title: A quantitative ultrasonic spectroscopy method for noninvasive determination of corneal biomechanical properties.
abstract: OBJECTIVE
  To describe a quantitative ultrasonic spectroscopy technique for the noninvasive characterization of corneal biomechanical properties and to compare these measurements with established techniques in a porcine eye model.
  
  
  METHODS
  An ultrasound system was constructed to accurately acquire acoustic reflections from corneas through a saline bath. Corneal properties (including thickness, density and aggregate modulus) were estimated from the measured reflection spectra based on wave propagation analysis. Twenty fresh porcine corneas were measured using the quantitative ultrasound method and other established techniques that can only be applied to dissected corneas.
  
  
  RESULTS
  The ultrasonic measurements of corneal thickness and aggregate modulus were significantly correlated with the measurements of established techniques (Pearson's correlation = 0.99 and 0.61; P < 0.005), and good sample-to-sample consistency was achieved. The measurement of corneal density agreed well in terms of mean and range, but the correlation did not achieve statistical significance (Pearson's correlation = 0.41; P = 0.07).
  
  
  CONCLUSIONS
  The ultrasonically measured corneal biomechanical properties agreed well with the measurements obtained by using established techniques, validating the accuracy of the ultrasound method. Quantitative ultrasound spectroscopy may provide a noninvasive approach for in vivo characterization of corneal biomechanical properties.
authors.affiliation: Department of Biomedical Engineering, Ohio State University, Columbus, Ohio, USA.
authors.forename: Xiaoyin
authors.initials: X
authors.lastname: He
authors.forename: Jun
authors.initials: J
authors.lastname: Liu
mesh_terms: D000818:Animals; D001696:Biomechanical Phenomena / Q000502:physiology; D003315:Cornea / Q000000981:diagnostic imaging* / Q000502:physiology*; D004547:Elastic Tissue / Q000000981:diagnostic imaging / Q000502:physiology; D004548:Elasticity / Q000502:physiology*; D033401:Microscopy, Acoustic; D013057:Spectrum Analysis; D013552:Swine