Posters

Predictive analysis of accommodation and biomechanics of ciliary muscle forces utilizing 3D finite element model

Poster Details

First Author: A.Hipsley USA

Co Author(s):    S. Blemker   K. Knaus   D. Goldberg              

Abstract Details

Purpose:

To develop a multi-component 3D finite element model (FEM) of the accommodative mechanism that includes the extralenticular and lenticular anatomy capable of performing whole eye accommodation simulations suitable for testing therapeutic and surgical applications.

Setting:

A novel physics-based computer simulation; Biomedical Engineering Department, University of Virginia.

Methods:

After an extensive literature review to define the anatomical geometry and material properties of young and old resting human eye, we developed representative 3D models of the ocular structures. Geometric meshing and FEM analysis were performed using advanced multi-physics simulation (AMPS) technology on representative 3D models of ocular structures. These simulated zonular pre-tensioning of the lens to the unaccommodated state and ciliary muscle contraction to the accommodated state. Ciliary muscle fiber groups were activated in isolation to quantify each�â�€�™s contribution to accommodative action. Model predictions for surgical intervention and therapies were analyzed including scleral treatments and accommodating intraocular lenses.

Results:

FEM predicted lens deformations and displacements related to accommodative amplitude changes that were consistent with experimental observations from the literature. FEM demonstrated contractile forces of the ciliary muscle and the resultant changes to the ocular structures during accommodation. FEM revealed specific contributions of ciliary fiber groups to lens changes, with circular fibers contributing most to circumferential deformation, and radial fibers contributing most to anterior displacement. Sensitivity analysis of the differences in accommodation between the �â�€�œyoung/healthy�â�€� and �â�€�œold/presbyobic�â�€� eye identified the age-related changes that contribute most to symptoms of presbyopia. Virtual surgical and therapeutic applications were also simulated revealing biomechanical implications.

Conclusions:

This computational 3D FEM provides novel insight into the interactions and biomechanics of the components of the accommodative mechanism through incorporation of decades of previous research. The model results were effectively validated with existing data and illuminated interesting and critical information about the impact of age on ocular biomechanical structures and accommodative responses. Virtual surgical and therapeutic simulations could provide novel insight to new technology applications in presbyopia.

Financial Disclosure:

gains financially from product or procedure presented, receives consulting fees, retainer, or contract payments from a company producing, developing or supplying the product or procedure presented