Institute for Surgical Technology and Biomechanics, University of Bern, Switzerland.
J Biomech. 2010 Mar 22;43(5):836-42. doi: 10.1016/j.jbiomech.2009.11.021. Epub 2009 Dec 14.
The optical characteristics of the human cornea depends on the mechanical balance between the intra-ocular pressure and intrinsic tissue stiffness. A wide range of ophthalmic surgical procedures alter corneal biomechanics to induce local or global curvature changes for the correction of visual acuity. Due to the large number of surgical interventions performed every day, a deeper understanding of corneal biomechanics is needed to improve the safety of these procedures and medical devices. The aim of this study is to propose a biomechanical model of the human cornea, based on stromal microstructure. The constitutive mechanical law includes collagen fiber distribution based on X-ray scattering analysis, collagen cross-linking, and fiber uncrimping. Our results showed that the proposed model reproduced inflation and extensiometry experimental data [Elsheikh et al., Curr. Eye Res., 2007; Elsheikh et al., Exp. Eye Res., 2008] successfully. The mechanical properties obtained for different age groups demonstrated an increase in collagen cross-linking for older specimens. In future work such a model could be used to simulate non-symmetric interventions, and provide better surgical planning.
角膜的光学特性取决于眼内压和固有组织硬度之间的机械平衡。广泛的眼科手术改变了角膜生物力学，以诱导局部或全局曲率变化，从而矫正视力。由于每天进行大量的手术干预，因此需要更深入地了解角膜生物力学，以提高这些手术和医疗器械的安全性。本研究旨在基于基质微观结构提出一种人类角膜的生物力学模型。本构力学定律包括基于 X 射线散射分析的胶原纤维分布、胶原交联和纤维解捻。我们的研究结果表明，所提出的模型成功地再现了膨胀和拉伸实验数据[Elsheikh 等人，Curr. Eye Res.，2007 年；Elsheikh 等人，Exp. Eye Res.，2008 年]。不同年龄组获得的机械性能表明，老年标本的胶原交联增加。在未来的工作中，这种模型可以用于模拟非对称干预，并提供更好的手术规划。
