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

NCT02531399 | Completed

• 1 other identifier: OPHT-250315
• Study Type: interventional
• Target: 20
• Locations: 1 country
• Sites: 1

Brief 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. 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

Keywords

flicker induced changes; total volumetric retinal blood flow

Outcome Measures

Primary Outcomes (1)

• Flicker induced changes in total retinal blood flow (FDOCT)

  1 day

Secondary Outcomes (4)

• Red blood cell velocity (LDV)

  1 day

• Retinal vessel diameters (DVA)

  1 day

• Retinal oxygen saturation (DVA)

  1 day

• Relative Flow Volume (LSFG)

  1 day

Study Arms (1)

Healthy Subjects

EXPERIMENTAL

20 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.

Device: FDOCT; Device: LDV; Device: DVA; Device: LSFG

Interventions

FDOCT DEVICE

Measurement of retinal blood velocities

Also known as: Fourier Domain Color Doppler Optical Coherence Tomography

Healthy Subjects

LDV DEVICE

Measurement of retinal blood velocities

Also known as: Laser Doppler Velocimetry

Healthy Subjects

DVA DEVICE

Measurement of retinal vessel diameters

Also known as: Dynamic Vessel Analyzer

Healthy Subjects

LSFG DEVICE

Imaging of retinal blood flow

Also known as: Laser Speckle Flowgraphy

Healthy Subjects

Eligibility Criteria

• Age: 18 Years - 45 Years
• Sex: all
• Healthy Volunteers: Yes
• Age Groups: Adult (18-64)

You may qualify if:

• 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

You may not qualify if:

• 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
• History of family history of epilepsy
• Abuse of alcoholic beverages
• Pregnancy

Sponsors & Collaborators

• Medical University of Vienna: lead

Study Sites (1)

Department of Clinical Pharmacology, Medical University of Vienna, Austria

Vienna, 1090, Austria

Location

Related Publications (1)

• 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.

  PMID: 27409462 DERIVED

MeSH Terms

Interventions

Laser-Doppler Flowmetry

Intervention Hierarchy (Ancestors)

Diagnostic Techniques, Cardiovascular; Diagnostic Techniques and Procedures; Diagnosis; Rheology; Investigative Techniques

Study Officials

• Gerhard Garhoefer, MD

  Department of Clinical Pharmacology, Medical University of Vienna

  PRINCIPAL INVESTIGATOR

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: NA
• Masking: NONE
• Purpose: BASIC SCIENCE
• Intervention Model: SINGLE GROUP
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Assoc. Prof. Dr.

Study Record Dates

• First Submitted: August 20, 2015
• First Posted: August 24, 2015
• Study Start: October 1, 2015
• Primary Completion: August 1, 2017
• Study Completion: September 1, 2017
• Last Updated: September 6, 2017

Record last verified: 2017-09

Locations

AU (1)