基于快速加卸载的单轴拉伸识别屈光术后兔角膜的生物力学特性  

Characterization of rabbit corneal biomechanical properties after corneal refractive surgery based on rapid loading-unloading uniaxial tensile test

作　　者：张迪 张海霞[1] 李林[1] ZHANG Di;ZHANG Haixia;LI Lin(School of Biomedical Engineering,Capital Medical University,Beijing Key Laboratory of Fundamental Research on Biomechanics in Clinical Application,Capital Medical University,Beijing 100069,P.R.China;School of Radiology,Shandong First Medical University&Shandong Academy of Medical Sciences,Taian,Shandong 271016,P.R.China)

机构地区：[1]首都医科大学生物医学工程学院、首都医科大学临床生物力学应用基础研究北京市重点实验室,北京100069 [2]山东第一医科大学、山东省医学科学院放射学院,山东泰安271016

出　　处：《生物医学工程学杂志》2024年第1期136-143,共8页Journal of Biomedical Engineering

基　　金：国家自然科学基金资助项目(32171304,31470914);山东第一医科大学科教融合资助项目(YS23-0000823);临床生物力学应用基础研究北京市重点实验室资助项目(2023KF01)。

摘　　要：为了认识行角膜切削手术后兔眼角膜生物力学特性随修复时间如何变化,本研究选取21只健康成年兔,左眼作为实验眼,右眼作为对照眼,进行对比实验。首先,对所有兔的左眼采用板层刀移除角膜前表面部分组织(原角膜厚度的30%~50%),作为模拟角膜屈光手术的动物模型。其次,将实验兔分别饲养1个月、3个月、6个月后处死,利用其体外角膜制作条状试样,进行加卸载速率平均约为0.16 mm/s的单轴拉伸实验;最后,利用黏—超弹性本构模型,对加卸载数据进行拟合。结果显示,模拟手术后1个月、3个月,实验眼与对照眼角膜的黏弹性参数差异具有统计学意义;术后3个月,实验眼角膜与对照眼角膜,在应变水平分别为0.02、0.05时,其切向模量差异具有统计学意义;术后6个月组的实验眼角膜与对照眼角膜,生物力学参数差异无统计学意义。上述结果表明,与对照眼相比,实验眼角膜生物力学特性随术后时间有所变化,术后3个月实验眼与对照眼之间角膜的切向模量的比值增大,随后减小;这为基于临床上获取的快速测试数据认识角膜屈光手术术后角膜生物力学特性奠定了前期基础。In order to understand how the biomechanical properties of rabbit cornea change over time after corneal ablation,21 healthy adult rabbits were used in this study,with the left eye as experimental side and the right eye as the control side.Firstly,a lamellar knife was used to remove a portion of the anterior corneal surface tissue(30%~50%of the original corneal thickness)from the left eye of each rabbit,as an animal model simulating corneal refractive surgery.Secondly,postoperative experimental rabbits were kept for one,three,or six months until being euthanized.Strip specimens were produced using their corneas in vitro to perform a uniaxial tensile test with an average loading-unloading rate of approximately 0.16 mm/s.Finally,the visco-hyperelastic material constitutive model was used to fit the data.The results showed that there was a significant difference in the viscoelastic parameters of the corneas between the experimental and the control eyes at the first and third postoperative months.There was a difference in tangential modulus between the experimental and the control eyes at strain levels of 0.02 and 0.05 at the third postoperative month.There was no significant difference in biomechanical parameters between the experimental and the control eyes at the sixth postoperative month.These results indicate that compared with the control eyes,the biomechanical properties of the experimental eyes vary over postoperative time.At the third postoperative month,the ratio of corneal tangential modulus between the experimental and the control eyes significantly increased,and then decreased.This work lays a preliminary foundation for understanding the biomechanical properties of the cornea after corneal refractive surgery based on rapid testing data obtained clinically.

关 键 词：角膜 角膜屈光手术 生物力学特性 单轴拉伸实验 黏—超弹性 

分 类 号：R779.6[医药卫生—眼科] R318.01[医药卫生—临床医学]