Modelagem computacional da biomecânica da córnea humana

Abstract

The cornea is the main refractive structure of the human eye, and its optical function depends directly on its biomechanical integrity. Predicting the behavior of this tissue under loading is challenging due to its anisotropic and non-linear nature, governed by a

complex microstructure of collagen fibers. This work aims to implement the Holzapfel- Gasser-Ogden (HGO) hyperelastic constitutive model in the commercial software Simulia

Abaqus, overcoming native limitations through the development of user subroutines. The methodology consisted of programming a USDFLD subroutine in Fortran to define the fiber dispersion variable (κ) along the corneal geometry. The model was initially

validated by reproducing uniaxial tensile tests on stromal strips. Subsequently, a three- dimensional simulation of corneal inflation was performed. The results indicated that

the implementation allowed representing the tissue anisotropy and showed satisfactory agreement with experimental literature data, following the strain-stiffening behavior. It is concluded that the proposed computational approach is viable for corneal biomechanical analysis, constituting a promising tool for future clinical and engineering investigations.