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Proceedings Paper

FEM simulation of the human lens compared to ex vivo porcine lens cutting pattern: a possible treatment of presbyopia
Author(s): T. Ripken; P. Breitenfeld; M. Fromm; U. Oberheide; G. Gerten; H. Lubatschowski
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Paper Abstract

The most probable reason for presbyopia is an age related loss of elasticity of the lens. It progresses typically during the whole life and at the age of about 45 it leads to a considerable loss of the ability to accommodate within the next decade. However, both, the ciliary muscle and the lens capsule stay active and elastic, respectively. With respect to this, one concept is to regain the deformability of the lens without changing the capsule or zonular apparatus. Since the investigations of Ripken et al. proofed that the flexibility of the presbyopic lens tissue can be increased through the creation of fs-laser induced microcuts inside the lens, this is one possible approach to treat presbyopia. On this account a finite-element-method model with ANSYS of the human lens during accommodation will be presented. The analysis premises all lens materials to be linear elastic and allow large displacements. A first analysis of this method for the treatment of presbyopia is accomplished. Therefore the mechanical analysis of untreated and treated lens are compared. In addition ex-vivo elasticity measurements of untreated and treated lenses will be presented. As a result an improvement of the flexibility of the lens tissue is found and as its consequence a change of the lens radii of curvature is established. After suitable processing of the output data the change in optical power between untreated and treated lenses are calculated. The finite element simulation shows similar behaviour compared to the treated porcine lenses.

Paper Details

Date Published: 7 March 2006
PDF: 11 pages
Proc. SPIE 6138, Ophthalmic Technologies XVI, 613819 (7 March 2006); doi: 10.1117/12.646635
Show Author Affiliations
T. Ripken, Laser Zentrum Hannover e.V. (Germany)
P. Breitenfeld, Laser Zentrum Hannover e.V. (Germany)
M. Fromm, Laser Zentrum Hannover e.V. (Germany)
U. Oberheide, Laserforum Köln e.V. (Germany)
G. Gerten, Laserforum Köln e.V. (Germany)
H. Lubatschowski, Laser Zentrum Hannover e.V. (Germany)


Published in SPIE Proceedings Vol. 6138:
Ophthalmic Technologies XVI
Fabrice Manns; Per G. Söderberg; Arthur Ho, Editor(s)

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