title: Measurement of corneal elasticity with an acoustic radiation force elasticity microscope.
abstract: To investigate the role of collagen structure in corneal biomechanics, measurement of localized corneal elasticity with minimal destruction to the tissue is necessary. We adopted the recently developed acoustic radiation force elastic microscopy (ARFEM) technique to measure localize biomechanical properties of the human cornea. In ARFEM, a low-frequency, high-intensity acoustic force is used to displace a femtosecond laser-generated microbubble, while high-frequency, low-intensity ultrasound is used to monitor the position of the microbubble within the cornea. Two ex vivo human corneas from a single donor were dehydrated to physiologic thickness, embedded in gelatin and then evaluated using the ARFEM technique. In the direction perpendicular to the corneal surface, ARFEM measurements provided elasticity values of E = 1.39 ± 0.28 kPa for the central anterior cornea and E = 0.71 ± 0.21 kPa for the central posterior cornea in pilot studies. The increased value of corneal elasticity in the anterior cornea correlates with the higher density of interweaving lamellae in this region.
authors.affiliation: Department of Biomedical Engineering, University of California, Irvine, Irvine, California, USA. Electronic address: emikula@uci.edu.
authors.forename: Eric
authors.initials: E
authors.lastname: Mikula
authors.affiliation: Department of Biomedical Engineering, University of Michigan, Ann Arbor, Michigan, USA; Soundsight Research, Livonia, Michigan, USA.
authors.forename: Kyle
authors.initials: K
authors.lastname: Hollman
authors.affiliation: Gavin Herbert Eye Institute, University of California, Irvine, Irvine, California, USA.
authors.forename: Dongyul
authors.initials: D
authors.lastname: Chai
authors.affiliation: Department of Biomedical Engineering, University of California, Irvine, Irvine, California, USA; Gavin Herbert Eye Institute, University of California, Irvine, Irvine, California, USA.
authors.forename: James V
authors.initials: JV
authors.lastname: Jester
authors.affiliation: Department of Biomedical Engineering, University of California, Irvine, Irvine, California, USA; Gavin Herbert Eye Institute, University of California, Irvine, Irvine, California, USA.
authors.forename: Tibor
authors.initials: T
authors.lastname: Juhasz
mesh_terms: D000465:Algorithms; D002102:Cadaver; D003198:Computer Simulation; D003315:Cornea / Q000000981:diagnostic imaging* / Q000502:physiology*; D003941:Diagnostic Techniques, Ophthalmological; D055119:Elastic Modulus / Q000502:physiology; D054459:Elasticity Imaging Techniques / Q000379:methods*; D006245:Hardness Tests / Q000379:methods*; D006801:Humans; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D066298:In Vitro Techniques; D033401:Microscopy, Acoustic / Q000379:methods*; D008954:Models, Biological; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity
keywords: Biomechanics; Cornea; Elastic modulus; Elasticity; High-intensity focused ultrasound; Ultrasound
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