Videokeratograph (VKS) for monitoring corneal curvature during surgery
Autor(a) principal: | |
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Data de Publicação: | 2002 |
Outros Autores: | , , , , , |
Tipo de documento: | Artigo |
Idioma: | eng |
Título da fonte: | Arquivos brasileiros de oftalmologia (Online) |
Texto Completo: | http://old.scielo.br/scielo.php?script=sci_arttext&pid=S0004-27492002000100007 |
Resumo: | Purpose: We have developed an instrument for computerized surgical videokeratography. A corneal central region of approximately 7.00 mm in diameter may be analyzed, providing the surgeon with information of the power and the astigmatism. Methods: The system is based on a fiber optic Placido disc projecting cone, which is attached to the objective lens of a Zeiss compatible surgical microscope. At the beam splitter we installed a monochromatic high resolution camera. A frame grabber is installed on a PC and images are digitized at a 480x640 resolution. Image processing is used for edge detection of rings. Results: Calibrating curves based on 4 spherical surfaces were generated and approximately 3600 points are calculated for each examination. Preliminary measurements on 10 healthy corneas were compared with those of an EyeSys System 2000 Corneal Topographer. Mean deviation was 0.05 for radius of curvature, 0.24 D for the power and 5.0 degrees for the cylinder. Conclusions: This surgical VKS, with some hardware and software improvements, may be used to reduce residual astigmatisms in conventional cataract and keratoplasty. It could also be used to gather preoperative data in corneal topography assisted LASIK. |
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Arquivos brasileiros de oftalmologia (Online) |
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Videokeratograph (VKS) for monitoring corneal curvature during surgeryCorneal topographyKeratometryPlacido discPurpose: We have developed an instrument for computerized surgical videokeratography. A corneal central region of approximately 7.00 mm in diameter may be analyzed, providing the surgeon with information of the power and the astigmatism. Methods: The system is based on a fiber optic Placido disc projecting cone, which is attached to the objective lens of a Zeiss compatible surgical microscope. At the beam splitter we installed a monochromatic high resolution camera. A frame grabber is installed on a PC and images are digitized at a 480x640 resolution. Image processing is used for edge detection of rings. Results: Calibrating curves based on 4 spherical surfaces were generated and approximately 3600 points are calculated for each examination. Preliminary measurements on 10 healthy corneas were compared with those of an EyeSys System 2000 Corneal Topographer. Mean deviation was 0.05 for radius of curvature, 0.24 D for the power and 5.0 degrees for the cylinder. Conclusions: This surgical VKS, with some hardware and software improvements, may be used to reduce residual astigmatisms in conventional cataract and keratoplasty. It could also be used to gather preoperative data in corneal topography assisted LASIK.Conselho Brasileiro de Oftalmologia2002-01-01info:eu-repo/semantics/articleinfo:eu-repo/semantics/publishedVersiontext/htmlhttp://old.scielo.br/scielo.php?script=sci_arttext&pid=S0004-27492002000100007Arquivos Brasileiros de Oftalmologia v.65 n.1 2002reponame:Arquivos brasileiros de oftalmologia (Online)instname:Conselho Brasileiro de Oftalmologia (CBO)instacron:CBO10.1590/S0004-27492002000100007info:eu-repo/semantics/openAccessCarvalho,Luis Alberto Vieira deRomão,Antonio CarlosTonissi,SilvioYasuoka,FátimaCastro,Jarbas C.Schor,PauloChamon,Wallaceeng2002-07-23T00:00:00Zoai:scielo:S0004-27492002000100007Revistahttp://aboonline.org.br/https://old.scielo.br/oai/scielo-oai.phpaboonline@cbo.com.br||abo@cbo.com.br1678-29250004-2749opendoar:2002-07-23T00:00Arquivos brasileiros de oftalmologia (Online) - Conselho Brasileiro de Oftalmologia (CBO)false |
dc.title.none.fl_str_mv |
Videokeratograph (VKS) for monitoring corneal curvature during surgery |
