Iranian Journal of Biomedical Engineering (IJBME)
نشریه علمی مهندسی پزشکی زیستی

A Comparative Study on Common Scenarios of Single-Segment and Double-Segment Intracorneal Ring Segments in a Keratoconus Corneal Model

Document Type : Full Research Paper

Authors

Shima Bahramizadeh-Sajadi 1
Hamid Reza Katoozian 2
Alireza Baradaran-Rafii‬‬‬‬‬‬‬ 3
Miguel-Angel Ariza-Gracia 4
Philippe Buchler 5

1 Ph.D. Student, Department of Biomedical Engineering, Amirkabir University of Technology (Tehran Polytechnic), Tehran,

2 Associate Professor, Department of Biomedical Engineering, Amirkabir University of Technology (Tehran Polytechnic), Tehran, Iran

3 Professor, Ophthalmic Research Center, Shahid Beheshti University of Medical Sciences, Tehran, Iran

4 Postdoctoral Fellow, ARTORG Center for Biomedical Engineering Research, University of Bern, Bern, Switzerland

5 Professor, ARTORG Center for Biomedical Engineering Research, University of Bern, Bern, Switzerland

https://doi.org/10.22041/ijbme.2022.544471.1738
Abstract
Keratoconus (KC) is a non-inflammatory and degenerative disease of the cornea. It is manifested by the formation of cone-shaped regions accompanying severe eyesight issues. Implantation of intrastromal corneal ring segments (ICRS)‎ is a popular treatment to improve visual acuity. Controversies exist over restoring functionality of different ICRSs. In this study, numerical models were used to quantify the mechanical and optical effects of different ICRSs on a reference cornea with central cone. Finite element (FE) simulations were used to simulate the implantation of two classes of ICRS sets common in clinical settings: a) single segment arcs of 360º (1×360), 350º (1×350), 320º (1×320), and, b) symmetric double-segment arcs of 160º each (2×160), 150º each (2×150), 120º each (2×120), and 90º each (2×90). Results showed that implantation of symmetric double-segment arcs caused the symmetric displacement and stress distribution contours on both anterior and posterior corneal surfaces. This study shows the potential impact of a detailed mechanical analysis of ICRS placement and represents a first step toward the development of an evidence-based nomogram for the different implantation techniques and the optimization of the surgical intervention based on patient-specific modeling.

Keywords

Keratoconic Cornea
Finite Element Method
Ocular Biomechanics
Stress Distribution
Displacement Distribution

Subjects

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Iranian Journal of Biomedical Engineering (IJBME)
Volume 15, Issue 4
Winter 2022
Pages 329-339

  • Receive Date 08 December 2021
  • Revise Date 29 January 2022
  • Accept Date 13 February 2022

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