眼外肌接触巩膜（眼球）的生物力学机制

The incidence of strabismus in China is higher than that of foreign countries. Clinically, modeling eye movement is helpful for the diagnosis and analysis of strabismus. However, the current models of eye movement have a certain limitation. The main reason is lack of investigations on the biomechanical behaviors of the tissues related to eye movement. In our opinion, the limitation of modeling eye movement may be overcome by understanding how extraocular muscles (EOMs) contact sclera (eyeball). This project will employ local indentation-detachment test (with a rigid probe of 1mm-diameter) to determine the in vivo- and in vitro- biomechanical properties and capillarity of EOMs contacting sclera, for they are the biological soft tissues with viscoelastic behavior. Additionally, the contact -detachment phenomenon of EOMs and sclera will be observed using an animal in vitro-experiment. To illustrate the biomechanical mechanism of EOMs contacting sclera, a mathematical model will be built with continuum mechanics and current theory of elastocapillarity. Performance of this project is helpful for further investigation of modeling eye movement.

我国斜视发病率高于国外平均水平，眼球运动建模有助于临床上对斜视的诊断和分析。但是，现有的眼球运动模型有一定的局限性，主要是因为缺乏对眼球运动相关的生物软组织力学行为的研究。我们认为研究眼外肌接触巩膜（眼球）的行为能进一步弥补眼球运动建模的局限性。本项目拟用自制直径1mm的刚性探针，行局部压痕（压入-分离）实验，分别测试生物软组织粘弹性材料眼外肌和巩膜的在体-/离体-生物力学性质和相互接触时的毛细管效应（capillarity）。在此基础上，用手术动物模型行在体实验观测眼外肌与巩膜的接触-分离现象，建立考虑现有的弹性-毛细管效应理论和连续介质力学的模型阐述眼外肌接触巩膜的生物力学机制，为进一步完善眼球运动建模的研究提供理论基础。

眼表组织的粘附行为对眼的生理活动及临床治疗有重要意义，比如眼球运动的过程因巩膜与眼外肌相互间的粘附作用而频繁发生的接触-分离行为，屈光手术后角膜的稳定性依赖于角膜创面间彼此的粘附作用。但是，目前却鲜见有关眼表组织粘附行为的文献报道。为此，本项目提出用压痕-分离实验测试眼表组织的粘附行为的思想。项目执行期间，除分析了角膜和巩膜与压痕行为有关的局部弹性行为外，着重分析了角膜组织粘附行为的尺寸效应，并改进了分析固体软材料粘附行为的传统的Johnson-Kendall-Roberts（JKR）理论，使改进后的JKR模型适用于分析角膜之类力学性质介于固体和膜的软组织。此外，利用传统的撕裂理论初步分析了眼外肌与巩膜间的粘附行为对眼球运动的调节作用。