Simulating the Insertion of Intrastromal Corneal Ring Segments in Keratoconic Corneas

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Dashti, Azadeh | 2016

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Type of Document: M.Sc. Thesis
Language: Farsi
Document No: 48948 (08)
University: Sharif University of Technology
Department: Mechanical Engineering
Advisor(s): Zohoor, Hassan; Ahmadian, Mohammad Taghi
Abstract:
Keratoconus is a progressive corneal illness that appears due to reduced thickness of cornea in some area. Normal cornea has semi sphere shape with uniform thickness from center of cornea to the limbus. However, keratoconic cornea’s shape becomes conic. One of the treatments in moderate state of keratoconus is implantation of IntraStromal Corneal Ring Segments( ICRS). Ring Segments are made of PMMA and inserted in 0/7- 0/8 of depth of cornea.In this study, before surgery data from 3 patient’s cornea images were prepared in order to 3D modeling of cornea, for importing to FEM software( ABAQUS). Material properties of cornea is considered hyperelastic second-order Ogden Model; elastic constants are used in this study as those were reported in previous study. Ring Segments are stiffer than cornea, hence they are considered as rigid bodies. For simulation of Ring Segment insertion in cornea, Ring will be inserted in a cut that is created in depth, position and width which surgeons make in real surgeries.For validation, we will compare results with previous study that shows our modeling of Ring Insertion is acceptable
Keywords:
Hyperelasticity ; Hyperelastic Materials ; Finite Element Simulation ; Intra Stromal Corneal Ring Segment ; Keratocanic Corneas