Biomechanics and Modeling in Mechanobiology

, Volume 12, Issue 5, pp 941–963

Scleral anisotropy and its effects on the mechanical response of the optic nerve head

  • Baptiste Coudrillier
  • Craig Boote
  • Harry A. Quigley
  • Thao D. Nguyen
Original Paper

Abstract

This paper presents a computational modeling study of the effects of the collagen fiber structure on the mechanical response of the sclera and the adjacent optic nerve head (ONH). A specimen-specific inverse finite element method was developed to determine the material properties of two human sclera subjected to full-field inflation experiments. A distributed fiber model was applied to describe the anisotropic elastic behavior of the sclera. The model directly incorporated wide-angle X-ray scattering measurements of the anisotropic collagen structure. The converged solution of the inverse method was used in micromechanical studies of the mechanical anisotropy of the sclera at different scales. The effects of the scleral collagen fiber structure on the ONH deformation were evaluated by progressively filtering out local anisotropic features. It was found that the majority of the midposterior sclera could be described as isotropic without significantly affecting the mechanical response of the tissues of the ONH. In contrast, removing local anisotropic features in the peripapillary sclera produced significant changes in scleral canal expansion and lamina cribrosa deformation. Local variations in the collagen structure of the peripapillary sclera significantly influenced the mechanical response of the ONH.

Keywords

Sclera Optic nerve head  Inverse finite element method Wide-angle X-ray scattering Inflation experiment 

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Copyright information

© Springer-Verlag Berlin Heidelberg 2012

Authors and Affiliations

  • Baptiste Coudrillier
    • 1
  • Craig Boote
    • 2
  • Harry A. Quigley
    • 3
  • Thao D. Nguyen
    • 1
  1. 1.Department of Mechanical EngineeringJohns Hopkins UniversityBaltimoreUSA
  2. 2.Structural Biophysics Group, School of Optometry and Vision SciencesCardiff UniversityCardiffWales, UK
  3. 3.Glaucoma Center of Excellence, Wilmer Ophthalmological InstituteJohns Hopkins University School of MedicineBaltimoreUSA

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