| Popis: |
The biomechanical properties of the cornea are an important determinant of both the shape and function of the human visual system. Measuring the biomechanical properties on an in vivo basis requires the development of technologies not typically associated with mechanical measurement. Optical Coherence Elastography (OCE) is an optical based measurement capable of measuring micron level displacements in accessible tissues. The application of OCE to corneal measurement was made possible by the use of speckle tracking in the corneal stroma. Application of OCE to human donor corneas was used to measure the biomechanical properties of the human cornea in three separate states: edematous, normal or deturgessed, and post crosslinking (CXL). The corneal mechanical properties were shown to increase in stiffness in each of the three states, from least stiff when edematous to most stiff post CXL. The early stages of the development of Doppler Shear Wave Optical Coherence Elastography to measure mechanical properties without the need for additional modeling and inferences. The technique utilizes the Doppler shift of a shear wave as it is scanned by OCE to measure the Shear Modulus and Young’s modulus of the tissue. As a technique that can be performed on a single two dimensional scan of the tissue, it is suitable for high speed in vivo use. OCE provides a promising tool for measuring the biomechanical properties of the cornea under in vivo conditions. |
