English   español  
Please use this identifier to cite or link to this item: http://hdl.handle.net/10261/8692
logo share SHARE   Add this article to your Mendeley library MendeleyBASE
Visualizar otros formatos: MARC | Dublin Core | RDF | ORE | MODS | METS | DIDL
Exportar a otros formatos:


Increase in corneal asphericity after standard laser in situ keratomileusis for myopia is not inherent to the Munnerlyn algorithm

AuthorsMarcos, Susana ; Cano, Daniel; Barbero, Sergio
KeywordsOptical aberrations
Refractive surgery
Laser in situ keratomileusis (LASIK)
Corneal asphericity
Ablation algorithms
Munnerlyn algorithm
Issue DateSep-2003
PublisherInternational Society of Refractive Surgery
Slack Incorporated
CitationJournal of Refractive Surgery 19(5): 592-596 (2003)
Abstract[Purpose] Standard refractive surgery for myopia induces a shift in corneal asphericity toward positive values, resulting in an increase of spherical aberration. Analytical studies of changes in theoretical corneal shape after application of standard algorithms have yielded controversial conclusions. This study tries to resolve this controversy and discusses causes of optical degradation after refractive surgery.
[Methods] Computationally, we subtracted from real preoperative corneas the ablation depth given by the Munnerlyn equation and the parabolic approximation of the Munnerlyn equation. We compared the predicted postoperative corneal asphericity (and corneal spherical aberration) with real postoperative corneal asphericities of the same eyes, after laser in situ keratomileusis (LASIK).
[Results] Corneal asphericity increased after LASIK in real eyes, with an increase proportional to the amount of correction. This increase was not predicted by the computational application of the Munnerlyn algorithm, which predicted a slight decrease of corneal asphericity. The parabolic approximation of the Munnerlyn algorithm produced an increase in corneal asphericity that correlated with the amount of correction, but was less than the clinical findings.
[Conclusion] Potential causes for increased asphericity (radial changes in laser efficiency, epithelial healing, and biomechanical response) are discussed. These conclusions are important for the design of optimized and customized ablation algorithms, since the theoretical performance of a given ablation algorithm (ie, Munnerlyn algorithm) can differ drastically from real outcomes.
Description5 pages, 2 figures.-- PMID: 14518750 [PubMed].-- Presented at the Fourth International Congress on Wavefront Sensing and Aberration-free Refractive Correction, February 14-16, 2003, San Francisco, CA.
Publisher version (URL)http://www.journalofrefractivesurgery.com/showAbst.asp?thing=6205
Appears in Collections:(CFMAC-IO) Artículos
Files in This Item:
File Description SizeFormat 
Increase_corneal_asphericity.pdf749,91 kBAdobe PDFThumbnail
Show full item record
Review this work

WARNING: Items in Digital.CSIC are protected by copyright, with all rights reserved, unless otherwise indicated.