Quantitative corneal elastography using high-frequency ultrasound

Thesis (Ph. D.)--University of Rochester. Department of Physics and Astronomy, 2018.Measurement of corneal biomechanical properties can aid in predicting corneal responses to diseases and surgeries. Different biomechanical characteristics of the cornea have been studied primarily through ex vivo destructive testing. However, destructive methods are not suitable for in vivo applications and do not preserve the natural environment of the cornea. These motivate development of nondestructive means to measure corneal biomechanical properties. Currently, there is no clinically available in vivo instrumentation that can provide spatially-resolved distribution of corneal biomechanical properties. In this dissertation, we demonstrate a high-resolution ultrasound elastography system using high-frequency ultrasound for ex vivo measurement of strain-dependent corneal wave speed. Corneal wave speed was found to be a linear function of IOP. We also observed depth-dependent variations of wave speed in the cornea, decreasing from anterior toward posterior. This depth dependence is more pronounced at higher IOP values. This work demonstrates the potential of high-frequency ultrasound elastography in the characterization of corneal biomechanical properties