  A stable shape for corneas experiencing refractive surgery has to be
sustained so as to elude post-refractive surgery de-compensation. This
de-compensation leads to visual complications and unsatisfactory procedure
recovery. Variation in corneal lamellae and collagen fibres is induced by
recent LASER refractive surgical procedures utilizing LASER ablation and
disruption techniques. Conserving a steady response of central apex flattening
and peripheral steepening in an elastic cornea pre- and post- procedure is the
ultimate purpose of successful refractive surgery. Early diagnosis of ectatic
corneal disorders and better understanding of corneal pathogenesis is achieved
by assessment of corneal biomechanical properties. The ultimate objective of
this research is to estimate the biomechanical properties for both normal and
pathogenic corneal tissue pre- and post-operative refractive surgery. This
achieved using ultrasonic acoustic radiation force impulse as a non-invasive
method accounting for its high localization. Induced displacement tracking
methods will be utilized for assessment of soft tissue biomechanical properties
related to the investigated soft tissue. Ultrasound probe simulations will be
carried out to optimize the probe design. FEM simulations will take place to
precisely estimate in-situ corneal tissue biomechanics. In this research,
corneal biomechanical properties are studied and estimated using acoustic
radiation force impulse. This is achieved either by estimating the focal peak
axial deformation value or by estimating the shear wave speed for the resulting
propagating deformation wave.
