Fibrous finite element modeling of the optic nerve head region

Authors

Mohammad R. Islam, The University of Texas Rio Grande Valley
Fengting Ji
Manik Bansal
Yi Hua
Ian A. Sigal

Document Type

Article

Publication Date

2-2024

Abstract

The optic nerve head (ONH) region at the posterior pole of the eye is supported by a fibrous structure of collagen fiber bundles. Discerning how the fibrous structure determines the region biomechanics is crucial to understand normal physiology, and the roles of biomechanics on vision loss. The fiber bundles within the ONH structure exhibit complex three-dimensional (3D) organization and continuity across the various tissue components. Computational models of the ONH, however, usually represent collagen fibers in a homogenized fashion without accounting for their continuity across tissues, fibers interacting with each other and other fiber-specific effects in a fibrous structure. We present a fibrous finite element (FFE) model of the ONH that incorporates discrete collagen fiber bundles and their histology-based 3D organization to study ONH biomechanics as a fibrous structure. The FFE model was constructed using polarized light microscopy data of porcine ONH cryosections, representing individual fiber bundles in the sclera, dura and pia maters with beam elements and canal tissues as continuum structures. The FFE model mimics the histological in-plane orientation and width distributions of collagen bundles as well as their continuity across different tissues. Modeling the fiber bundles as linear materials, the FFE model predicts the nonlinear ONH response observed in an inflation experiment from the literature. The model also captures important microstructural mechanisms including fiber interactions and long-range strain transmission among bundles that have not been considered before. The FFE model presented here advances our understanding of the role of fibrous collagen structure in the ONH biomechanics.

Comments

Original published version available at https://doi.org/10.1016/j.actbio.2023.12.034

Recommended Citation

Islam, Mohammad R., Fengting Ji, Manik Bansal, Yi Hua, and Ian A. Sigal. "Fibrous finite element modeling of the optic nerve head region." Acta Biomaterialia 175 (2024): 123-137. https://doi.org/10.1016/j.actbio.2023.12.034

Creative Commons License

This work is licensed under a Creative Commons Attribution-NonCommercial-No Derivative Works 4.0 International License.

Publication Title

Acta Biomaterialia

DOI

10.1016/j.actbio.2023.12.034