Healthy
Conditions
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
Interventions
DRUGbreathing 100% oxygen
Sponsors
Medical University of Vienna
Study design
Allocation
NON_RANDOMIZED
Intervention model
SINGLE_GROUP
Primary purpose
DIAGNOSTIC
Masking
NONE
Eligibility
Sex/Gender
MALE
Age
19 Years to No maximum
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
Design outcomes
Primary
| Measure | Time frame |
|---|---|
| Retinal vessel diameters | — |
Outcome results
None listed