Functional effects of the spatial-varying lens mechanical properties in accommodation.
| Autor: | Schumacher J; Fischell Department of Bioengineering, University of Maryland, College Park, United States of America., Lopez RR; Fischell Department of Bioengineering, University of Maryland, College Park, United States of America., Larin K; Department of Biomedical Engineering, University of Houston, Houston, TX, United States of America., Manns F; Department of Biomedical Engineering, University of Miami, Coral Gables, FL, United States of America.; Ophthalmic Biophysics Center, Bascom Palmer Eye Institute, University of Miami Miller School of Medicine, Miami, FL, United States of America., Scarcelli G; Fischell Department of Bioengineering, University of Maryland, College Park, United States of America. |
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| Jazyk: | angličtina |
| Zdroj: | JPhys photonics [JPhys Photonics] 2024 Jul 01; Vol. 6 (3), pp. 035021. Date of Electronic Publication: 2024 Jul 02. |
| DOI: | 10.1088/2515-7647/ad3e55 |
| Abstrakt: | Lens biomechanical properties are critical for our eyes to accommodate. While it is well understood that lens mechanical properties change with age, different experimental techniques have been used over the years, with varying results on how the lens modulus changes. In this study, we developed a spatial-varying elasticity model to characterize the overall elastic modulus of the lens and establish its effect on accommodation. First, to validate the model, ex vivo porcine lenses underwent compression testing using biopsy punches of different diameters to change the percentage of nucleus within samples. Importantly, we found that, indeed, changing nucleus/cortex spatial ratio produces dramatic (∼7-fold) increase in overall sample modulus. Comparing the model with human lens spatial ratios, we demonstrate how changing spatial mechanics are more influential than peak modulus changes on overall elastic modulus. Next, in vivo clinical measurements of the spatial-varying lens modulus were used to generate a simplified mechanical-optical model of accommodation. We defined an ellipsoid lens with patient-derived modulus and geometry measurements, and a statics simulation and ray tracing analysis were performed through the deformed and undeformed lens. The resulting accommodation estimates agree with general accommodation expectations. (© 2024 The Author(s). Published by IOP Publishing Ltd.) |
| Databáze: | MEDLINE |
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