Sródka Wiesław
Deformable Body Mechanics Faculty Unit, Wrocław University of Technology, Poland.
Acta Bioeng Biomech. 2011;13(3):77-85.
The values of the biomechanical human eyeball model parameters reported in the literature are still being disputed. The primary motivation behind this work was to predict the material parameters of the cornea through numerical simulations and to assess the applicability of the ubiquitously accepted law of applanation tonometry - the Imbert-Fick equation.
Numerical simulations of a few states of eyeball loading were run to determine the stroma material parameters. In the computations, the elasticity moduli of the material were related to the stress sign, instead of the orientation in space.
Stroma elasticity secant modulus E was predicted to be close to 0.3 MPa. The numerically simulated applanation tonometer readings for the cornea with the calibration dimensions were found to be lower by 11 mmHg then IOP = 48 mmHg.
This discrepancy is the result of a strictly mechanical phenomenon taking place in the tensioned and simultaneously flattened corneal shell and is not related to the tonometer measuring accuracy. The observed deviation has not been amenable to any GAT corrections, contradicting the Imbert-Fick law. This means a new approach to the calculation of corrections for GAT readings is needed.
文献中报道的人体眼球生物力学模型参数值仍存在争议。这项工作的主要动机是通过数值模拟预测角膜的材料参数，并评估普遍接受的压平眼压测量定律——伊姆伯特 - 菲克方程的适用性。
进行了几种眼球加载状态的数值模拟，以确定基质材料参数。在计算中，材料的弹性模量与应力符号相关，而非空间方向。
预测基质弹性割线模量E接近0.3兆帕。发现校准尺寸的角膜的数值模拟压平眼压计读数比眼压 = 48毫米汞柱时低11毫米汞柱。
这种差异是在张紧且同时变平的角膜壳中发生的严格力学现象的结果，与眼压计测量精度无关。观察到的偏差无法通过任何Goldmann压平眼压计（GAT）校正来解决，这与伊姆伯特 - 菲克定律相矛盾。这意味着需要一种新的方法来计算GAT读数的校正值。
