NCT00406224

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

Trial Health

100
On Track

Trial Health Score

Automated assessment based on enrollment pace, timeline, and geographic reach

Timeline
Completed

Started Dec 2002

Typical duration for not_applicable healthy

Status
completed

Health score is calculated from publicly available data and should be used for screening purposes only.

Trial Relationships

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Study Timeline

Key milestones and dates

Study Start

First participant enrolled

December 1, 2002

Completed
1 year until next milestone

Study Completion

Last participant's last visit for all outcomes

December 1, 2003

Completed
3 years until next milestone

First Submitted

Initial submission to the registry

November 30, 2006

Completed
4 days until next milestone

First Posted

Study publicly available on registry

December 4, 2006

Completed
Last Updated

December 4, 2006

Status Verified

November 1, 2006

First QC Date

November 30, 2006

Last Update Submit

December 1, 2006

Conditions

Healthy

Outcome Measures

Primary Outcomes (1)

  • Retinal vessel diameters

Interventions

breathing 100% oxygenDRUG

Eligibility Criteria

Age19 Years+
Sexmale
Healthy VolunteersYes
Age GroupsAdult (18-64), Older Adult (65+)

You may qualify if:

  • healthy volunteers

You may not qualify if:

  • 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

Contact the study team to confirm eligibility.

Sponsors & Collaborators

MeSH Terms

Interventions

RespirationOxygen

Intervention Hierarchy (Ancestors)

Respiratory Physiological PhenomenaCirculatory and Respiratory Physiological PhenomenaChalcogensElementsInorganic ChemicalsGases

Study Officials

  • Gerhard Garhofer, MD

    Medical University of Vienna

    PRINCIPAL INVESTIGATOR

Study Design

Study Type
interventional
Phase
not applicable
Allocation
NON RANDOMIZED
Masking
NONE
Purpose
DIAGNOSTIC
Intervention Model
SINGLE GROUP
Sponsor Type
OTHER

Study Record Dates

First Submitted

November 30, 2006

First Posted

December 4, 2006

Study Start

December 1, 2002

Study Completion

December 1, 2003

Last Updated

December 4, 2006

Record last verified: 2006-11