The Effect of A2A Adrenoceptor Stimulation on the Diameter of Retinal Arterioles During Hypoxia in Vivo
1 other identifier
interventional
20
1 country
1
Brief Summary
The purpose is to investigate how the adenosine affects the diameter regulation of retinal arterioles during changes in oxygen tension. A deeper understanding of the mechanisms involved in diameter regulation of retinal arterioles during changes in oxygen tension can be used to obtain a more detailed understanding of diseases where changes in the diameter regulation of retinal vessels are involved in the disease pathogenesis and possibly point to new therapeutic options for patients with retinal vascular disease, such as diabetic retinopathy and retinal vein thrombosis. Preliminary, a routine ophthalmological evaluation, measurement of blood pressure, and electrocardiogram will be preformed to insure that only healthy test persons are included in the study. The test persons will be randomly allocated to two groups, one group in which protocol 1 is followed by protocol 2, and the other group with the two protocols performed in the reverse order. Protocol 1: Using the DVA, a video recording will capture the diameter of retinal vessels and the changes occurring during stimulation with flickering light. The recording lasts 4.5 minutes and is preformed before and after intravenous injection of adenosine. Protocol 2: The procedures are similar to those of protocol 1 but are performed during breathing of a gas mixture with a reduced oxygen tension to 12,5 %, which results in a reduced oxygen saturation in the blood to 85-90 %.
Trial Health
Trial Health Score
Automated assessment based on enrollment pace, timeline, and geographic reach
participants targeted
Target at below P25 for phase_2
Started Mar 2017
Shorter than P25 for phase_2
1 active site
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
First Submitted
Initial submission to the registry
March 10, 2017
CompletedStudy Start
First participant enrolled
March 22, 2017
CompletedFirst Posted
Study publicly available on registry
March 24, 2017
CompletedPrimary Completion
Last participant's last visit for primary outcome
November 1, 2017
CompletedStudy Completion
Last participant's last visit for all outcomes
November 1, 2017
CompletedMarch 28, 2017
March 1, 2017
7 months
March 10, 2017
March 24, 2017
Conditions
Keywords
Outcome Measures
Primary Outcomes (1)
Diameter responses of retinal arterioles
The main outcome variable of the DVA is the width measurement of the selected vessel(s), expressed in units of measurement (UM). In a normal Gullstrand eye, 1 UM is equivalent to 1 µm. For the stimulation with flicker light, the outcome is defined as the percent change from baseline.
11 minutes
Secondary Outcomes (3)
Blood pressure
The blood pressure is measured during the last 40 seconds in each phase using an oscillometric technique on the left arm.
Systemic arterial saturation
The systemic arterial saturation is registered at the beginning and half way through each examination phase and during the 2 min break where the drug Regadenoson is injected.
Intraocular pressure
The intraocular pressure is measured before and after the drug administration (time point 280 and 350 sec) and after the second DVA examination is terminated (time point 670 sec).
Study Arms (1)
Healthy person
EXPERIMENTALThe purpose is to investigate the effect of A2A adrenoceptor stimulation using the drug regadenoson (Rapiscan) on the diameter of retinal arterioles during hypoxia in vivo.
Interventions
The purpose is to test the effect of A2A adrenoceptor stimulation on the diameter of retinal arterioles during hypoxia in vivo
The purpose is to test the effect of A2A adrenoceptor stimulation on the diameter of retinal arterioles during hypoxia in vivo
Eligibility Criteria
You may qualify if:
- Age 20-35
- Healthy, both current and prior
- Normal echocardiogram
- Signed and informed consent
You may not qualify if:
- Former or current cardiovascular disease or high blood pressure
- Lung diseases incl. asthma or chronic obstructive pulmonary disease (COPD)
- Known eye disease or previously treated for an eye disease, particularly glaucoma and cataracts
- People taking medication, except birth control pills
- Persons who have or who have had epilepsy
- Pregnant or breast-feeding women
- Allergies to the constituent substance of the medication used in the study
Contact the study team to confirm eligibility.
Sponsors & Collaborators
Study Sites (1)
Department of Ophthalmology, Aarhus University Hospital
Aarhus, 8000, Denmark
MeSH Terms
Conditions
Interventions
Condition Hierarchy (Ancestors)
Study Officials
- STUDY CHAIR
Toke Bek, Chair
Main supervisor
Central Study Contacts
Study Design
- Study Type
- interventional
- Phase
- phase 2
- Allocation
- NA
- Masking
- NONE
- Purpose
- BASIC SCIENCE
- Intervention Model
- SINGLE GROUP
- Sponsor Type
- OTHER
- Responsible Party
- SPONSOR
Study Record Dates
First Submitted
March 10, 2017
First Posted
March 24, 2017
Study Start
March 22, 2017
Primary Completion
November 1, 2017
Study Completion
November 1, 2017
Last Updated
March 28, 2017
Record last verified: 2017-03
Data Sharing
- IPD Sharing
- Will share
The project results will be published in recognized international journals. Both positive, negative and inconclusive results will be published.