2.50
Hdl Handle:
http://hdl.handle.net/2336/75773
Title:
Oxygen saturation in human retinal vessels is higher in dark than in light
Authors:
Hardarson, Sveinn Hakon; Basit, Samy; Jonsdottir, Thora Elisabet; Eysteinsson, Thor; Halldorsson, Gisli Hreinn; Karlsson, Robert Arnar; Beach, James Melvin; Benediktsson, Jon Atli; Stefansson, Einar
Citation:
Invest. Ophthalmol. Vis. Sci. 2009, 50(5):2308-11
Issue Date:
1-May-2009
Abstract:
PURPOSE: Animal studies have indicated that retinal oxygen consumption is greater in dark than light. In this study, oxygen saturation is measured in retinal vessels of healthy humans during dark and light. METHODS: The oximeter consists of a fundus camera, a beam splitter, a digital camera and software, which calculates hemoglobin oxygen saturation in the retinal vessels. In the first experiment, 18 healthy individuals underwent oximetry measurements after 30 minutes in the dark, followed by alternating 5-minute periods of white light (80 cd/m(2)) and dark. In the second experiment, 23 volunteers underwent oximetry measurements after 30 minutes in the dark, followed by light at 1, 10, and 100 cd/m(2). Three subjects were excluded from analysis in the first experiment and four in the second experiment because of poor image quality. RESULTS: In the first experiment, the arteriolar saturation decreased from 92% +/- 4% (n = 15; mean +/- SD) after 30 minutes in the dark to 89% +/- 5% after 5 minutes in the light (P = 0.008). Corresponding numbers for venules are 60% +/- 5% in the dark and 55% +/- 10% (P = 0.020) in the light. In the second experiment, the arteriolar saturation was 92% +/- 4% in the dark and 88% +/- 7% in 100 cd/m(2) light (n = 19, P = 0.012). The corresponding values for venules were 59% +/- 9% in the dark and 55% +/- 10% in 100 cd/m(2) light (P = 0.065). CONCLUSIONS: Oxygen saturation in retinal blood vessels is higher in dark than in 80 or 100 cd/m(2) light in human retinal arterioles and venules. The authors propose that this is a consequence of increased oxygen demand in the outer retina in the dark.
Description:
To access publisher full text version of this article. Please click on the hyperlink in Additional Links field
Additional Links:
http://dx.doi.org/10.1167/iovs.08-2576

Full metadata record

DC FieldValue Language
dc.contributor.authorHardarson, Sveinn Hakon-
dc.contributor.authorBasit, Samy-
dc.contributor.authorJonsdottir, Thora Elisabet-
dc.contributor.authorEysteinsson, Thor-
dc.contributor.authorHalldorsson, Gisli Hreinn-
dc.contributor.authorKarlsson, Robert Arnar-
dc.contributor.authorBeach, James Melvin-
dc.contributor.authorBenediktsson, Jon Atli-
dc.contributor.authorStefansson, Einar-
dc.date.accessioned2009-07-28T14:46:18Z-
dc.date.available2009-07-28T14:46:18Z-
dc.date.issued2009-05-01-
dc.date.submitted2009-07-01-
dc.identifier.citationInvest. Ophthalmol. Vis. Sci. 2009, 50(5):2308-11en
dc.identifier.issn1552-5783-
dc.identifier.pmid19117923-
dc.identifier.doi10.1167/iovs.08-2576-
dc.identifier.urihttp://hdl.handle.net/2336/75773-
dc.descriptionTo access publisher full text version of this article. Please click on the hyperlink in Additional Links fielden
dc.description.abstractPURPOSE: Animal studies have indicated that retinal oxygen consumption is greater in dark than light. In this study, oxygen saturation is measured in retinal vessels of healthy humans during dark and light. METHODS: The oximeter consists of a fundus camera, a beam splitter, a digital camera and software, which calculates hemoglobin oxygen saturation in the retinal vessels. In the first experiment, 18 healthy individuals underwent oximetry measurements after 30 minutes in the dark, followed by alternating 5-minute periods of white light (80 cd/m(2)) and dark. In the second experiment, 23 volunteers underwent oximetry measurements after 30 minutes in the dark, followed by light at 1, 10, and 100 cd/m(2). Three subjects were excluded from analysis in the first experiment and four in the second experiment because of poor image quality. RESULTS: In the first experiment, the arteriolar saturation decreased from 92% +/- 4% (n = 15; mean +/- SD) after 30 minutes in the dark to 89% +/- 5% after 5 minutes in the light (P = 0.008). Corresponding numbers for venules are 60% +/- 5% in the dark and 55% +/- 10% (P = 0.020) in the light. In the second experiment, the arteriolar saturation was 92% +/- 4% in the dark and 88% +/- 7% in 100 cd/m(2) light (n = 19, P = 0.012). The corresponding values for venules were 59% +/- 9% in the dark and 55% +/- 10% in 100 cd/m(2) light (P = 0.065). CONCLUSIONS: Oxygen saturation in retinal blood vessels is higher in dark than in 80 or 100 cd/m(2) light in human retinal arterioles and venules. The authors propose that this is a consequence of increased oxygen demand in the outer retina in the dark.en
dc.language.isoenen
dc.publisherAssociation For Research In Vision And Ophthalmology (Arvo)en
dc.relation.urlhttp://dx.doi.org/10.1167/iovs.08-2576en
dc.subject.meshAdulten
dc.subject.meshDark Adaptationen
dc.subject.meshFemaleen
dc.subject.meshHumansen
dc.subject.meshLighten
dc.subject.meshMaleen
dc.subject.meshMiddle Ageden
dc.subject.meshOximetryen
dc.subject.meshOxygenen
dc.subject.meshOxygen Consumptionen
dc.subject.meshRegional Blood Flowen
dc.subject.meshRetinal Vesselsen
dc.titleOxygen saturation in human retinal vessels is higher in dark than in lighten
dc.typeArticleen
dc.contributor.departmentDepartment of Ophthalmology, University of Iceland/Landspítali University Hospital, Reykjavik, Iceland.en
dc.identifier.journalInvestigative ophthalmology & visual scienceen

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