Refractive changes of a new asymmetric intracorneal ring segment with variable thickness and base width: a 2D finite-element model
Author
García de Oteyza, Gonzalo
Álvarez de Toledo, Juan
Barraquer, Rafael I.
Kling, Sabine
Publication date
2021ISSN
1932-6203
Abstract
Purpose: To evaluate the local geometric effects of a unilateral intrastromal ring segment with a combined variation of ring thickness and base width in a finite element simulation, and to compare it against the isolated effect of thickness or base width variation alone. Methods: A two-dimensional finite-element model of a transversely isotropic cornea was created assuming either axisymmetric stress or plane strain condition. The model geometry was composed of a three-layered corneal tissue (epithelium, anterior and posterior stroma) fixed at the limbus. The implantation of a triangular-shape asymmetric ring segment with varying ring thickness (150 to 300 μm) and base width (600 to 800 μm) was simulated. Also, changes induced by thickness or base width alone were studied and compared their combined effect in the asymmetric ring segment. Geometrical deformation of the simulated cornea and sagittal curvature were the main parameters of study. Results: Increasing ring thickness and base width along the arc of the asymmetric ring segment produced a more pronounced flattening in this part of the ring. The asymmetric design did find a good balance between maximizing corneal flattening at one end and minimizing it at the other end, compared to the isolated effect of ring thickness and width. Ring thickness was the most robust parameter in flattening both, the central and peripheral cornea. Conclusion: The finite-element model permitted a theoretical study of corneal deformation undergoing implantation of realistic and hypothetical ring geometries. Intracorneal asymmetric ring segments with varying thickness and base width can be a good alternative in corneas with asymmetric keratoconus phenotypes.
Document Type
Article
Document version
Published version
Language
English
Subject (CDU)
617 - Surgery. Orthopaedics. Ophthalmology
Keywords
Oftalmologia
Oftalmología
Ophthalmology
Pages
14
Publisher
Public Library of Science
Collection
16; 9
Is part of
PLoS ONE
Citation
García de Oteyza, Gonzalo; Álvarez de Toledo, Juan; Barraquer, Rafael I. [et al.]. Refractive changes of a new asymmetric intracorneal ring segment with variable thickness and base width: a 2D finite-element model. PLoS ONE, 2021, 16(9), e0257222. Disponible en: <https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0257222>. Fecha de acceso: 14 feb. 2024. DOI: 10.1371/journal.pone.0257222
This item appears in the following Collection(s)
- Ciències de la Salut [745]
Rights
© 2021 García de Oteyza et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Except where otherwise noted, this item's license is described as https://creativecommons.org/licenses/by/4.0/