Key Laboratory for Biomechanics and Mechanobiology of Ministry for Education, Beijing Advanced Innovation Center for Biomedical Engineering, Beihang University, Beijing, China; School of Engineering Medicine, Beihang University, Beijing, China.
Key Laboratory for Biomechanics and Mechanobiology of Ministry for Education, Beijing Advanced Innovation Center for Biomedical Engineering, Beihang University, Beijing, China; School of Biological Science and Medical Engineering, Beihang University, Beijing, China.
Comput Biol Med. 2023 Jun;160:106972. doi: 10.1016/j.compbiomed.2023.106972. Epub 2023 Apr 26.
Current treatment of cataract widely used in clinics is by removal of the opacified content from the lens capsule which is followed by insertion of an artificial intraocular lens (IOL). The IOL needs to remain stabilized in the capsular bag for the eye to achieve desired optical quality. The present study aims to investigate how different design parameters of the IOL can influence the axial and rotational stabilities of IOLs using Finite Element Analysis.
Eight designs of IOL with variations in types of optics surface, types of haptics and haptic angulation were constructed using parameters obtained from an online IOL databank (IOLs.eu). Each IOL was subjected to compressional simulations both by two clamps and by a collapsed natural lens capsule with an anterior rhexis. Comparisons were made between the two scenarios on axial displacement, rotation, and distribution of stresses.
The clamps compression method set out by ISO does not always produce the same outcome as the in-the-bag analysis. The open-loop IOLs show better axial stability while the closed-loop IOLs show better rotational stability when compressed by two clamps. Simulations of IOL in the capsular bag only demonstrate better rotational stability for closed-loop designs.
The rotational stability of an IOL is largely dependent on its haptic design whilst the axial stability is affected by the appearance of the rhexis to the anterior capsule which has a major influence on designs with a haptic angulation.
目前临床上广泛应用的白内障治疗方法是通过移除晶状体囊内的混浊内容物，然后植入人工晶状体（IOL）。IOL 需要稳定在囊袋内，以确保眼睛获得理想的光学质量。本研究旨在通过有限元分析研究 IOL 的不同设计参数如何影响 IOL 的轴向和旋转稳定性。
使用在线 IOL 数据库（IOLs.eu）中的参数构建了 8 种不同光学面、襻类型和襻角度的 IOL 设计。对每个 IOL 进行了两种夹钳压缩模拟和一个前房切开的塌陷自然晶状体囊压缩模拟。比较了两种情况下的轴向位移、旋转和应力分布。
ISO 规定的夹钳压缩方法并不总是产生与囊内分析相同的结果。在夹钳压缩下，开环 IOL 表现出更好的轴向稳定性，而闭环 IOL 表现出更好的旋转稳定性。仅在囊袋内模拟 IOL 时，闭环设计表现出更好的旋转稳定性。
IOL 的旋转稳定性主要取决于其襻设计，而轴向稳定性则受前囊切口对其的影响，这对具有襻角度的设计有重大影响。
