  Purpose: To evaluate changes in the anisotropic elastic properties of ex vivo
human cornea treated with UV cross-linking (CXL) using non-contact acoustic
micro-tapping Optical Coherence Elastography (AuT-OCE) Design: AuT performed on
normal and CXL ex vivo human donor cornea Methods: Elastic properties of normal
and UV CXL treated human corneas were quantified using non-contact acoustic
micro-tapping Optical Coherence Elastography (AuT-OCE) Main Outcome Measures:
Corneal elastic moduli (in-plane Young's, E, and out-of-plane shear, G) can be
evaluated in both normal and CXL treated tissues, as well as during the CXL
procedure using non-contact AuT-OCE. Results: CXL induced a significant
increase in both the tensile and shear moduli in human cornea. The mean in the
paired study (pre- and post-, n=7) of the in-plane Young's modulus, E=3u,
increased from 19 MPa to 43 MPa while the out-of-plane shear modulus, G,
increased from 188 kPa to 673 kPa. Mechanical tests in a subgroup support
CXL-induced cornea moduli changes and generally agree with AuT-OCE.
Conclusions: The human cornea is a highly anisotropic material where in-plane
mechanical properties are very different from those out-of-plane. Non-contact
AuT-OCE can measure changes in the anisotropic elastic properties in human
cornea as a result of UV-CXL.
