Stress free configuration of the human eye

Elsheikh, Ahmed; Whitford, Charles; Hamarashid, Rosti; Kassem, Wael; Joda, Akram; Büchler, Philippe (2012). Stress free configuration of the human eye. Medical engineering & physics, 35(2), pp. 211-216. Amsterdam: Elsevier 10.1016/j.medengphy.2012.09.006

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Numerical simulations of eye globes often rely on topographies that have been measured in vivo using devices such as the Pentacam or OCT. The topographies, which represent the form of the already stressed eye under the existing intraocular pressure, introduce approximations in the analysis. The accuracy of the simulations could be improved if either the stress state of the eye under the effect of intraocular pressure is determined, or the stress-free form of the eye estimated prior to conducting the analysis. This study reviews earlier attempts to address this problem and assesses the performance of an iterative technique proposed by Pandolfi and Holzapfel [1], which is both simple to implement and promises high accuracy in estimating the eye's stress-free form. A parametric study has been conducted and demonstrated reliance of the error level on the level of flexibility of the eye model, especially in the cornea region. However, in all cases considered 3-4 analysis iterations were sufficient to produce a stress-free form with average errors in node location <10(-6)mm and a maximal error <10(-4)mm. This error level, which is similar to what has been achieved with other methods and orders of magnitude lower than the accuracy of current clinical topography systems, justifies the use of the technique as a pre-processing step in ocular numerical simulations.

Item Type:	Journal Article (Original Article)
Division/Institute:	04 Faculty of Medicine > Pre-clinic Human Medicine > Institute for Surgical Technology & Biomechanics ISTB [discontinued]
UniBE Contributor:	Büchler, Philippe
Subjects:	500 Science > 570 Life sciences; biology 600 Technology > 610 Medicine & health
ISSN:	1350-4533
Publisher:	Elsevier
Language:	English
Submitter:	Philippe Büchler
Date Deposited:	04 Oct 2013 14:30
Last Modified:	05 Dec 2022 14:09
Publisher DOI:	10.1016/j.medengphy.2012.09.006
PubMed ID:	23041490
Web of Science ID:	000314382700009
URI:	https://boris.unibe.ch/id/eprint/11454 (FactScience: 217621)