Quantitative Measurement of Viscoelastic Properties of Soft Membranes Subjected to Finite Deformations Based on Optical Coherence Elastography

Glaucoma is a leading cause of irreversible blindness that affects over 60 million people worldwide. Glaucomatous eyes are associated with risk factors such as elevated intraocular pressure (IOP) and low corneal hysteresis. Reliable non-invasive measurement of IOP remains a formidable challenge that limits the accurate diagnosis of glaucoma and associated intervention therapies. This work investigates the propagation of shear-dominated elastic waves in hydrostatically inflated corneal tissue phantoms based on the optical coherence elastography (OCE) technique. Unlike previous approaches reported in the literature, we analyze the dispersion relation of guided elastic waves in the phantoms by accounting for both small amplitude viscoelastic wave propagation and finite static deformations. The analytical approach we adopted will enable the determination of the storage and loss shear moduli dependence on finite strains in the cornea that results from hydrostatic pressures. This work provides a modeling and experimental framework for accurately characterizing viscoelastic properties and the IOP of corneal tissues.