Aragόn Institute of Engineering Research (i3A), University of Zaragoza, Zaragoza, Spain.
Bioengineering, Biomaterials and Nanomedicine Networking Biomedical Research Centre (CIBER-BBN), Zaragoza, Spain.
Ophthalmic Physiol Opt. 2021 Nov;41(6):1241-1253. doi: 10.1111/opo.12876. Epub 2021 Aug 31.
To reproduce human in vivo accommodation numerically. For that purpose, a finite element model specific for a 29-year-old subject was designed. Once the proposed numerical model was validated, the decrease in accommodative amplitude with age was simulated according to data available in the literature.
In contrast with previous studies, the non-accommodated eye condition was the reference configuration. Consequently, two aspects were specifically highlighted: contraction of the ciliary muscle, which was simulated by a continuum electro-mechanical model and incorporation of initial lens capsule stresses, which allowed the lens to become accommodated after releasing the resting zonular tension.
The morphological changes and contraction of the ciliary muscle were calibrated accurately according to the experimental data from the literature. All dynamic optical and biometric lens measurements validated the model. With the proposed numerical model, presbyopia was successfully simulated.
The most widespread theory of accommodation, proposed by Helmholtz, was simulated accurately. Assuming the same initial stresses in the lens capsule over time, stiffening of the lens nucleus is the main cause of presbyopia.
数值再现人体的活体调节。为此，设计了一个针对 29 岁受试者的特定有限元模型。在验证了所提出的数值模型后，根据文献中的可用数据模拟了调节幅度随年龄的下降。
与以前的研究不同，未调节的眼睛状态是参考配置。因此，特别强调了两个方面：睫状肌的收缩，通过连续体机电模型进行模拟，以及初始晶状体囊张力的结合，这允许在释放静止的悬韧带张力后使晶状体适应。
根据文献中的实验数据，对睫状肌的形态变化和收缩进行了精确校准。所有动态光学和生物测量晶状体测量都验证了该模型。通过提出的数值模型，成功模拟了远视。
准确模拟了最广泛的调节理论，由亥姆霍兹提出。假设晶状体囊中的初始应力随时间保持不变，晶状体核变硬是远视的主要原因。
