Instituto de Microelectrónica de Barcelona, IMB-CNM (CSIC), Campus UAB, 08193 Bellaterra, Barcelona, Spain.
Med Eng Phys. 2010 Dec;32(10):1107-15. doi: 10.1016/j.medengphy.2010.07.016. Epub 2010 Sep 15.
The permeability of the corneal endothelial layer has an important role in the correct function of the cornea. Since ionic permeability has a fundamental impact on the passive electrical properties of living tissues, here it is hypothesized that impedance methods can be employed for assessing the permeability of the endothelial layer in a minimally invasive fashion. Precisely, the main objective of the present study is to develop and to analyze a minimally invasive method for assessing the electrical properties of the corneal endothelium, as a possible diagnostic tool for the evaluation of patients with endothelial dysfunction. A bidimensional model consisting of the main corneal layers and a four-electrode impedance measurement setup placed on the epithelium has been implemented and analyzed by means of the finite elements method (FEM). In order to obtain a robust indicator of the permeability of the endothelium layer, the effect of the endothelium electrical properties on the measured impedance has been studied together with reasonable variations of the other model layers. Simulation results show that the impedance measurements by means of external electrodes are indeed sufficiently sensitive to the changes in the electrical properties of the endothelial layer. It is concluded that the method presented here can be employed as non-invasive method for assessing endothelial layer function.
角膜内皮层的通透性对于角膜的正常功能具有重要作用。由于离子通透性对生物组织的被动电学性质具有根本影响，因此在这里假设可以采用阻抗方法以微创的方式评估内皮层的通透性。具体而言，本研究的主要目的是开发和分析一种用于评估角膜内皮电特性的微创方法，作为评估内皮功能障碍患者的一种可能的诊断工具。采用二维模型，该模型由主要的角膜层和放置在上皮上的四电极阻抗测量装置组成，并通过有限元方法（FEM）进行了实现和分析。为了获得内皮层通透性的稳健指标，研究了与其他模型层的合理变化一起，内皮电特性对测量阻抗的影响。仿真结果表明，通过外部电极进行的阻抗测量确实对内皮层电特性的变化非常敏感。得出的结论是，本文提出的方法可作为评估内皮层功能的非侵入性方法。
