Finite Element Modelling Of Geometrical Factors Affecting Descemet's Membrane Endothelial Keratoplasty (Dmek) Graft Adherence
Published 2023 - 41st Congress of the ESCRS
Reference: PP24.08 | Type: Free paper | DOI: 10.82333/etfq-3002
Authors: Yoav Nahum* 1 , Edward Barayev 1 , Dor Berla 2 , Shmuel Minervi 2 , Irit Bahar 1 , Daniel Portnoy 2
1Ophthalmology,Rabin Medical Center,Petach Tikva,Israel;Sackler faculty of Medicine,Tel Aviv University,Tel Aviv,Israel, 2School of Mechanical Engineering,Tel Aviv University,Tel Aviv,Israel
Purpose
To perform and Finite element method (FEM) modelling of geometrical factors affecting DMEK graft adherence to the recipient cornea
Setting
In Silico study
Methods
Solidworks CAD software and ANSYS analysis software were used to create a theoretical 3D model of the posterior surface of the recipient cornea, and of a DMEK graft. Simulation of stress distribution and deformations were modelled on grafts of different diameters, shapes (round, elliptical and hexagonal), and locations.
Results
In round and elliptical grafts, the largest deformations were observed on the edges of the horizontal meridian. For all graft shapes, deformations favoring detachment were decreased with increased graft diameter. Elliptical graft of 6X8mm diameters, aligned with the posterior corneal astigmatism, showed the lowest mechanical stress values of all shapes. Maximal stress value of this graft was only 42.4% of that of a round, centered 8mm graft. (6.7Pa versus 15.8Pa). Both mean and maximal deformation values were higher in the decentered round grafts in comparison to centered ones.
Conclusions
A centered, elliptical, large graft, oriented with the curvatures of the posterior cornea is optimal for prevention of graft detachment, the most common early complication of DMEK.