Oxygen diffusion and edema with modern scleral rigid gas permeable contact lenses
Main Author: | |
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Publication Date: | 2014 |
Other Authors: | , , , , |
Format: | Article |
Language: | eng |
Source: | Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos) |
Download full: | http://hdl.handle.net/1822/37101 |
Summary: | PURPOSE. We defined the theoretical oxygen tension behind modern scleral contact lenses (CLs) made of different rigid gas permeable (RGP) materials, assuming different thickness of the tear layer behind the lens. A second goal was to show clinically the effect of the postlens tear film on corneal swelling. METHODS. We simulated the partial pressure of oxygen across the cornea behind scleral CLs made of different lens materials (oxygen permeability Dk, 75–200 barrer) and different thickness (Tav, 100–300 lm). Postlens tear film thicknesses (Tpost-tear) ranging from 150 to 350 lm were considered. Eight healthy subjects were fitted randomly with a scleral lens with a thin and a thick postlens tear layer in two different sessions for a period of 3 hours under open-eye conditions. RESULTS. The CLs with less than 125 barrer of Dk and a thickness over 200 lm depleted the oxygen availability at the lens–cornea interface below 55 mm Hg for a postlens tear film of 150 lm. For a postlens tear film thickness of 350 lm, no combination of material or lens thickness will meet the criteria of 55 mm Hg. Our clinical measures of corneal edema showed that this was significantly higher (P < 0.001, Wilcoxon signed ranks test) with the thicker compared to the thinner Tpost-tear (mean 6 SD, 1.66 6 1.12 vs. 4.27 6 1.19%). CONCLUSIONS. Scleral RGP CLs must be comprised of at least 125 barrer of oxygen permeability and up to 200 lm thick to avoid hypoxic effects even under open eye conditions. Postlens tear film layer should be below 150 lm to avoid clinically significant edema |
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Oxygen diffusion and edema with modern scleral rigid gas permeable contact lensesScleral lensesOxygen transmissibilityCorneal edemaTear filmBoundary layersScience & TechnologyPURPOSE. We defined the theoretical oxygen tension behind modern scleral contact lenses (CLs) made of different rigid gas permeable (RGP) materials, assuming different thickness of the tear layer behind the lens. A second goal was to show clinically the effect of the postlens tear film on corneal swelling. METHODS. We simulated the partial pressure of oxygen across the cornea behind scleral CLs made of different lens materials (oxygen permeability Dk, 75–200 barrer) and different thickness (Tav, 100–300 lm). Postlens tear film thicknesses (Tpost-tear) ranging from 150 to 350 lm were considered. Eight healthy subjects were fitted randomly with a scleral lens with a thin and a thick postlens tear layer in two different sessions for a period of 3 hours under open-eye conditions. RESULTS. The CLs with less than 125 barrer of Dk and a thickness over 200 lm depleted the oxygen availability at the lens–cornea interface below 55 mm Hg for a postlens tear film of 150 lm. For a postlens tear film thickness of 350 lm, no combination of material or lens thickness will meet the criteria of 55 mm Hg. Our clinical measures of corneal edema showed that this was significantly higher (P < 0.001, Wilcoxon signed ranks test) with the thicker compared to the thinner Tpost-tear (mean 6 SD, 1.66 6 1.12 vs. 4.27 6 1.19%). CONCLUSIONS. Scleral RGP CLs must be comprised of at least 125 barrer of oxygen permeability and up to 200 lm thick to avoid hypoxic effects even under open eye conditions. Postlens tear film layer should be below 150 lm to avoid clinically significant edemaSupported by the Ministerio de Educacion y Ciencia (MEC) through Project ENE2011-24761, and by FEDER through the COMPETE Program and by the Portuguese Foundation for Science and Technology (FCT) in the framework of the Strategic Project PEST-C/FIS/UI607/2011. The authors alone are responsible for the content and writing of the paper.Association for Research in Vision and Ophthalmology (ARVO)Universidade do MinhoCompañ-Moreno, V.Oliveira, CristinaAguilella-Arzo, MarcelMollá, SergioMatos, Sofia Cláudia Peixoto deGonzález-Méijome, José Manuel20142014-01-01T00:00:00Zinfo:eu-repo/semantics/publishedVersioninfo:eu-repo/semantics/articleapplication/pdfhttp://hdl.handle.net/1822/37101engCompañ, Vicente; Oliveira, Cristina; Aguilella-Arzo, Marcel; Mollá, Sergio; Peixoto-de-Matos, Sofia C; González-Méijome, José M.Oxygen Diffusion and Edema With Modern Scleral Rigid Gas Permeable Contact Lenses, Investigative Opthalmology & Visual Science, 55, 10, 6421-6421, 2014.1552-578310.1167/iovs.14-1403825190661info:eu-repo/semantics/openAccessreponame:Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos)instname:Agência para a Sociedade do Conhecimento (UMIC) - FCT - Sociedade da Informaçãoinstacron:RCAAP2023-07-21T12:08:23Zoai:repositorium.sdum.uminho.pt:1822/37101Portal AgregadorONGhttps://www.rcaap.pt/oai/openaireopendoar:71602024-03-19T18:59:38.004274Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos) - Agência para a Sociedade do Conhecimento (UMIC) - FCT - Sociedade da Informaçãofalse |
