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Structural and Biomechanical Effects of Photooxidative Collagen Cross-Linking with Photosensitizer Riboflavin and 370 nm UVA Light on Human Corneoscleral Tissues

Published online by Cambridge University Press:  06 June 2013

Samjin Choi
Department of Biomedical Engineering & Healthcare Industry Research Institute, Kyung Hee University, Seoul 130-701, Korea Department of Medical Engineering, Kyung Hee University, Seoul 130-701, Korea
Jae-Ho Shin
Department of Ophthalmology, Kyung Hee University, Seoul 130-701, Korea
Youjin Cheong
Department of Biomedical Engineering & Healthcare Industry Research Institute, Kyung Hee University, Seoul 130-701, Korea
Kyung-Hyun Jin
Department of Ophthalmology, Kyung Hee University, Seoul 130-701, Korea
Hun-Kuk Park*
Department of Biomedical Engineering & Healthcare Industry Research Institute, Kyung Hee University, Seoul 130-701, Korea Department of Medical Engineering, Kyung Hee University, Seoul 130-701, Korea
*Corresponding author. E-mail:
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This study quantitatively investigated the immediate effects of a photooxidative collagen cross-linking treatment with photosensitizer riboflavin (RF) and 370 nm UVA light in in vitro human corneoscleral collagen fibrils using histology, thickness, scanning electron microscopy, and atomic force microscopy analyses. Twenty 8 × 2 mm corneoscleral strips were dissected sagittally from donor tissue using a scalpel. Four parameters were investigated, including the density, thickness, adhesion force, and stiffness of corneoscleral tissues before and after the collagen cross-linking treatment. The RFUVA-catalyzed collagen cross-linking treatment led to an increase in the density of both corneal (8%) and scleral (23%) stromal collagens. However, there was no difference in corneoscleral thickness. Furthermore, RFUVA-catalyzed collagen cross-linking treatment led to an increased biomechanical response of corneosclera: 25 and 8% increases in corneoscleral stiffness, and 24 and 22% increases in corneoscleral adhesion force. The collagen cross-linking treatment through RF-sensitized photoreaction may cause structural and biomechanical changes in the collagen fibril network of the cornea and the sclera. This is due to narrowing of the interfibrillar spacing and the stromal edema.

Biological Applications
Copyright © Microscopy Society of America 2013 

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