后房压力变化对虹膜变形的流固耦合有限元分析  

Finite Element Analysis of Iris Deformation under Intraocular Pressure through Fluid-Structure Coupling

作　　者：曹月红[1] 蔡建程[2] 陈雁翎 Brazhenko Volodymyr Mochalin Ievgen Cao Yuehong;Cai Jiancheng;Chen Yanling;Brazhenko Volodymyr;Mochalin Ievgen(Department of Ophthalmology,Jinhua People's Hospital,Jinhua 321000,China;College of Engineering,Zhejiang Normal University,Jinhua 321004,China)

机构地区：[1]金华市人民医院眼科,321000 [2]浙江师范大学工学院,金华321004

出　　处：《中华眼视光学与视觉科学杂志》2021年第6期401-408,共8页Chinese Journal Of Optometry Ophthalmology And Visual Science

基　　金：国家自然科学基金(51976201);金华市科技局重点项目(2019-3-016)。

摘　　要：目的:建立房水流动及虹膜变形的数学模型,定量分析因瞳孔阻滞造成前后房压差所引发的闭角型青光眼发病机制。方法:数值模拟研究。研究正常虹膜形状(虹膜-晶状体间隙为30μm)和瞳孔几乎后粘连(虹膜-晶状体间隙为5μm、2μm)下的房水流动及虹膜变形,利用计算流体动力学数值求解房水流动,并基于单向流固耦合技术进行虹膜在流场作用力下变形的有限元分析。结果:30μm的正常虹膜-晶状体间隙前后房的压力几乎相等;对于5μm和2μm的虹膜-晶状体间隙,后房比前房压力分别高31 Pa和815 Pa。利用乘幂函数对前后房压差与虹膜-晶状体间隙之间的关系进行拟合,发现当该间隙小于3μm后,前后房压差将异速增加形成显著虹膜膨隆,导致虹膜表面与角膜接触,引发房角关闭。结论:从生物力学的角度分析虹膜膨隆与房水流动的相互作用特征,能进一步定量揭示原发性闭角型青光眼瞳孔阻滞发病机制。Objective:To quantitatively analyze the pathogenesis of angle-closure glaucoma caused by an anterior and posterior chamber pressure difference due to pupil block using a mathematical model of aqueous humor flow and iris deformation.Methods:This was a numerical simulation research study.The aqueous humor flows with a normal iris shape(iris-lens gap of 30μm),and borderline synechia iris configurations(iris-lens gap of 5μm and 2μm).The respective iris deformations were studied.Based on the mathematical models of aqueous humor flow and iris deformation,the aqueous humor flows are solved by computational fluid mechanics,and through a one-way fluid-structure coupling technique,the deformations of the iris under the flow field pressures were calculated by finite element analysis.Results:For the normal iris-lens gap(30μm),the pressure of the anterior and posterior chamber is almost equal;for an iris-lens gap distance of 5μm and 2μm,the pressure differences between the posterior and anterior chamber was 31 Pa and 815 Pa,respectively.The relationship between the anterior and posterior chamber pressure difference and the iris-lens gap was obtained by nonlinear curve fit using the allometric function.It was found that when the iris lens gap was less than 5μm,the anterior and posterior chamber pressure difference increased dramatically.When the iris-lens gap was less than 3μm,severe iris bombécan occur so that the iris comes in contact with the cornea,causing angle closure glaucoma.Conclusions:Numerical analysis of the interaction between iris and aqueous humor from biomechanics can be helpful to quantitatively reveal the pathogenesis of pupil block in primary angle-closure glaucoma.

关 键 词：房水流动 虹膜变形 青光眼 流固耦合 数值研究 

分 类 号：R775[医药卫生—眼科]