Grytz, R: Computational Modeling and Remodeling of Human Eye

This thesis is concerned with the biomechanieal modeling of human eye tissues within a multi-scale framework considering the micro-, rneso-, and macro-structure in the context of constitutive formulation, computational modeling and remodeling. Consideration of the heterogeneous tissue substructures opens promising perspectives for more realistie biomechanieal modeling and computational simulations of the human eye in physiological and pathophysiologicaJ conditions. The biomechanical properties of eye tissues are derived from the single crimped fibril at the micro-scale via the collagen network of distributed fibrils at the meso-scale to the incompressible and anisotropie soft tissue at the macro-scale. Tissue adaptation and the mechanical condition within biological tissues are complex and mutually dependent phenomena. In this work, a computational model is presented to investigate the interaction between collagen fibril architecture and mechanicalloading conditions in eye tissues. Biomechanieally induced remodeling of the collagen network is considered at the meso-scale by allowing for a continuous re-orientation of collagen fibrils. To gain further insight into the complex multi-scale phenomena related to gJaucomatous optic neuropathy biomechanical computations of the lamina cribrosa at the meso- and macro-Ievel are performed. For multi-scale analyses of human eye shells the computational homogenization scheme is generalized to a consistent formulation of meso-macro transitions in curvilinear coordinates. The presented numerical results are in very good agreement with experimental observations at different length scaJes representing a novel, biomechanical paradigm for understanding the cause of glaucomatous optie neuropathy.