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Retinal Blood FlowNCT03552562

Measurement of Total Retinal Blood Flow and Oxygen Extraction in Patients With Diabetes and Healthy Subjects

A study testing Fourier Domain Color Doppler Optical Coherence Tomography (FDOCT) in people with Retinal Blood Flow, run by Medical University of Vienna at 1 site in Austria.

Recruiting

Looking for participants now. Contact the study team or a site below to ask about taking part.

Sites and contacts
Official record
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Trial summary

The prevalence of diabetes and diabetes-associated complications is still increasing. Several major long-term complications of diabetes such as cardiovascular disease, chronic renal failure, diabetic retinopathy and others relate to the damage of blood vessels. Read more about this study

Who is it for?
Ages 18 to 99 yearsHealthy volunteers can take part
Conditions the study is for
Retinal Blood Flow
What is being tested?
Fourier Domain Color Doppler Optical Coherence Tomography (FDOCT)
Type of treatment
Medical device
Could I receive a placebo?
No, everyone receives an active treatment
How many people
120 participants
Where
1 siteAustria
Study dates
21 Nov 2018to 9 Mar 2026
Phase
Interventional
Are there results?
Not yet: the study is under way

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 99 years
  • All sexes
  • Healthy volunteers accepted
  • Adult, Older adult

Who may be able to join

  • Men and women aged over 18 years
  • Non-smokers
  • Normal findings in the medical history unless the investigator considers an abnormality to be clinically irrelevant
  • Normal ophthalmic findings, ametropy < 6 Dpt.
  • Men and women aged over 18 years
  • Non-smokers
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  • Previously diagnosed type II diabetes
  • No, mild, moderate or severe non-proliferative diabetic retinopathy
  • Normal ophthalmic findings except mild diabetic retinopathy, ametropy < 6 Dpt.

Who cannot join

  • Symptoms of a clinically relevant illness in the 3 weeks before the first study day
  • Presence or history of a severe medical condition as judged by the clinical investigator
  • Regular use of medication, abuse of alcoholic beverages, participation in a clinical trial in the 3 weeks preceding the study (except oral contraceptive)
  • untreated arterial hypertension (defined as either systolic blood pressure >145 mmHg or diastolic blood pressure >90 mmHg)
  • Blood donation during the previous three weeks
  • History or family history of epilepsy
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  • Presence of any abnormalities preventing reliable measurements in the study eye as judged by the investigator
  • Best corrected visual acuity < 0.8 Snellen
  • Ametropy ≥ 6 Dpt
  • Pregnancy, planned pregnancy or lactating
  • Participation in a clinical trial in the 3 weeks preceding the screening visit
  • Symptoms of a clinically relevant illness in the 3 weeks before the first study day
  • Presence or history of a severe medical condition, except diabetes, as judged by the clinical investigator
  • untreated arterial hypertension (defined as either systolic blood pressure >145 mmHg or diastolic blood pressure >90 mmHg)
  • Blood donation during the previous three weeks
  • Moderate to severe non-proliferative or proliferative diabetic retinopathy
  • Previous laser photocoagulation treatment
  • History or family history of epilepsy
  • Presence of any abnormalities preventing reliable measurements in the study eye as judged by the investigator
  • Best corrected visual acuity < 0.8 Snellen
  • Ametropy ≥ 6 Dpt
  • Pregnancy, planned pregnancy or lactating

Trial locations and contacts

1 site in 1 country. Contact the study team or a site near you to ask about taking part.

Austria1 site, 1 recruiting
  • Department of Clinical Pharmacology, Medical University of Vienna, Austria

    Vienna, 1090

    Gerhard Garhofer, MD, +43 1 40400 ext. 29810, gerhard.garhoefer@meduniwien.ac.at

    Recruiting

Other trials in Austria

About this study

The prevalence of diabetes and diabetes-associated complications is still increasing. Several major long-term complications of diabetes such as cardiovascular disease, chronic renal failure, diabetic retinopathy and others relate to the damage of blood vessels. Given that the eye provides the unique possibility in the human body to directly visualize blood vessels, much interest has been directed towards studying the ocular circulation and retinal oxygen metabolism.

