基于虹膜膨隆过程的应力-应变关系的定量分析

Quantitative analysis of stress-strain relationship based on iris bombe

目的研究虹膜膨隆情况下虹膜变形与眼压之间的变化关系。方法针对目前虹膜膨隆过程中描述其变形与前后房压差之间定量关系不清楚的情况,采用理论建模的方法并且根据虹膜膨隆典型形态,简化结构特征;依据力学原理,建立了虹膜应变与前后房房水压差之间的函数关系。结果将虹膜膨隆简化为平面应变问题,虹膜的杨氏模量E不仅与虹膜半径R有关,更和应变系数K成正比。结论给出了一种计算虹膜膨隆应变的简单方法,可以直接根据超声生物显微镜扫描结果计算虹膜组织的力学特性,为临床医生选择适时手术时机,防止闭角型青光眼患者失明提供重要的理论依据。

Objective To investigate the relationship between iris bombe and intraocular pressure.Methods In view of the fact that the quantitative relationship between the iris deformation and the pressure difference between the anterior and posterior chambers was unknown during the current iris bombe process,the structural features were simplified based on the typical morphology of iris bombe.By means of the mechanics principle,the functional relationship between iris strain and aqueous humor pressure difference was established aiming to deal with the unclear quantitative relationship between the iris bombe and the aqueous humor pressure in the process of iris bombe.Results The iris bombe was simplified to the plane strain problem,and the Young’s modulus E of the iris was not only related to the iris radius R,but also proportional to the strain coefficient.Conclusion A simple method of calculating iris bombe strain is given.Therefore,the mechanical properties of iris tissue can be calculated directly from the results of ultrasound biomicroscopy.