Capturing sclera anisotropy using direct collagen fiber models. Linking microstructure to macroscopic mechanical...

Area of Science:

• Biomechanical Engineering
• Ocular Biomechanics
• Computational Modeling

Background:

• Collagen fibers are critical for soft tissue mechanics.
• Conventional continuum models homogenize scleral fibers.
• Direct fiber modeling offers a more detailed approach.

Purpose of the Study:

• To capture specimen-specific 3D fiber architecture and anisotropic mechanics of sclera.
• To validate direct fiber modeling for complex loading conditions.
• To assess the method's ability to link microstructure to macroscale behavior.

Main Methods:

• Developed specimen-specific direct fiber models using microstructural data from polarized light microscopy.
• Tested sclera samples under equibiaxial and non-equibiaxial loadings.
• Employed inverse-fitting to determine fiber mechanical properties.

Main Results:

• Model fiber orientations closely matched histological data (adjusted R2 > 0.89).
• Direct fiber models accurately predicted both equibiaxial and non-equibiaxial mechanical behaviors.
• The model inherently accounted for tissue anisotropy.

Conclusions:

• Direct fiber modeling successfully captures specimen-specific scleral architecture and mechanics.
• This approach provides a powerful tool for understanding structure-function relationships in soft tissues.
• Direct fiber modeling is a promising method for simulating anisotropic tissue behavior.