Quantitative assessment of corneal viscoelasticity using optical coherence elastography and a modified Rayleigh-Lamb equation

We demonstrate the use of a modified Rayleigh-Lamb frequency equation in conjunction with noncontact optical coherence elastography to quantify the viscoelastic properties of the cornea. Phase velocities of air-pulse-induced elastic waves were extracted by spectral analysis and used for calculating the Young's moduli of the samples using the Rayleigh-Lamb frequency equation (RLFE). Validation experiments were performed on 2% agar phantoms (n = 3) and then applied to porcine corneas (n = 3) in situ. The Young's moduli of the porcine corneas were estimated to be ∼60 kPa with a shear viscosity ∼0.33 Pa · s. The results demonstrate that the RLFE is a promising method for noninvasive quantification of the corneal biomechanical properties and may potentially be useful for clinical ophthalmological applications.