摘要
目的探索圆锥角膜拟锥体的中心位置和力学性质对角膜动力学响应参数的影响。方法基于90例顿挫期圆锥角膜(forme fruste keratoconus,FFKC)患者三维眼前节分析诊断系统给出的角膜形态数据,用锥体自动获取方法确定其拟锥体参数。依据所得拟锥体中心位置选取两组(水平组21例,下方组20例),分析组间角膜动力学响应(dynamics corneal response,DCR)参数的差异。基于健康眼球几何数据构建具有3种不同锥体位置的圆锥角膜有限元模型,改变锥体区域的力学参数,计算给出在空气脉冲作用下DCR参数的模拟结果,用于研究角膜锥体区域的位置和力学参数同DCR参数的关系。结果FFKC的拟锥体中心位置不同,在DCR参数中,最大压陷曲率半径(radius)、最大凹陷曲率(maximum inverse radius,MIR)和积分半径(integration radius,IR)存在统计学差异。当FFKC拟锥体中心位于角膜旁中心区域时,只有与拟锥体区域呈中心对称的区域的角膜厚度存在统计学差异。有限元模拟结果显示,锥体位于角膜正下方较位于水平侧的角膜顶点最大位移改变量大;当锥体位于角膜中心和正下方时,MIR变小,IR变大,且随着锥体区域力学参数的衰减,MIR和IR的变化量随之增大;当锥体区域位于水平侧时,MIR和IR的变化不大。结论FFKC拟锥体的中心位置和力学参数的衰减程度均对DCR参数(MIR和IR等)有显著影响。
Objective The study aims to explore the influence of the position and mechanical properties of the cone of keratoconus on the dynamic corneal response(DCR) parameters.Methods Ninety patients(90 eyes) with forme fruste keratoconus(FFKC) were included.Based on the morphological data of FFKC,the cone parameters were determined by the cone automatic acquisition method.According to the cone center,21 cases in horizontal group and 20 cases in underside group were selected to analyze the difference of dynamic corneal response parameters.A finite element model of keratoconus with three different cone positions was constructed based on the geometric data of healthy eyeballs.By changing the mechanical parameters of the cone region,the simulation results of corneal dynamic response parameters under air pulse were calculated to study the relationship of the position and mechanical parameters of the corneal cone region with the DCR parameters.Results There were statistical differences among the corneal radius at time of corneal concavity(radius),maximum inverse radius(MIR) and integrated radius(IR) due to the different positions of the cone center in forme fruste keratoconus.When the cone center was located in the paracorneal central area,only the corneal thickness of the area symmetrical to the cone center was statistically different.The finite element simulation results showed that the maximum displacement of the corneal vertex that cone region located below the cornea was larger than located on the horizontal line.When the cone was located on the center and the vertical line,MIR became smaller and IR became larger,and the changes of MIR and IR increased with the decrease of mechanical parameters in the cone region.When the cone region was located on the horizontal line,MIR and IR changed little.Conclusions The position and mechanical properties of cone have significant effects on DCR parameters(MIR,IR,etc.) of FFKC.
作者
王维
张慧
田磊
李林
张海霞
WANG Wei;ZHANG Hui;TIAN Lei;LI Lin;ZHANG Haixia(School of Biomedical Engineering,Capital Medical University,Beijing 100069;Beijing Tongren Hospital,Capital Medical University,Beijing 100730;Beijing Key Laboratory of Fundamental Research on Biomechanics in Clinical Application,Beijing 100069)
出处
《北京生物医学工程》
2023年第6期566-573,共8页
Beijing Biomedical Engineering
基金
国家自然科学基金(32171304)资助。
关键词
顿挫期圆锥角膜
生物力学
有限元模拟
最大压陷曲率半径
积分半径
forme fruste keratoconus
biomechanics
finite element simulation
maximum indentation radius of curvature
integrated radius
