{"title":"Biomechanical evaluation of different plunger size and plunger position on removing soft contact lenses and rigid gas permeable contact lenses.","authors":"Min-Chien Hsiao, Yu-Chun Yen, Chun-Hsiang Wang, Yen-Nien Chen, Shun-Ping Wang, Kuo-Chih Su","doi":"10.3233/THC-231983","DOIUrl":null,"url":null,"abstract":"<p><strong>Background: </strong>To avoid risks of mucosal infection from contact lenses removal, a contact lens plunger is often used.</p><p><strong>Objective: </strong>Given various types of contact lens plungers available on the market, no study has yet been done on mechanical effects of the contact lens plunger on contact lens removal. Here, this study used finite element analysis to investigate the effects of plunger size and plunger position on the removal of soft and rigid gas permeable (RGP) contact lenses.</p><p><strong>Methods: </strong>First, we established finite element analysis models for the plunger, contact lens, cornea, and aqueous humor. The plunger is made of mostly silicone rubber, and the contact lenses are mainly made of soft and hard material. The part of the plunger used for removal was located either at the central or the edged position, with pulling 1 mm distance. The main parameters observation indicators of in this study were the reaction force at the fixed end of the cornea, aqueous humor, the von Mises stress of the plunger, the contact lenses, and the cornea.</p><p><strong>Results: </strong>Results of this study showed that when a plunger of a larger diameter was used, the reaction force of the plunger was also larger, especially when applied to RGP lenses, which required a slightly larger force (∼0.27 N). Also, when removing a RGP lens from the edge, there was a greater stress at the edge of the contact lens (2.5799 MPa), and this caused a higher stress on both the cornea (0.0165 MPa) and the aqueous humor (0.00114 MPa).</p><p><strong>Conclusions: </strong>When using a plunger with a larger diameter to remove a RGP lens, although a larger force required, the relatively larger contact area likely reduced the stress on the cornea and aqueous humor, thereby reducing the risk of eye injury. In addition, when removing a RGP lens, the results of this study recommended it to be removed from the plunger edge, as that facilitated the removal of contact lens.</p>","PeriodicalId":48978,"journal":{"name":"Technology and Health Care","volume":null,"pages":null},"PeriodicalIF":1.4000,"publicationDate":"2024-07-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Technology and Health Care","FirstCategoryId":"5","ListUrlMain":"https://doi.org/10.3233/THC-231983","RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q4","JCRName":"ENGINEERING, BIOMEDICAL","Score":null,"Total":0}
引用次数: 0
Abstract
Background: To avoid risks of mucosal infection from contact lenses removal, a contact lens plunger is often used.
Objective: Given various types of contact lens plungers available on the market, no study has yet been done on mechanical effects of the contact lens plunger on contact lens removal. Here, this study used finite element analysis to investigate the effects of plunger size and plunger position on the removal of soft and rigid gas permeable (RGP) contact lenses.
Methods: First, we established finite element analysis models for the plunger, contact lens, cornea, and aqueous humor. The plunger is made of mostly silicone rubber, and the contact lenses are mainly made of soft and hard material. The part of the plunger used for removal was located either at the central or the edged position, with pulling 1 mm distance. The main parameters observation indicators of in this study were the reaction force at the fixed end of the cornea, aqueous humor, the von Mises stress of the plunger, the contact lenses, and the cornea.
Results: Results of this study showed that when a plunger of a larger diameter was used, the reaction force of the plunger was also larger, especially when applied to RGP lenses, which required a slightly larger force (∼0.27 N). Also, when removing a RGP lens from the edge, there was a greater stress at the edge of the contact lens (2.5799 MPa), and this caused a higher stress on both the cornea (0.0165 MPa) and the aqueous humor (0.00114 MPa).
Conclusions: When using a plunger with a larger diameter to remove a RGP lens, although a larger force required, the relatively larger contact area likely reduced the stress on the cornea and aqueous humor, thereby reducing the risk of eye injury. In addition, when removing a RGP lens, the results of this study recommended it to be removed from the plunger edge, as that facilitated the removal of contact lens.
期刊介绍:
Technology and Health Care is intended to serve as a forum for the presentation of original articles and technical notes, observing rigorous scientific standards. Furthermore, upon invitation, reviews, tutorials, discussion papers and minisymposia are featured. The main focus of THC is related to the overlapping areas of engineering and medicine. The following types of contributions are considered:
1.Original articles: New concepts, procedures and devices associated with the use of technology in medical research and clinical practice are presented to a readership with a widespread background in engineering and/or medicine. In particular, the clinical benefit deriving from the application of engineering methods and devices in clinical medicine should be demonstrated. Typically, full length original contributions have a length of 4000 words, thereby taking duly into account figures and tables.
2.Technical Notes and Short Communications: Technical Notes relate to novel technical developments with relevance for clinical medicine. In Short Communications, clinical applications are shortly described. 3.Both Technical Notes and Short Communications typically have a length of 1500 words.
Reviews and Tutorials (upon invitation only): Tutorial and educational articles for persons with a primarily medical background on principles of engineering with particular significance for biomedical applications and vice versa are presented. The Editorial Board is responsible for the selection of topics.
4.Minisymposia (upon invitation only): Under the leadership of a Special Editor, controversial or important issues relating to health care are highlighted and discussed by various authors.
5.Letters to the Editors: Discussions or short statements (not indexed).