Automatized Patient-Specific Methodology for Numerical Determination of Biomechanical Corneal Response

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• 作者：M. Á. Ariza-Gracia ; J. Zurita ; D. P. Piñero ; B. Calvo…
• 刊名：Annals of Biomedical Engineering
• 出版年：2016
• 出版时间：May 2016
• 年：2016
• 卷：44
• 期：5
• 页码：1753-1772
• 全文大小：4,851 KB
• 刊物类别：Biomedical and Life Sciences
• 刊物主题：Biomedicine
  Biomedicine
  Biomedical Engineering
  Biophysics and Biomedical Physics
  Mechanics
  Biochemistry
  
• 出版者：Springer Netherlands
• ISSN：1573-9686
• 卷排序：44

文摘

This work presents a novel methodology for building a three-dimensional patient-specific eyeball model suitable for performing a fully automatic finite element (FE) analysis of the corneal biomechanics. The reconstruction algorithm fits and smooths the patient’s corneal surfaces obtained in clinic with corneal topographers and creates an FE mesh for the simulation. The patient’s corneal elevation and pachymetry data is kept where available, to account for all corneal geometric features (central corneal thickness–CCT and curvature). Subsequently, an iterative free-stress algorithm including a fiber’s pull-back is applied to incorporate the pre-stress field to the model. A convergence analysis of the mesh and a sensitivity analysis of the parameters involved in the numerical response is also addressed to determine the most influential features of the FE model. As a final step, the methodology is applied on the simulation of a general non-commercial non-contact tonometry diagnostic test over a large set of 130 patients—53 healthy, 63 keratoconic (KTC) and 14 post-LASIK surgery eyes. Results show the influence of the CCT, intraocular pressure (IOP) and fibers (87%) on the numerical corneal displacement \(({{U}}_{{Num}}),\) the good agreement of the \({{U}}_{{Num}}\) with clinical results, and the importance of considering the corneal pre-stress in the FE analysis. The potential and flexibility of the methodology can help improve understanding of the eye biomechanics, to help to plan surgeries, or to interpret the results of new diagnosis tools (i.e., non-contact tonometers).KeywordsFEM corneal modelPatient-specificSensitivity analysisNon-contact tonometry