Laser treatment and the mechanism of edema reduction in branch retinal vein occlusion

2.50
Hdl Handle:
http://hdl.handle.net/2336/79174
Title:
Laser treatment and the mechanism of edema reduction in branch retinal vein occlusion
Authors:
Arnarsson, A; Stefansson, E
Citation:
Invest. Ophthalmol. Vis. Sci. 2000, 41(3):877-9
Issue Date:
1-Mar-2000
Abstract:
PURPOSE: To test a hypothesis on the physiological mechanism of the disappearance of macular edema after laser treatment. The hypothesis is based on the effect grid laser treatment has on retinal oxygenation and hemodynamics. It predicts that laser-induced reduction of macular edema is associated with shortening and narrowing of retinal vessels in patients with branch retinal vein occlusion (BRVO). METHODS: The study included 12 subjects, treated with argon laser photocoagulation for BRVO and macular edema. Fundus photographs taken at the time of diagnosis and again after laser treatment, were digitized, and diameter and segment length of retinal vessels was measured using NIH-Image program. RESULTS: Macular edema disappeared or was dramatically reduced in all cases after laser treatment. The diameter of occluded venules constricted to 0.81+/-0.02 (mean +/- SD, P = 0.019) of the prelaser diameter and adjacent arterioles constricted to 0.78+/-0.01 (P = 0.008). The laser treatment also led to shortening of the affected vessels. The final segment length of the occluded venules was 0.95+/-0.17 (P = 0.005) of the length before treatment. The corresponding value for the adjacent arterioles is 0.95+/-0.14 (P = 0.008). Control arterioles and venules in the same fundus did not change in either length or width. CONCLUSIONS: These results do not reject the authors' hypothesis that the disappearance of macular edema in BRVO can be explained by the effect the laser photocoagulation has on retinal oxygenation. Increased oxygenation causes vessel constriction and shortening and lower intravascular pressure, which reduces edema formation according to Starling's law.
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/41/3/877

Full metadata record

DC FieldValue Language
dc.contributor.authorArnarsson, A-
dc.contributor.authorStefansson, E-
dc.date.accessioned2009-08-28T14:44:15Z-
dc.date.available2009-08-28T14:44:15Z-
dc.date.issued2000-03-01-
dc.date.submitted2009-08-28-
dc.identifier.citationInvest. Ophthalmol. Vis. Sci. 2000, 41(3):877-9en
dc.identifier.issn0146-0404-
dc.identifier.pmid10711707-
dc.identifier.urihttp://hdl.handle.net/2336/79174-
dc.descriptionTo access publisher full text version of this article. Please click on the hyperlink in Additional Links fielden
dc.description.abstractPURPOSE: To test a hypothesis on the physiological mechanism of the disappearance of macular edema after laser treatment. The hypothesis is based on the effect grid laser treatment has on retinal oxygenation and hemodynamics. It predicts that laser-induced reduction of macular edema is associated with shortening and narrowing of retinal vessels in patients with branch retinal vein occlusion (BRVO). METHODS: The study included 12 subjects, treated with argon laser photocoagulation for BRVO and macular edema. Fundus photographs taken at the time of diagnosis and again after laser treatment, were digitized, and diameter and segment length of retinal vessels was measured using NIH-Image program. RESULTS: Macular edema disappeared or was dramatically reduced in all cases after laser treatment. The diameter of occluded venules constricted to 0.81+/-0.02 (mean +/- SD, P = 0.019) of the prelaser diameter and adjacent arterioles constricted to 0.78+/-0.01 (P = 0.008). The laser treatment also led to shortening of the affected vessels. The final segment length of the occluded venules was 0.95+/-0.17 (P = 0.005) of the length before treatment. The corresponding value for the adjacent arterioles is 0.95+/-0.14 (P = 0.008). Control arterioles and venules in the same fundus did not change in either length or width. CONCLUSIONS: These results do not reject the authors' hypothesis that the disappearance of macular edema in BRVO can be explained by the effect the laser photocoagulation has on retinal oxygenation. Increased oxygenation causes vessel constriction and shortening and lower intravascular pressure, which reduces edema formation according to Starling's law.en
dc.language.isoenen
dc.publisherAssociation For Research In Vision And Ophthalmology (Arvo)en
dc.relation.urlhttp://www.iovs.org/cgi/content/abstract/41/3/877en
dc.subject.meshAgeden
dc.subject.meshAged, 80 and overen
dc.subject.meshFemaleen
dc.subject.meshFundus Oculien
dc.subject.meshHumansen
dc.subject.meshLaser Coagulationen
dc.subject.meshMacular Edemaen
dc.subject.meshMaleen
dc.subject.meshMiddle Ageden
dc.subject.meshOxygenen
dc.subject.meshRetinal Arteryen
dc.subject.meshRetinal Veinen
dc.subject.meshRetinal Vein Occlusionen
dc.subject.meshVisual Acuityen
dc.titleLaser treatment and the mechanism of edema reduction in branch retinal vein occlusionen
dc.typeArticleen
dc.contributor.departmentDepartment of Ophthalmology, University of Iceland, Reykjavik.en
dc.identifier.journalInvestigative ophthalmology & visual scienceen

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