Effect of Oxygen Breathing on Flicker Induced Blood Flow Changes in the Optic Nerve Head

The safety and scientific validity of this study is the responsibility of the study sponsor and investigators. Listing a study does not mean it has been evaluated by the U.S. Federal Government. Read our disclaimer for details. Identifier: NCT00406224
Recruitment Status : Completed
First Posted : December 4, 2006
Last Update Posted : December 4, 2006
Information provided by:
Medical University of Vienna

Brief Summary:

Background It has recently been shown that diffuse luminance flicker increases retinal and optic nerve head blood flow. This indicates that a neuro-vascular coupling between neural activity and blood flow exists as described previously for the brain. Although a lot of mediators such as NO, pO2, pCO2, H+ and K+ have been proposed, the mechanism of this coupling is still a matter of controversy. However, it has been shown in an animal experiment, that an increase in blood flow, evoked by diffuse luminance flicker stimulation is paralleled by an decrease in pO2 in the tissue. Thus, in this study we set out to investigate the flicker light induced increase in blood flow under elevated blood pO2.

Study rationale The motive for the investigation of retinal blood flow regulation is to enhance our understanding of the coupling mechanism between increased neural activity and blood flow in the retina in order to gain new insight in the pathophysiology of several eye diseases associated with ocular vascular disorders Study objectives To test the hypothesis whether oxygen breathing influences flicker light induced changes in optic nerve head blood flow

Condition or disease Intervention/treatment Phase
Healthy Drug: breathing 100% oxygen Not Applicable

Study Type : Interventional  (Clinical Trial)
Allocation: Non-Randomized
Intervention Model: Single Group Assignment
Masking: None (Open Label)
Primary Purpose: Diagnostic
Study Start Date : December 2002
Study Completion Date : December 2003

Resource links provided by the National Library of Medicine

MedlinePlus related topics: Oxygen Therapy

Primary Outcome Measures :
  1. Retinal vessel diameters

Information from the National Library of Medicine

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Ages Eligible for Study:   19 Years and older   (Adult, Older Adult)
Sexes Eligible for Study:   Male
Accepts Healthy Volunteers:   Yes

Inclusion Criteria:

  • healthy volunteers

Exclusion Criteria:

  • Regular use of medication, abuse of alcoholic beverages, participation in a clinical trial in the 3 weeks preceding the study
  • Treatment in the previous 3 weeks with any drug
  • Symptoms of a clinically relevant illness in the 3 weeks before the first study day
  • Blood donation during the previous 3 weeks

Information from the National Library of Medicine

To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.

Please refer to this study by its identifier (NCT number): NCT00406224

Sponsors and Collaborators
Medical University of Vienna
Principal Investigator: Gerhard Garhofer, MD Medical University of Vienna Identifier: NCT00406224     History of Changes
Other Study ID Numbers: FliOxyGen
First Posted: December 4, 2006    Key Record Dates
Last Update Posted: December 4, 2006
Last Verified: November 2006