The goal of this research is to develop high-frequency three-dimensional (3D) ultrasound elasticity imaging which can detect the onset of keratoconus, monitor progression of this disease, and for late stage treatment aid corneal transplant surgery. High-frequency ultrasound elasticity imaging has mainly been used with two- dimensional (2D) motion tracking of tissue deformation. Unfortunately 2D elasticity imaging is severely restricted to well controlled tissue deformation in order to prevent artifacts caused by out-of-plane motion (motion perpendicular to the imaging plane). These restrictions prevent imaging of the full cornea and so limit the usefulness of 2D elasticity imaging for examining keratoconus. We can mitigate out-of-plane motion artifacts by developing high-frequency 3D motion tracking. To do this we will modify high-frequency ultrasound confocal imaging to be used for 3D imaging. We will adapt algorithms used for low-frequency 3D speckle tracking in breast tissue to high-frequency imaging of corneal tissue. Finally we will test these methods on cadaver pig eye globes. For some of these, stiffness regions in the cornea will be modified with chemicals like formalin and collagenase to simulate abnormal tissue. These techniques, developed for examining keratoconus, can be used to applications outside of ophthalmology such as detection and characterization of skin cancer for example. Keratoconus is a disease that weakens the cornea resulting in loss of corneal shape which in turn distorts the eye's ability to focus. We are developing high resolution three-dimensional ultrasound elasticity imaging which can detect the onset of keratoconus, monitor progression of this disease, and in its late stage aid corneal transplant surgery.
