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In vivo measurements of normal, keratoconic, and post crosslinked keratoconic human cornea with optical coherence elastography (Conference Presentation)

Paper Abstract

Purpose: To measure the spatially resolved compressive stiffness properties under in vivo conditions to evaluate the effects of clinical corneal crosslinking (CXL) on patients with keratoconus. Methods: Patients with keratoconus who were scheduled to undergo CXL were imaged before (<1 week) and after (3 to 6 months) treatment. The study was approved under the Cleveland Clinic Institutional Review Board (IRB #13-213). The imaging procedure consists of a continuous compression with a flat glass plate while imaging with swept-source OCT. The frame-to-frame displacements were measured using speckle tracking. Maps of the first order fit of applied force vs cumulative axial displacement were created. Spatially averaged central anterior and posterior regions were defined to generate a relative stiffness value (k) expressing anterior properties relative to posterior stromal properties. Data previously collected from normal patients were also used for group comparison purposes. Results: Qualitative comparison of the color map representation showed significant differences in the distribution of compressive mechanical properties between all three patient types. Mean k-value were 1.129 ± 0.067 in normal eyes (n=12), 0.988 ± 0.089 in keratoconus eyes (n=8), and 1.27 ± 0.16 in keratoconus eyes after CXL (n=6, p<0.05 for all groups using Mann-Whitney U test). Conclusions: The spatial biomechanical effects of CXL are measurable with in vivo compressive OCE. The normal anterior to posterior stromal force/displacement ratio appears to be reduced in keratoconus and is increased to or even beyond normal levels after CXL due to selective stiffening of the anterior stroma.

Paper Details

Date Published: 13 March 2019
Proc. SPIE 10880, Optical Elastography and Tissue Biomechanics VI, 108800X (13 March 2019); doi: 10.1117/12.2507996
Show Author Affiliations
Matthew R. Ford, Cole Eye Institute, Cleveland Clinic (United States)
Vinicius S. DeStefano, Univ. Federal de São Paulo (Brazil)
Ibrahim Seven, Cole Eye Institute, Cleveland Clinic (United States)
William J. Dupps Jr., Cole Eye Institute, Cleveland Clinic (United States)

Published in SPIE Proceedings Vol. 10880:
Optical Elastography and Tissue Biomechanics VI
Kirill V. Larin; Giuliano Scarcelli, Editor(s)

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