title: Optical coherence elastography assessment of corneal viscoelasticity with a modified Rayleigh-Lamb wave model.
abstract: The biomechanical properties of the cornea play a critical role in forming vision. Diseases such as keratoconus can structurally degenerate the cornea causing a pathological loss in visual acuity. UV-A/riboflavin corneal collagen crosslinking (CXL) is a clinically available treatment to stiffen the cornea and restore its healthy shape and function. However, current CXL techniques do not account for pre-existing biomechanical properties of the cornea nor the effects of the CXL treatment itself. In addition to the inherent corneal structure, the intraocular pressure (IOP) can also dramatically affect the measured biomechanical properties of the cornea. In this work, we present the details and development of a modified Rayleigh-Lamb frequency equation model for quantifying corneal biomechanical properties. After comparison with finite element modeling, the model was utilized to quantify the viscoelasticity of in situ porcine corneas in the whole eye-globe configuration before and after CXL based on noncontact optical coherence elastography measurements. Moreover, the viscoelasticity of the untreated and CXL-treated eyes was quantified at various IOPs. The results showed that the stiffness of the cornea increased after CXL and that corneal stiffness is close to linear as a function of IOP. These results show that the modified Rayleigh-Lamb wave model can provide an accurate assessment of corneal viscoelasticity, which could be used for customized CXL therapies.
authors.affiliation: Department of Biomedical Engineering, University of Houston, Houston, TX 77204, United States.
authors.forename: Zhaolong
authors.initials: Z
authors.lastname: Han
authors.affiliation: Department of Biomedical Engineering, University of Houston, Houston, TX 77204, United States.
authors.forename: Jiasong
authors.initials: J
authors.lastname: Li
authors.affiliation: Department of Biomedical Engineering, University of Houston, Houston, TX 77204, United States.
authors.forename: Manmohan
authors.initials: M
authors.lastname: Singh
authors.affiliation: Department of Biomedical Engineering, University of Houston, Houston, TX 77204, United States.
authors.forename: Chen
authors.initials: C
authors.lastname: Wu
authors.affiliation: Department of Biomedical Engineering, University of Houston, Houston, TX 77204, United States.
authors.forename: Chih-Hao
authors.initials: CH
authors.lastname: Liu
authors.affiliation: Department of Biomedical Engineering, University of Houston, Houston, TX 77204, United States.
authors.forename: Raksha
authors.initials: R
authors.lastname: Raghunathan
authors.affiliation: Department of Biomedical Engineering, University of Texas at Austin, Austin, TX 78712, United States.
authors.forename: Salavat R
authors.initials: SR
authors.lastname: Aglyamov
authors.affiliation: College of Optometry, University of Houston, Houston, TX 77204, United States.
authors.forename: Srilatha
authors.initials: S
authors.lastname: Vantipalli
authors.affiliation: School of Optometry, University of Alabama at Birmingham, Birmingham, AL 35233, United States.
authors.forename: Michael D
authors.initials: MD
authors.lastname: Twa
authors.affiliation: Department of Biomedical Engineering, University of Houston, Houston, TX 77204, United States; Interdisciplinary Laboratory of Biophotonics, Tomsk State University, Tomsk, Russia; Department of Molecular Physiology and Biophysics, Baylor College of Medicine, Houston, TX 77030, United States. Electronic address: klarin@central.uh.edu.
authors.forename: Kirill V
authors.initials: KV
authors.lastname: Larin
mesh_terms: D000818:Animals; D001696:Biomechanical Phenomena; D003094:Collagen; D003315:Cornea / Q000000981:diagnostic imaging*; D003432:Cross-Linking Reagents; D054459:Elasticity Imaging Techniques; D007640:Keratoconus; D012256:Riboflavin; D013552:Swine; D014065:Tonometry, Ocular; D014466:Ultraviolet Rays
chemical_list: D003432:Cross-Linking Reagents; D003094:Collagen; D012256:Riboflavin
keywords: Cornea; Crosslinking; Intraocular pressure; Modified Rayleigh-Lamb frequency equation; Optical coherence elastography; Viscoelasticity