2.50
Hdl Handle:
http://hdl.handle.net/2336/20332
Title:
Automatic retinal oximetry
Authors:
Hardarson, Sveinn Hakon; Harris, Alon; Karlsson, Robert Arnar; Halldorsson, Gisli Hreinn; Kagemann, Larry; Rechtman, Ehud; Zoega, Gunnar Már; Eysteinsson, Thor; Benediktsson, Jon Atli; Thorsteinsson, Adalbjorn; Jensen, Peter Koch; Beach, James; Stefánsson, Einar
Citation:
Invest. Ophthalmol. Vis. Sci. 2006, 47(11):5011-6
Issue Date:
1-Nov-2006
Abstract:
PURPOSE: To measure hemoglobin oxygen saturation (SO(2)) in retinal vessels and to test the reproducibility and sensitivity of an automatic spectrophotometric oximeter. METHODS: Specialized software automatically identifies the retinal blood vessels on fundus images, which are obtained with four different wavelengths of light. The software calculates optical density ratios (ODRs) for each vessel. The reproducibility was evaluated by analyzing five repeated measurements of the same vessels. A linear relationship between SO(2) and ODR was assumed and a linear model derived. After calibration, reproducibility and sensitivity were calculated in terms of SO(2). Systemic hyperoxia (n = 16) was induced in healthy volunteers by changing the O(2) concentration in inhaled air from 21% to 100%. RESULTS: The automatic software enhanced reproducibility, and the mean SD for repeated measurements was 3.7% for arterioles and 5.3% venules, in terms of percentage of SO(2) (five repeats, 10 individuals). The model derived for calibration was SO(2) = 125 - 142 . ODR. The arterial SO(2) measured 96% +/- 9% (mean +/- SD) during normoxia and 101% +/- 8% during hyperoxia (n = 16). The difference between normoxia and hyperoxia was significant (P = 0.0027, paired t-test). Corresponding numbers for venules were 55% +/- 14% and 78% +/- 15% (P < 0.0001). SO(2) is displayed as a pseudocolor map drawn on fundus images. CONCLUSIONS: The retinal oximeter is reliable, easy to use, and sensitive to changes in SO(2) when concentration of O(2) in inhaled air is changed.
Description:
To access publisher full text version of this article. Please click on the hyperlink in Additional Links field
Additional Links:
http://www.iovs.org/cgi/content/abstract/47/11/5011

Full metadata record

DC FieldValue Language
dc.contributor.authorHardarson, Sveinn Hakon-
dc.contributor.authorHarris, Alon-
dc.contributor.authorKarlsson, Robert Arnar-
dc.contributor.authorHalldorsson, Gisli Hreinn-
dc.contributor.authorKagemann, Larry-
dc.contributor.authorRechtman, Ehud-
dc.contributor.authorZoega, Gunnar Már-
dc.contributor.authorEysteinsson, Thor-
dc.contributor.authorBenediktsson, Jon Atli-
dc.contributor.authorThorsteinsson, Adalbjorn-
dc.contributor.authorJensen, Peter Koch-
dc.contributor.authorBeach, James-
dc.contributor.authorStefánsson, Einar-
dc.date.accessioned2008-03-11T14:57:16Z-
dc.date.available2008-03-11T14:57:16Z-
dc.date.issued2006-11-01-
dc.date.submitted2008-03-11-
dc.identifier.citationInvest. Ophthalmol. Vis. Sci. 2006, 47(11):5011-6en
dc.identifier.issn0146-0404-
dc.identifier.pmid17065521-
dc.identifier.doi10.1167/iovs.06-0039-
dc.identifier.urihttp://hdl.handle.net/2336/20332-
dc.descriptionTo access publisher full text version of this article. Please click on the hyperlink in Additional Links fielden
dc.description.abstractPURPOSE: To measure hemoglobin oxygen saturation (SO(2)) in retinal vessels and to test the reproducibility and sensitivity of an automatic spectrophotometric oximeter. METHODS: Specialized software automatically identifies the retinal blood vessels on fundus images, which are obtained with four different wavelengths of light. The software calculates optical density ratios (ODRs) for each vessel. The reproducibility was evaluated by analyzing five repeated measurements of the same vessels. A linear relationship between SO(2) and ODR was assumed and a linear model derived. After calibration, reproducibility and sensitivity were calculated in terms of SO(2). Systemic hyperoxia (n = 16) was induced in healthy volunteers by changing the O(2) concentration in inhaled air from 21% to 100%. RESULTS: The automatic software enhanced reproducibility, and the mean SD for repeated measurements was 3.7% for arterioles and 5.3% venules, in terms of percentage of SO(2) (five repeats, 10 individuals). The model derived for calibration was SO(2) = 125 - 142 . ODR. The arterial SO(2) measured 96% +/- 9% (mean +/- SD) during normoxia and 101% +/- 8% during hyperoxia (n = 16). The difference between normoxia and hyperoxia was significant (P = 0.0027, paired t-test). Corresponding numbers for venules were 55% +/- 14% and 78% +/- 15% (P < 0.0001). SO(2) is displayed as a pseudocolor map drawn on fundus images. CONCLUSIONS: The retinal oximeter is reliable, easy to use, and sensitive to changes in SO(2) when concentration of O(2) in inhaled air is changed.en
dc.language.isoenen
dc.publisherAssociation For Research In Vision And Ophthalmology (Arvo)en
dc.relation.urlhttp://www.iovs.org/cgi/content/abstract/47/11/5011en
dc.subject.meshHumansen
dc.subject.meshHyperoxiaen
dc.subject.meshOximetryen
dc.subject.meshOxygenen
dc.subject.meshOxygen Consumptionen
dc.subject.meshOxyhemoglobinsen
dc.subject.meshReproducibility of Resultsen
dc.subject.meshRetinal Arteryen
dc.subject.meshRetinal Veinen
dc.subject.meshSensitivity and Specificityen
dc.titleAutomatic retinal oximetryen
dc.typeArticleen
dc.contributor.departmentDepartment of Ophthalmology, University of Iceland, National Univbersity Hospital, Reykjavik, Iceland.en
dc.identifier.journalInvestigative ophthalmology & visual scienceen

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