The mechanical anisotropic properties of the cornea can be an important indicator for determining the onset and severity
of different diseases and can be used to assess the efficacy of various therapeutic interventions, such as cross-linking and
LASIK surgery. In this work, we introduce a noncontact method of assessing corneal mechanical anisotropy as a
function of intraocular pressure (IOP) using optical coherence elastography (OCE). A focused air-pulse induced low
amplitude (<10 μm) elastic waves in fresh porcine corneas in the whole eye-globe configuration in situ. A phase-stabilized
swept source optical coherence elastography (PhS-SSOCE) system imaged the elastic wave propagation at
stepped radial angles, and the OCE measurements were repeated as the IOP was cycled. The elastic wave velocity was
then quantified to determine the mechanical anisotropy and hysteresis of the cornea. The results show that the elastic
anisotropy at the corneal of the apex of the cornea becomes more pronounced at higher IOPs, and that there are distinct
radial angles of higher and lower stiffness. Due to the noncontact nature and small amplitude of the elastic wave, this
method may be useful for characterizing the elastic anisotropy of ocular and other tissues in vivo completely
noninvasively.
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