AzTrials
AzTrials

HealthyNCT02531399

Measurement of Total Retinal Blood Flow During Flicker Stimulation in Healthy Subjects

A study testing FDOCT, LDV and DVA in people with Healthy, run by Medical University of Vienna at 1 site in Austria.

Completed

Finished. The study has ended and is not enrolling. Results may be posted on the official record.

Official record
Search all trials

Trial summary

Neurovascular coupling or functional hyperemia is defined as an essential physiologic mechanism in the brain, which is necessary for the local adaption of blood flow to altered metabolic demands of the tissue. It has been shown that also in the eye, blood flow is considerably coupled to retinal neural activity. Read more about this study

Who is it for?
Ages 18 to 45 yearsHealthy volunteers can take part
Conditions the study is for
Healthy
What is being tested?
FDOCT, LDV and DVA
Type of treatment
Medical device
Could I receive a placebo?
No, everyone receives an active treatment
How many people
20 participants
Where
1 siteAustria
Study dates
Oct 2015to Sep 2017
Phase
Interventional
Are there results?
None posted in the registry

Key requirements

Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.

  • Ages 18 to 45 years
  • All sexes
  • Healthy volunteers accepted
  • Adult

Who may be able to join

  • Informed consent for participation
  • Men and women aged between 18 and 45 years
  • Non-smokers
  • Normal findings in the medical history and physical examination unless the investigator considers an abnormality to be clinically irrelevant
  • Systolic blood pressure < 140 mmHg, diastolic blood pressure < 90 mmHg
  • Normal ophthalmic findings, ametropia less than 3 diopters

Who cannot join

  • History or presence of ocular disease
  • Ametropy ≥ 3 dpt
  • Treatment with any drug in the 3 weeks preceding the first study day
  • Symptoms of a clinically relevant illness in the 3 weeks before the first study day
  • Participation in a clinical trial in the 3 weeks preceding the first study day
  • Blood donation during the 3 weeks preceding the first study day
Show all 9Show fewer
  • History of family history of epilepsy
  • Abuse of alcoholic beverages
  • Pregnancy

Trial locations and contacts

1 site in 1 country.

Austria1 site
  • Department of Clinical Pharmacology, Medical University of Vienna, Austria

    Vienna, 1090

Other trials in Austria

About this study

Neurovascular coupling or functional hyperemia is defined as an essential physiologic mechanism in the brain, which is necessary for the local adaption of blood flow to altered metabolic demands of the tissue. It has been shown that also in the eye, blood flow is considerably coupled to retinal neural activity. The current concept of functional hyperemia is that visual stimulation, as flicker light, effectuates increasing neural activity in the retina, which elevates the metabolic needs of the retinal tissue for oxygen and glucose and consequently induces dilatation and augmented blood flow in the retinal vasculature. In several studies, stimulation with flicker light has been shown to induce an increase of blood flow in major retinal arteries and veins as well as an increase of optic nerve head blood flow. Up until now, flicker induced changes in blood flow were measured solely in the major retinal arteries and veins with systems such as the commercially available dynamic vessel analyzer (DVA) by Imedos and with laser Doppler velocimetry (LDV).

In the present study, the investigators propose to measure the response of total retinal blood flow to diffuse luminance flicker stimulation with bi-directional Fourier Domain Doppler Optical Coherence Tomography (FDOCT) as well as with Laser Speckle Flowgraphy (LSFG) in healthy subjects by assessing vessel diameter, blood velocity and blood flow of all retinal vessels. For comparative reasons, the investigators will furthermore assess the blood flow of major retinal arteries and veins with the dynamic vessel analyzer (DVA) and laser Doppler velocimetry (LDV).

Conditions
Healthy
Being tested
FDOCT, LDV, DVA, LSFG
Keywords
flicker induced changes, total volumetric retinal blood flow

What participants receive

What participants receive. In a randomised study each person is assigned to one group by chance.

  • FDOCTDevice

    Also called Fourier Domain Color Doppler Optical Coherence Tomography

    Measurement of retinal blood velocities

  • LDVDevice

    Also called Laser Doppler Velocimetry

    Measurement of retinal blood velocities

  • DVADevice

    Also called Dynamic Vessel Analyzer

    Measurement of retinal vessel diameters

  • LSFGDevice

    Also called Laser Speckle Flowgraphy

    Imaging of retinal blood flow

Study groups in NCT02531399
Study groupRoleWhat they receive
Healthy SubjectsExperimental20 healthy female and male volunteers, age 18-45 years, non-smokers. Measurements with FDOCT, DVA, LDV and LSFG will be done in all healthy subjects.
Receives: Device: FDOCT; Device: LDV; Device: DVA; Device: LSFG

What is being measured

The primary outcome is the main question the study is designed to answer.

  1. Flicker induced changes in total retinal blood flow (FDOCT)

    Measured: 1 day

Secondary outcomes (4)
  1. Red blood cell velocity (LDV)

    Measured: 1 day

  2. Retinal vessel diameters (DVA)

    Measured: 1 day

  3. Retinal oxygen saturation (DVA)

    Measured: 1 day

  4. Relative Flow Volume (LSFG)

    Measured: 1 day

Timeline

From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.

  1. First posted24 Aug 2015 (estimated)
  2. Study startOct 2015
  3. Primary completionAug 2017
  4. Study completionSep 2017

Resources

More details

For doctors and researchers: how the study is designed, who runs it, and its registry IDs.

Study design
Study type
Interventional
Phase
Phase N/A
Primary purpose
Basic science
Allocation
Not applicable
Intervention model
Single group
Masking
None (open label)
Enrolment
20 participants (actual)
IDs, dates and publications
ClinicalTrials.gov ID
NCT02531399
Sponsor's protocol ID
OPHT-250315
Status last verified
Sep 2017
First submitted
20 Aug 2015
Last updated
6 Sep 2017
Results posted
No

Publications

  • Fondi K, Aschinger GC, Bata AM, Wozniak PA, Liao L, Seidel G, Doblhoff-Dier V, Schmidl D, Garhofer G, Werkmeister RM, Schmetterer L. Measurement of Retinal Vascular Caliber From Optical Coherence Tomography Phase Images. Invest Ophthalmol Vis Sci. 2016 Jul 1;57(9):OCT121-9. doi: 10.1167/iovs.15-18476.

    PubMed 27409462

Questions about this trial

What is this clinical trial studying?

A study testing FDOCT, LDV and DVA in people with Healthy, run by Medical University of Vienna at 1 site in Austria.

The full registered description is in the About this study section and the official record.

Who may be eligible to take part?

The sponsor lists 6 inclusion and 9 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.

Is this clinical trial currently recruiting?

The record says: finished, as of the sponsor's last update on 6 Sep 2017. Status can change between updates, so confirm with the study contact before making plans.

Where is the study taking place?

The record lists 1 site in Austria. Whether a site is taking part right now should be confirmed with that site. See every site.

What are the possible benefits and risks?

They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.

Are results available for this study?

The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.

How can a doctor refer a patient or contact the research team?

The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.

What does the primary outcome measure?

Flicker induced changes in total retinal blood flow (FDOCT) (time frame: 1 day). It is what the study was designed to measure, not a finding.

Where can I read the original study information?

On the ClinicalTrials.gov record for NCT02531399, which also lists 1 linked publication.

Does a listing mean the treatment is approved or proven to work?

No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.

How often is this information updated?

AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 6 Sep 2017.

Free account

Log in to keep searching

You’ve used your 3 free searches. AzTrials is free: log in or create a free account to keep searching clinical trials and save the ones you want to follow.

Create a free accountLog in