Determination of Corneal Biomechanical Behavior <i>in</i>-<i>vivo</i> for Healthy Eyes Using CorVis ST Tonometry: Stress-Strain Index

Eliasy, Ashkan ORCID: 0000-0002-4473-1900, Chen, Kai-Jung ORCID: 0000-0003-4940-6856, Vinciguerra, Riccardo, Lopes, Bernardo T ORCID: 0000-0002-8489-3621, Abass, Ahmed ORCID: 0000-0002-8622-4632, Vinciguerra, Paolo, Ambrosio, Renato Jr, Roberts, Cynthia J and Elsheikh, Ahmed ORCID: 0000-0001-7456-1749 (2019) Determination of Corneal Biomechanical Behavior <i>in</i>-<i>vivo</i> for Healthy Eyes Using CorVis ST Tonometry: Stress-Strain Index. FRONTIERS IN BIOENGINEERING AND BIOTECHNOLOGY, 7 (MAY). 105-.

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Abstract

<b>Purpose:</b> This study aims to introduce and clinically validate a new algorithm that can determine the biomechanical properties of the human cornea <i>in vivo</i>. <b>Methods:</b> A parametric study was conducted involving representative finite element models of human ocular globes with wide ranges of geometries and material biomechanical behavior. The models were subjected to different levels of intraocular pressure (IOP) and the action of external air puff produced by a non-contact tonometer. Predictions of dynamic corneal response under air pressure were analyzed to develop an algorithm that can predict the cornea's material behavior. The algorithm was assessed using clinical data obtained from 480 healthy participants where its predictions of material behavior were tested against variations in central corneal thickness (CCT), IOP and age, and compared against those obtained in earlier studies on <i>ex-vivo</i> human ocular tissue. <b>Results:</b> The algorithm produced a material stiffness parameter (Stress-Strain Index or SSI) that showed no significant correlation with both CCT (<i>p</i> > 0.05) and IOP (<i>p</i> > 0.05), but was significantly correlated with age (<i>p</i> < 0.01). The stiffness estimates and their variation with age were also significantly correlated (<i>p</i> < 0.01) with stiffness estimates obtained earlier in studies on <i>ex-vivo</i> human tissue. <b>Conclusions:</b> The study introduced and validated a new method for estimating the <i>in vivo</i> biomechanical behavior of healthy corneal tissue. The method can aid optimization of procedures that interfere mechanically with the cornea such as refractive surgeries and introduction of corneal implants.

Item Type:	Article
Uncontrolled Keywords:	cornea, biomechanics, material properties, numerical modeling, finite element modeling
Depositing User:	Symplectic Admin
Date Deposited:	15 Jul 2019 07:58
Last Modified:	14 Oct 2023 09:13
DOI:	10.3389/fbioe.2019.00105
Open Access URL:	https://doi.org/10.3389/fbioe.2019.00105
Related URLs:	Author Publisher
URI:	https://livrepository.liverpool.ac.uk/id/eprint/3048734

Available Versions of this Item

• Determination of Corneal Biomechanical Behaviour In-vivo for Healthy Eyes Using CorVis ST Tonometry: Stress-Strain Index. (deposited 20 May 2019 11:30)
  • Determination of Corneal Biomechanical Behavior in-vivo for Healthy Eyes Using CorVis ST Tonometry: Stress-Strain Index. (deposited 29 May 2019 09:32)
    • Determination of Corneal Biomechanical Behavior <i>in</i>-<i>vivo</i> for Healthy Eyes Using CorVis ST Tonometry: Stress-Strain Index. (deposited 15 Jul 2019 07:58) [Currently Displayed]