Corneal stiffness mapping that accounts for anisotropic properties of corneal tissue.

Abstract

This study introduces Stress-Strain Index (ASSI) maps that quantify and visualize corneal stiffness while accounting for anisotropy driven by collagen fibril orientation. Our earlier efforts to produce SSI maps assume isotropy and overlook directional stiffness variations critical to accurate modelling and diagnosis. By integrating fibril distribution data with finite element modelling, ASSI maps were developed for both healthy and keratoconic corneas. Clinical case studies demonstrated the maps' ability to capture age-related changes, surgical impacts, and disease progression. ASSI maps enhance understanding of corneal biomechanics and provide a foundation for more precise, personalized interventions in ophthalmology. This innovation may support improved diagnostic sensitivity, optimized treatment planning, and more equitable care through accessible, in-vivo biomechanical mapping technologies. STATEMENT OF SIGNIFICANCE: •This study introduces a stiffness mapping technique that accounts for the anisotropic properties of corneal tissue and directly incorporates the influence of collagen fibril distribution on biomechanical behavior. •By integrating numerical modeling, microstructural characterization, and clinical data, the proposed method enables estimation of biomechanical changes following corneal surgery, and supports monitoring of keratoconus progression. •The technique offers a versatile platform for interdisciplinary research at the intersection of biomechanics and clinical ophthalmology, highlighting the role of engineering in advancing personalized medicine.