Nearly-incompressible transverse isotropy in the cornea: comparing mechanical tests with acoustic micro-tapping based optical coherence elastography

Accurate estimates of corneal mechanical properties may improve diagnosis and treatment of many ophthalmic conditions. Recently, we introduced a nearly incompressible transversely isotropic (NITI) model based on two independent shear moduli determining tensile and out-of-plane shear behavior. Here, we directly compare acoustic micro-tapping OCE (AμT-OCE) modulus estimates with those obtained from mechanical testing on ex-vivo porcine corneas. Both OCE and mechanical testing show tensile behavior governed by a Young’s modulus on the order of MPa and out-of-plane shear behavior by a modulus on the order of tens of kPa, suggesting strong anisotropy in the cornea.