Long-term biomechanical properties of rabbit cornea after photodynamic collagen crosslinking
Long-term biomechanical properties of rabbit cornea after photodynamic collagen crosslinking
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DOI：
10.1111/j.1755-3768.2008.01190.x
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发表时间：
2009-02-01
影响因子：
3.4
通讯作者：
Iomdina, Elena
中科院分区：
文献类型：
--
作者：
Wollensak, Gregor;Iomdina, Elena
光动力核黄素/紫外线-A（UVA）诱导的胶原交联，其使人角膜的生物力学刚度增加约300%，最近已被引入作为进行性圆锥角膜的可能治疗。本研究是为了评价这种新的交联治疗作为其临床成功的必要先决条件的长期生物力学效应。对侧眼作为对照。在去除中央7 mm的上皮后，用光敏剂核黄素和UVA照射处理角膜30分钟，使用370 nm UVA双二极管，辐照度为3 mW/cm（2）。分别在给药后即刻以及3个月和8个月时处死每组3只动物。使用微机控制的生物材料测试仪在4 × 10-mm角膜条上进行生物力学应力-应变测量，经处理的兔角膜的角膜厚度为408 ± 20 μ m。极限应力持续且显着增加（69.7-106.0%），杨氏弹性模量（78.4-87.4%）和极限应变降低（0.57-78.4%）。核黄素/UVA诱导的胶原交联连接导致生物力学刚度的长期增加，其随时间保持稳定。这些数据支持我们以前的长期临床观察，并希望这种新的治疗方法将最终阻止进行性圆锥角膜。
Photodynamic riboflavin/ultraviolet-A (UVA)-induced collagen cross-linking, which increases the biomechanical stiffness of the human cornea by about 300%, has been introduced recently as a possible treatment for progressive keratoconus. The present study was undertaken to evaluate the longterm biomechanical effects of this new cross-linking treatment as a necessary prerequisite to its clinical success.The corneas of the left eyes of nine male rabbits were cross-linked. The contralateral eyes served as controls. After removal of the central 7 mm of the epithelium, the corneas were treated with the photosensitizer riboflavin and UVA irradiation for 30 mins with an irradiance of 3 mW/cm(2) using a 370-nm UVA double diode. Groups of three animals were killed immediately after treatment and at 3 and 8 months, respectively. Biomechanical stress-strain measurements were performed using a microcomputer-controlled biomaterial tester on 4 x 10-mm corneal strips.Corneal thickness in the treated rabbit cornea was 408 +/- 20 mu m. A constant and significant increase in ultimate stress (of 69.7-106.0%), Young's modulus of elasticity (of 78.4-87.4%) and a decrease in ultimate strain (of 0.57-78.4%) were found over a time period of up to 8 months after cross-linking treatment.Riboflavin/UVA-induced collagen cross-linking leads to a longterm increase in biomechanical rigidity which remains stable over time. These data support our previous longterm clinical observations and give hope that this new treatment will halt progressive keratoconus definitively.