角膜塑形镜几何设计参数对角膜生物力学影响的有限元研究  

Influence of Orthokeratology Lens Geometric Design Parameters on Corneal Biomechanics:A Finite Element Study

作　　者：吴丽敏 赵改平[1] 张泽众 项华中[1] 陈齐欧 陈炽 WU Limin;ZHAO Gaiping;ZHANG Zezhong;XIANG Huazhong;CHEN Qiou;CHEN Chi(School of Health Science and Engineering,University of Shanghai for Science and Technology,Shanghai 200093,China;MicroPort Vision Power MedTech(Shanghai)Co.,Ltd.,Shanghai 201318,China)

机构地区：[1]上海理工大学健康科学与工程学院,上海200093 [2]微创视神医疗科技(上海)有限公司,上海201318

出　　处：《医用生物力学》2024年第4期742-749,共8页Journal of Medical Biomechanics

基　　金：国家自然科学基金项目(51735003);广东省微创手术器械制造技术重点实验室(MISIMT20224);上海市科委医学创新研究专项(21Y11911600)。

摘　　要：目的探究角膜塑形镜(OK镜)不同几何设计参数对角膜生物力学影响的差异,揭示OK镜影响角膜塑形机制。方法建立非球面OK镜和角巩膜耦合三维有限元模型,数值分析OK镜不同近视矫正度数对应几何设计参数改变对角膜前表面轮廓和曲率分布规律、角膜前表面和角膜基质层上表面von Mises应力(von Mises stress,VMS)和眼轴位移变化的影响。结果角膜前表面的应力集中出现在中周区和周边区,而基质层上表面的应力集中仅出现在中周区。OK镜基弧的矢高随着近视矫正度数增加而减小,矫正度数为-2.0、-3.0、-4.0、-5.0、-6.0 D时,角膜最大VMS比-1.0 D增加0.81%、1.86%、2.84%、3.81%和7.04%,角膜中央区的曲率比未戴镜时平均减少2.59、3.78、4.51、4.99、5.33、6.41 D。结论近视矫正度数增加使OK镜基弧的矢高减小,导致角膜中央曲率更加平坦。OK镜的基弧区对于近视矫正和控制起着十分重要的作用。Objective To investigate corneal biomechanical differences in different geometric design parameters of orthokeratology lenses(OK lenses)and to further reveal the corneal shaping mechanism of OK lenses.Methods A coupled finite element model of the aspheric OK lens corneosclera was established for various geometric design parameters of the OK lens,corresponding to different degrees of myopia correction.The distribution trends of the profile and curvature of the corneal anterior surface,as well as the von Mises stress(VMS)and eye axis displacement on both the corneal anterior surface and superior corneal stroma surface were analyzed numerically.Results The stress concentration of the corneal anterior surface was observed in the mid-peripheral and peripheral zones,whereas that of the superior corneal stroma surface appeared in the mid-peripheral zones.The sagittal height of the base curve of the OK lens decreased with increasing degree of myopia correction.At myopia correction degrees of-2.0,-3.0,-4.0,-5.0,and-6.0 D,the maximum corneal VMS increased by 0.81%,1.86%,2.84%,3.81%,and 7.04%,respectively,compared with that at-1.0 D;the curvature of the corneal central zone was reduced by an average of 2.59,3.78,4.51,4.99,5.33,and 6.41 D compared with that without OK lenses.Conclusions The sagittal height of the base curve of the OK lens decreased with increasing degree of myopia correction,resulting in a flatter central curvature of the cornea.The base curve of the OK lens plays a crucial role in both correction and control of myopia.

关 键 词：角膜生物力学 角膜塑形镜 近视矫正度数 角膜塑形 有限元分析 

分 类 号：R318.01[医药卫生—生物医学工程]