RESEARCH ARTICLE
Radiofrequency Heating of the Cornea: An Engineering Review of Electrodes and Applicators
Enrique J Berjano*, 1, Enrique Navarro2, Vicente Ribera2, Javier Gorris2, Jorge L Alió3, 4
Article Information
Identifiers and Pagination:
Year: 2007Volume: 1
First Page: 71
Last Page: 76
Publisher ID: TOBEJ-1-71
DOI: 10.2174/1874120700701010071
Article History:
Received Date: 5/10/2007Revision Received Date: 26/11/2007
Acceptance Date: 27/11/2007
Electronic publication date: 11/12/2007
Collection year: 2007
open-access license: This is an open access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.5/), which permits unrestrictive use, distribution, and reproduction in any medium, provided the original work is properly cited.
Abstract
This paper reviews the different applicators and electrodes employed to create localized heating in the cornea by means of the application of radiofrequency (RF) currents. Thermokeratoplasty (TKP) is probably the best known of these techniques and is based on the principle that heating corneal tissue (particularly the central part of the corneal tissue, i.e. the central stroma) causes collagen to shrink, and hence changes the corneal curvature. Firstly, we point out that TKP techniques are a complex challenge from the engineering point of view, due to the fact that it is necessary to create very localized heating in a precise location (central stroma), within a narrow temperature range (from 58 to 76ºC). Secondly, we describe the different applicator designs (i.e. RF electrodes) proposed and tested to date. This review is planned from a technical point of view, i.e. the technical developments are classified and described taking into consideration technical criteria, such as energy delivery mode (monopolar versus bipolar), thermal conditions (dry versus cooled electrodes), lesion pattern (focal versus circular lesions), and application placement (surface versus intrastromal).