Measuring and Modeling Elastography of Human Cornea Using Scanning Laser Doppler Vibrometry

Our interest is in noninvasively mapping the viscoelastic properties of the human cornea with the aid of a Scanning Laser Doppler Vibrometer (SLDV). Mechanical properties of the cornea can be used to predict early onset of diseases, such as glaucoma and keratoconus. By applying mechanical vibration near the cornea and measuring the dynamic wave propagation across the cornea, an elastographic map can be reconstructed. To effectively reconstruct the data, an appropriate analytical solution is needed to interpret the measured motion; in the present article, we review initial measurements and modeling of phantom cornea models. Several viscoelastic plate phantoms were constructed using silicone gels to simulate corneal structures. Comprehensive frequency sweeps were performed on these phantoms. The material can be represented using a fractional order model of viscoelasticity. Similar experiments have been completed on ex-vivo human cornea from donor eyes. The design shows proof of concept and is now being modified to a more applicable manner for in vivo experiments.