Nonlinear optical collagen cross-linking and mechanical stiffening: a possible photodynamic therapeutic approach to treating corneal ectasia

Dongyul Chai; Tibor Juhasz; Donald J. Brown; James V. Jester

doi:10.1117/1.JBO.18.3.038003

20 March 2013 Nonlinear optical collagen cross-linking and mechanical stiffening: a possible photodynamic therapeutic approach to treating corneal ectasia

Dongyul Chai, Tibor Juhasz, Donald J. Brown, James V. Jester

Author Affiliations +

Journal of Biomedical Optics, Vol. 18, Issue 3, 038003 (March 2013). https://doi.org/10.1117/1.JBO.18.3.038003

Abstract

In this study we test the hypothesis that nonlinear optical (NLO) multiphoton photoactivation of riboflavin using a focused femtosecond (FS) laser light can be used to induce cross-linking (CXL) and mechanically stiffen collagen as a potential clinical therapy for the treatment of keratoconus and corneal ectasia. Riboflavin-soaked, compressed collagen hydrogels are cross-linked using a FS laser tuned to 760 nm and set to either 100 mW (NLO CXL I) or 150 mW (NLO CXL II) of laser power. FS pulses are focused into the hydrogel using a 0.75 NA objective lens, and the hydrogel is three-dimensionally scanned. Measurement of hydrogel stiffness by indentation testing show that the calculated elastic modulus (E ) values are significantly increased over twofold following NLO CXL I and II compared with baseline values (P<0.05 ). Additionally, no significant differences are detected between NLO CXL and single photon, UVA CXL (P<0.05 ). This data suggests that NLO CXL has a comparable effect to conventional UVA CXL in mechanically stiffening collagen and may provide a safe and effective approach to localize CXL at different regions and depths within the cornea.

CC BY: © The Authors. Published by SPIE under a Creative Commons Attribution 4.0 Unported License. Distribution or reproduction of this work in whole or in part requires full attribution of the original publication, including its DOI.

Citation Download Citation

Dongyul Chai, Tibor Juhasz, Donald J. Brown, and James V. Jester "Nonlinear optical collagen cross-linking and mechanical stiffening: a possible photodynamic therapeutic approach to treating corneal ectasia," Journal of Biomedical Optics 18(3), 038003 (20 March 2013). https://doi.org/10.1117/1.JBO.18.3.038003

Published: 20 March 2013

ACCESS THE FULL ARTICLE

JOURNAL ARTICLE
9 PAGES

DOWNLOAD PAPER SAVE TO MY LIBRARY