title |
Videokeratograph (VKS) for monitoring corneal curvature during surgery |
spellingShingle |
Videokeratograph (VKS) for monitoring corneal curvature during surgery Carvalho,Luis Alberto Vieira de Corneal topography Keratometry Placido disc |
title_short |
Videokeratograph (VKS) for monitoring corneal curvature during surgery |
title_full |
Videokeratograph (VKS) for monitoring corneal curvature during surgery |
title_fullStr |
Videokeratograph (VKS) for monitoring corneal curvature during surgery |
title_full_unstemmed |
Videokeratograph (VKS) for monitoring corneal curvature during surgery |
title_sort |
Videokeratograph (VKS) for monitoring corneal curvature during surgery |
author |
Carvalho,Luis Alberto Vieira de |
author_facet |
Carvalho,Luis Alberto Vieira de Romão,Antonio Carlos Tonissi,Silvio Yasuoka,Fátima Castro,Jarbas C. Schor,Paulo Chamon,Wallace |
author_role |
author |
author2 |
Romão,Antonio Carlos Tonissi,Silvio Yasuoka,Fátima Castro,Jarbas C. Schor,Paulo Chamon,Wallace |
author2_role |
author author author author author author |
dc.contributor.author.fl_str_mv |
Carvalho,Luis Alberto Vieira de Romão,Antonio Carlos Tonissi,Silvio Yasuoka,Fátima Castro,Jarbas C. Schor,Paulo Chamon,Wallace |
dc.subject.por.fl_str_mv |
Corneal topography Keratometry Placido disc |
topic |
Corneal topography Keratometry Placido disc |
description |
Purpose: We have developed an instrument for computerized surgical videokeratography. A corneal central region of approximately 7.00 mm in diameter may be analyzed, providing the surgeon with information of the power and the astigmatism. Methods: The system is based on a fiber optic Placido disc projecting cone, which is attached to the objective lens of a Zeiss compatible surgical microscope. At the beam splitter we installed a monochromatic high resolution camera. A frame grabber is installed on a PC and images are digitized at a 480x640 resolution. Image processing is used for edge detection of rings. Results: Calibrating curves based on 4 spherical surfaces were generated and approximately 3600 points are calculated for each examination. Preliminary measurements on 10 healthy corneas were compared with those of an EyeSys System 2000 Corneal Topographer. Mean deviation was 0.05 for radius of curvature, 0.24 D for the power and 5.0 degrees for the cylinder. Conclusions: This surgical VKS, with some hardware and software improvements, may be used to reduce residual astigmatisms in conventional cataract and keratoplasty. It could also be used to gather preoperative data in corneal topography assisted LASIK. |
publishDate |
2002 |
dc.date.none.fl_str_mv |
2002-01-01 |
dc.type.driver.fl_str_mv |
info:eu-repo/semantics/article |
dc.type.status.fl_str_mv |
info:eu-repo/semantics/publishedVersion |
format |
article |
status_str |
publishedVersion |
dc.identifier.uri.fl_str_mv |
http://old.scielo.br/scielo.php?script=sci_arttext&pid=S0004-27492002000100007 |
url |
http://old.scielo.br/scielo.php?script=sci_arttext&pid=S0004-27492002000100007 |
dc.language.iso.fl_str_mv |
eng |
language |
eng |
dc.relation.none.fl_str_mv |
10.1590/S0004-27492002000100007 |
dc.rights.driver.fl_str_mv |
info:eu-repo/semantics/openAccess |
eu_rights_str_mv |
openAccess |
dc.format.none.fl_str_mv |
text/html |
dc.publisher.none.fl_str_mv |
Conselho Brasileiro de Oftalmologia |
publisher.none.fl_str_mv |
Conselho Brasileiro de Oftalmologia |
dc.source.none.fl_str_mv |
Arquivos Brasileiros de Oftalmologia v.65 n.1 2002 reponame:Arquivos brasileiros de oftalmologia (Online) instname:Conselho Brasileiro de Oftalmologia (CBO) instacron:CBO |
instname_str |
Conselho Brasileiro de Oftalmologia (CBO) |
instacron_str |
CBO |
institution |
CBO |
reponame_str |
Arquivos brasileiros de oftalmologia (Online) |
collection |
Arquivos brasileiros de oftalmologia (Online) |
repository.name.fl_str_mv |
Arquivos brasileiros de oftalmologia (Online) - Conselho Brasileiro de Oftalmologia (CBO) |
repository.mail.fl_str_mv |
aboonline@cbo.com.br||abo@cbo.com.br |
_version_ |
1754209020776808448 |