dc.title.none.fl_str_mv |
Oxygen diffusion and edema with modern scleral rigid gas permeable contact lenses |
title |
Oxygen diffusion and edema with modern scleral rigid gas permeable contact lenses |
spellingShingle |
Oxygen diffusion and edema with modern scleral rigid gas permeable contact lenses Compañ-Moreno, V. Scleral lenses Oxygen transmissibility Corneal edema Tear film Boundary layers Science & Technology |
title_short |
Oxygen diffusion and edema with modern scleral rigid gas permeable contact lenses |
title_full |
Oxygen diffusion and edema with modern scleral rigid gas permeable contact lenses |
title_fullStr |
Oxygen diffusion and edema with modern scleral rigid gas permeable contact lenses |
title_full_unstemmed |
Oxygen diffusion and edema with modern scleral rigid gas permeable contact lenses |
title_sort |
Oxygen diffusion and edema with modern scleral rigid gas permeable contact lenses |
author |
Compañ-Moreno, V. |
author_facet |
Compañ-Moreno, V. Oliveira, Cristina Aguilella-Arzo, Marcel Mollá, Sergio Matos, Sofia Cláudia Peixoto de González-Méijome, José Manuel |
author_role |
author |
author2 |
Oliveira, Cristina Aguilella-Arzo, Marcel Mollá, Sergio Matos, Sofia Cláudia Peixoto de González-Méijome, José Manuel |
author2_role |
author author author author author |
dc.contributor.none.fl_str_mv |
Universidade do Minho |
dc.contributor.author.fl_str_mv |
Compañ-Moreno, V. Oliveira, Cristina Aguilella-Arzo, Marcel Mollá, Sergio Matos, Sofia Cláudia Peixoto de González-Méijome, José Manuel |
dc.subject.por.fl_str_mv |
Scleral lenses Oxygen transmissibility Corneal edema Tear film Boundary layers Science & Technology |
topic |
Scleral lenses Oxygen transmissibility Corneal edema Tear film Boundary layers Science & Technology |
description |
PURPOSE. We defined the theoretical oxygen tension behind modern scleral contact lenses (CLs) made of different rigid gas permeable (RGP) materials, assuming different thickness of the tear layer behind the lens. A second goal was to show clinically the effect of the postlens tear film on corneal swelling. METHODS. We simulated the partial pressure of oxygen across the cornea behind scleral CLs made of different lens materials (oxygen permeability Dk, 75–200 barrer) and different thickness (Tav, 100–300 lm). Postlens tear film thicknesses (Tpost-tear) ranging from 150 to 350 lm were considered. Eight healthy subjects were fitted randomly with a scleral lens with a thin and a thick postlens tear layer in two different sessions for a period of 3 hours under open-eye conditions. RESULTS. The CLs with less than 125 barrer of Dk and a thickness over 200 lm depleted the oxygen availability at the lens–cornea interface below 55 mm Hg for a postlens tear film of 150 lm. For a postlens tear film thickness of 350 lm, no combination of material or lens thickness will meet the criteria of 55 mm Hg. Our clinical measures of corneal edema showed that this was significantly higher (P < 0.001, Wilcoxon signed ranks test) with the thicker compared to the thinner Tpost-tear (mean 6 SD, 1.66 6 1.12 vs. 4.27 6 1.19%). CONCLUSIONS. Scleral RGP CLs must be comprised of at least 125 barrer of oxygen permeability and up to 200 lm thick to avoid hypoxic effects even under open eye conditions. Postlens tear film layer should be below 150 lm to avoid clinically significant edema |
publishDate |
2014 |
dc.date.none.fl_str_mv |
2014 2014-01-01T00:00:00Z |
dc.type.status.fl_str_mv |
info:eu-repo/semantics/publishedVersion |
dc.type.driver.fl_str_mv |
info:eu-repo/semantics/article |
format |
article |
status_str |
publishedVersion |
dc.identifier.uri.fl_str_mv |
http://hdl.handle.net/1822/37101 |
url |
http://hdl.handle.net/1822/37101 |
dc.language.iso.fl_str_mv |
eng |
language |
eng |
dc.relation.none.fl_str_mv |
Compañ, Vicente; Oliveira, Cristina; Aguilella-Arzo, Marcel; Mollá, Sergio; Peixoto-de-Matos, Sofia C; González-Méijome, José M.Oxygen Diffusion and Edema With Modern Scleral Rigid Gas Permeable Contact Lenses, Investigative Opthalmology & Visual Science, 55, 10, 6421-6421, 2014. 1552-5783 10.1167/iovs.14-14038 25190661 |
dc.rights.driver.fl_str_mv |
info:eu-repo/semantics/openAccess |
eu_rights_str_mv |
openAccess |
dc.format.none.fl_str_mv |
application/pdf |
dc.publisher.none.fl_str_mv |
Association for Research in Vision and Ophthalmology (ARVO) |
publisher.none.fl_str_mv |
Association for Research in Vision and Ophthalmology (ARVO) |
dc.source.none.fl_str_mv |
reponame:Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos) instname:Agência para a Sociedade do Conhecimento (UMIC) - FCT - Sociedade da Informação instacron:RCAAP |
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Agência para a Sociedade do Conhecimento (UMIC) - FCT - Sociedade da Informação |
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Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos) |
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Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos) |
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Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos) - Agência para a Sociedade do Conhecimento (UMIC) - FCT - Sociedade da Informação |
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