Official ESCRS | European Society of Cataract & Refractive Surgeons


Finite element simulation of tomographic parameters of keratectasia

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Session Details

Session Title: Keratoconus

Session Date/Time: Monday 16/09/2019 | 14:00-16:00

Paper Time: 14:00

Venue: Free Paper Forum: Podium 2

First Author: : H.Studer SWITZERLAND

Co Author(s): :    T. Koller   M. Jankov   E. Businaro   T. Seiler                    

Abstract Details


To simulate keratoconus (KCN) and pellucid marginal degeneration (PMD) using finite element modelling (FEM).


Institut für Refraktive und Ophthalmo-Chirurgie (IROC), Zürich, Switzerland


FEM simulated a focal weakening of the elastic modulus (20 to 65%) and pachymetry (20%) using a gaussian profile at various eccentricities ranging from 0 to 4mm in 0.5mm steps. Simulated corneal tomographies were evaluated for aberrations using Zernike polynomials and tomographic parameters. Statistical differences in keratometric astigmatism, astigmatic- and spherical aberration, and coma of 1st order were determined to these 8 eccentricities.


All functions of aberrations had defined maxima: keratometric astigmatism at a eccentricity of 2.0mm, astigmatic aberration at 2.5mm, Coma at 1.0mm and spherical aberration at 0.0mm. Topographical appearance of paracentral weakening revealed KCN-like patterns. Starting in the periphery the pattern looked PMD-like.


Focal weakening of the cornea may produce KCN-like patterns as well as PMD-like patterns for different eccentricities.

Financial Disclosure:

is employed by a for profit company with an interest in the subject of the presentation

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