眼内房水流动的数值研究  

Numerical Study of Aqueous Humor Flow in Human Eyes

作　　者：蔡建程[1] 张宝允 曹月红[2] BRAZHENKO Volodymyr CAI Jiancheng;ZHANG Baoyun;CAO Yuehong;BRAZHENKO Volodymyr(College of Engineering,Zhejiang Normal University,Jinhua,Zhejiang 321004,P.R.China;Department of Ophthalmology,Jinhua People’s Hospital,Jinhua,Zhejiang 321000,P.R.China)

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

出　　处：《应用数学和力学》2021年第2期151-161,共11页Applied Mathematics and Mechanics

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：研究眼内房水流动有助于认识眼睛疾病(如青光眼)的发生机理.该文利用计算流体力学计算了人眼睫状体分泌的房水由后房流经5μm和30μm虹膜-晶体间隙进入前房,再经小梁网排出这一过程,分析了平视、仰视、俯视不同体位以及不考虑浮力因素的房水流场.结果表明不同情况的房水压力场类似,5μm虹膜-晶体间隙时后房眼压比前房约高30 Pa,而30μm时前后房压力基本相同,小梁网压力下降明显.前后房压差驱动房水从后房流经虹膜间隙到前房,而角膜与虹膜温差引起的自然对流为前房房水的主要流动.前房自然对流引起的压差变化在mPa量级,温度较高房水汇集区域压力稍高.平视时主要为前房虹膜侧房水上升、角膜侧下降的自然对流循环;仰视时瞳孔区房水沿前房中心轴上浮,然后沿角膜向周边下沉,从虹膜周边部位到瞳孔,形成轴对称的对流模式;对于俯视,流动模式与仰视正好相反,前房中心轴上房水从角膜运动到瞳孔处;不考虑浮力作用时,房水的平均速度比自然对流时小1~2个数量级.The study of intraocular aqueous humor(AH)flow is helpful to understand the mechanism of some eye diseases such as glaucoma.A numerical study of AH flow inside human eyes with the computational fluid dynamics(CFD)were carried out to address the following flow processes:AH secreted in the posterior chamber by the ciliary body entering the anterior chamber through the iris-lens gap of 5μm and 30μm respectively,and discharging through the trabecular meshwork(TM).Detailed flow fields in different eye orientations were analyzed.Results show that,in general the intraocular pressure distributions are similar in all cases;the pressure in the posterior chamber is around 30 Pa higher than that in the anterior chamber with the 5μm iris-lens gap,and they are almost equal with the 30μm iris-lens gap.The pressure drop in the TM is noticeable.The pressure difference between the anterior and posterior chambers drives AH from the posterior chamber to the anterior chamber,while the temperature difference between cornea and iris surfaces causes the natural convection,which is the dominant flow in the anterior chamber.The pressure difference due to natural convection is in the magnitude of millipascal,and the higher-pressure region forms where warmer AH gathers.For the vertical orientation,warmer fluid rises along the iris surface and then turns downwards as it encounters the higher resistance in the upper TM regions.The flow then descends along the corneal surface toward the lower TM.For the upward-facing position,AH entering the pupil rises along the center line of the anterior chamber,and moves down along the cornea surface leading to axisymmetric recirculation zones.For the downward-facing position,the circulation route is opposite to that of the upward-facing position.With no buoyancy,the averaged velocity will be 1 to 2 orders of magnitude smaller than that with buoyancy.

关 键 词：房水流动 虹膜-晶体间隙 眼压 自然对流 数值研究 

分 类 号：O368[理学—流体力学] Q66[理学—力学]