title: Evaluation of the mechanical behaviour and estimation of the elastic properties of porcine zonular fibres.
abstract: The mechanical behaviour of zonular fibres greatly affects the accommodation process in mammalian eyes. This paper introduces a detailed measurement procedure for the purpose of obtaining the force-displacement diagram necessary to evaluate the mechanical properties of porcine zonular fibres in situ. It is a complex technique, keeping the integrity of the zonular bundles between the crystalline lens and the ciliary muscle cells. We present a brief description of the measurement procedure both in theory and in practice, along with the force-displacement diagrams acquired from a porcine sample group. The strengths of this newly developed method are the unequivocal force transmission between the sample and the transducer, and the intact connection between the ciliary body and the crystalline lens via zonular fibres. With the aid of these measurements, we define an estimated material model for the zonular apparatus both analytically and using the finite element method. The two different evaluation methods show close agreement in the calculated Young's modulus for the zonular fibres. The range of the calculated elastic modulus is 200-250 kPa. This new measuring method is adaptable to human specimens. Despite its complexity, the entire procedure and the evaluation part are reproducible. The constitutive model aims to shed light on the mechanics of the accommodation process.
authors.affiliation: Budapest University of Technology and Economics, Faculty of Civil Engineering, Department of Structural Mechanics, Budapest, Hungary. Electronic address: zbocskai@mail.bme.hu.
authors.forename: Zoltán I
authors.initials: ZI
authors.lastname: Bocskai
authors.affiliation: Semmelweis University, Faculty of Medicine, Department of Ophthalmology, Budapest, Hungary.
authors.forename: Gábor L
authors.initials: GL
authors.lastname: Sándor
authors.affiliation: Budapest University of Technology and Economics, Faculty of Mechanical Engineering, Department of Polymer Engineering, Budapest, Hungary.
authors.forename: Zoltán
authors.initials: Z
authors.lastname: Kiss
authors.affiliation: Budapest University of Technology and Economics, Faculty of Civil Engineering, Department of Structural Mechanics, Budapest, Hungary.
authors.forename: Imre
authors.initials: I
authors.lastname: Bojtár
authors.affiliation: Semmelweis University, Faculty of Medicine, Department of Ophthalmology, Budapest, Hungary.
authors.forename: Zoltán Z
authors.initials: ZZ
authors.lastname: Nagy
mesh_terms: D000065:Accommodation, Ocular; D000818:Animals; D001696:Biomechanical Phenomena; D002924:Ciliary Body / Q000166:cytology / Q000502:physiology; D055119:Elastic Modulus; D020342:Finite Element Analysis; D007908:Lens, Crystalline / Q000166:cytology / Q000502:physiology; D008422:Materials Testing / Q000379:methods*; D032342:Muscle Cells / Q000166:cytology; D013552:Swine
keywords: Biomechanics; Force–displacement diagram; Material property; Porcine eye; Zonular fibres