificed after irradiation, followed by harvesting corneal strips for biomechanical evaluation. Results   After cross-linking, corneal thickness was thicker in the experimental group than in the control group(P＜0.05), however there was no difference between the two experimental groups(P=0.098). The maximum stress of the corneal strips without epithelium were obviously higher than the control group (P＜0.05), but there was no difference between the two experimental groups (P=0.058). Considering the Young′s modulus E, the value was higher in the deepithelium group than in the group with epithelium, and higher than the control group (P＜0.05). Conclusions   Riboflavin/ultraviolet-A induced cross-linking can enhance the maximal stress and biomechanical stiffness of the cornea, and the effect is greater in the de-epithelium group than in the group with epithelium.

Key words: UVA; Cross-linking; Corneal epithelium; Biomechanics