核黄素/紫外线A诱导的胶原交联对兔和人巩膜生物力学性能的影响

摘要

目的 比较兔和人巩膜核黄素/紫外线A交联前后的生物力学性能.方法 实验研究.取8只成年新西兰大白兔和8只新鲜离体成人眼,沿矢状位方向平均分为两半,一半作为对照,一半作交联试件.交联的参数设置:0.1％核黄素溶液滴眼,每3 min 1次,共5次;紫外线波长365 nm;能量密度3 mW/cm2;照射时间40 min.生物力学测试指标:极限应力、8％应变条件下的应力和弹性模量.应用t检验对交联前后的生物力学指标进行统计分析.结果 8％应变时兔和人巩膜应力分别为(359±305)kPa和(1 079±646)kPa;极限应力分别为(3 830±2 870)kPa和(4450±1 120)kPa;弹性模量分别为(4 460±4090)kPa和(14 310±8 560)kPa.交联后兔巩膜在应力、极限应力和弹性模量上均有显著性提高(t=3.07、3.50、3.04,P＜0.05);而人巩膜交联前后的生物力学指标差异均无统计学意义.结论 人巩膜生物力学性能高于兔;胶原交联可显著增加兔巩膜生物力学性能,而在相同条件下人巩膜交联前后生物力学强度无改变.%Objective To compare the biomechanical properties of rabbit and human sclera before and after riboflavin/ultraviolet A (UVA) collagen crosslinking.Methods Experimental study.Eight rabbits and 8 human eyeballs were included.The eyes were bisected,one half was cross-linked with riboflavin/UVA (photosensitizer:0.1％ riboflavin drops for 15 minutes,UVA:3 mW/cm2,365 nm,and 40 minutes) and the other half served as control.Biomechanical properties testing consisted of ultimate stress,stress and Young's modulus at 8％ strain.Data were analyzed using t test.Results In untreated rabbit and human sclera,Young's modulus at 8％ strain was (4 460±4 090)kPa and (14310±8560)kPa,the stress was (359±305)kPa and (1 079±646)kPa,the ultimate stress was (3 830±2 870)kPa and (4 450±1 120)kPa.In rabbit sclera,the stress,ultimate stress and Young's modulus were significantly increased by riboflavin/UVA crosslinking (t=3.07,3.50,3.04,P＜0.05).The biomechanical properties of human sclera were not statistically affected by crosslinking.Conclusion Human sclera has a higher biomechanical stiffness than rabbit sclera.With the same irradiation dose,riboflavin/UVA crosslinking increases the biomechanical stiffness of rabbit sclera,but not human sclera.