A Modeling Approach for Investigating Opto-Mechanical Relationships in the Human Eye Lens

Wang, Kehao and Venetsanos, Demetrios T. and Hoshino, Masato and Uesugi, Kentaro and Yagi, Naoto and Pierscionek, Barbara K. (2020) A Modeling Approach for Investigating Opto-Mechanical Relationships in the Human Eye Lens. IEEE Transactions on Biomedical Engineering, 67 (4). pp. 999-1006. ISSN 1558-2531

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Official URL: https://doi.org/10.1109/TBME.2019.2927390

Abstract

Objective: The human visual system alters its focus by a shape change of the eye lens. The extent to which the lens can adjust ocular refractive power is dependent to a significant extent on its material properties. Yet, this fundamental link between the optics and mechanics of the lens has been relatively under-investigated. This study aims to investigate this opto-mechanical link within the eye lens to gain insight into the processes of shape alteration and their respective decline with age. Methods: Finite Element models based on biological lenses were developed for five ages: 16, 35, 40, 57, and 62 years by correlating in vivo measurements of the longitudinal modulus using Brillouin scattering with in vitro X-ray interferometric measurements of refractive index and taking into account various directions of zonular force. Results: A model with radial cortical Young's moduli provides the same amount of refractive power with less change in thickness than a model with uniform cortical Young's modulus with a uniform stress distribution and no discontinuities along the cortico-nuclear boundary. The direction of zonular angles can significantly influence curvature change regardless of the modulus distribution. Conclusions: The present paper proposes a modelling approach for the human lens, coupling optical and mechanical properties, which shows the effect of parameter choice on model response. Significance: This advanced modelling approach, considering the important interplay between optical and mechanical properties, has potential for use in design of accommodating implant lenses and for investigating non-biological causes of pathological processes in the lens (e.g., cataract).

Item Type: Journal Article
Keywords: Opto-mechanical modelling, finite element analysis, human eye lens, accommodation, radial cortical Young’s moduli, zonules
Faculty: Faculty of Health, Education, Medicine & Social Care
Depositing User: Lisa Blanshard
Date Deposited: 11 Feb 2021 09:33
Last Modified: 09 Sep 2021 18:53
URI: https://arro.anglia.ac.uk/id/eprint/706257

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