Although data of large epidemiological studies indicate that changes in retinal vessel caliber reflect other diabetes related factors, such as fasting glucose levels, there is still conflicting evidence on blood flow alterations in patients with diabetes. Strongly related to ocular blood flow, investigation of retinal oxygen metabolism has received a lot attention. In particular, hypoxia is assumed to be major trigger of neovascularisation in the retinal of diabetic patients The present study seeks to investigate both ocular blood flow and tissue oxygen extraction in patients with type II diabetes. For this purpose, total retinal blood flow will be assessed with bi-directional Fourier Domain Doppler Optical Coherence Tomography (FDOCT). Furthermore, retinal oxygen saturation will be measured non-invasively by a fundus camera based system. Based on data of retinal blood flow and retinal oxygen saturation, retinal oxygen. This will help to better understand ocular blood flow changes and oxygen metabolism in patients with type II diabetes.

Being tested
Fourier Domain Color Doppler Optical Coherence Tomography (FDOCT)

What participants receive

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

  • Fourier Domain Color Doppler Optical Coherence Tomography (FDOCT)Device

    Fourier domain OCT is based on a local phase analysis of the backscattered signal and allows for bidirectional Doppler flow imaging.(Leitgeb et al. 2003a; Leitgeb et al. 2003b) It does not need reference arm scanning and records one full depth and Doppler profile in parallel. The system operates with an equivalent A-scan rate of 25 kHz and allows real time imaging of the color encoded Doppler information together with the tissue morphology at a rate of 2-4 tomograms (40 x 512 pixel) per second. Despite the high detection speed we achieve a system sensitivity of 86dB using a beam power of 500μW at the cornea. The fundus camera allows simultaneous view for selection of the region of interest. We observe bi-directional blood flow and pulsatility of blood velocity in retinal vessels with a Doppler detection bandwidth of 12.5 kHz and a longitudinal velocity sensitivity in tissue of 200μm/s. Diffuse luminance flicker will be applied during the measurements for 60 seconds.

Study groups in NCT03552562
Study groupRoleWhat they receive
30 patients with no signs of diabetic retinopathyOtherNot described
Receives: Device: Fourier Domain Color Doppler Optical Coherence Tomography (FDOCT)
30 patients with mild diabetic retinopathyOtherNot described
Receives: Device: Fourier Domain Color Doppler Optical Coherence Tomography (FDOCT)
30 patients with moderate to severe diabetic retinopathyOtherNot described
Receives: Device: Fourier Domain Color Doppler Optical Coherence Tomography (FDOCT)
30 healthy age-and sex- matched control subjectsOtherNot described
Receives: Device: Fourier Domain Color Doppler Optical Coherence Tomography (FDOCT)

What is being measured

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

  1. Total retinal blood flow (DVA and FDOCT)

    To determine the total blood flow in the eye, OCT measurements were performed with a rectangular scanning pattern around the optical nerve head.

    Measured: 60 minutes

Timeline

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

  1. First posted12 Jun 2018
  2. Study start21 Nov 2018
  3. Primary completion9 Mar 2026 (estimated)
  4. Study completion9 Mar 2026 (estimated)

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
Diagnosis
Allocation
Non-randomised
Intervention model
Parallel groups
Masking
Single blind
Who is masked
Outcomes assessor
Enrolment
120 participants (estimated)
IDs, dates and publications
ClinicalTrials.gov ID
NCT03552562
Sponsor's protocol ID
OPHT-100218
Status last verified
Apr 2025
First submitted
29 May 2018
Last updated
23 May 2025
Results posted
No
Data monitoring committee
No
FDA-regulated drug
No
FDA-regulated device
No
Individual data sharing
No

Questions about this trial

What is this clinical trial studying?

A study testing Fourier Domain Color Doppler Optical Coherence Tomography (FDOCT) in people with Retinal Blood Flow, 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 9 inclusion and 22 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: looking for participants now, as of the sponsor's last update on 23 May 2025. 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?

This study is still under way. Results are not available in the source record yet.

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

Contact Doreen Schmidl (+4314040029880, doreen.schmidl@meduniwien.ac.at), or a site near the patient. AzTrials does not enrol participants or take referrals.

What does the primary outcome measure?

Total retinal blood flow (DVA and FDOCT) (time frame: 60 minutes). It is what the study was designed to measure, not a finding.

Where can I read the original study information?
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 23 May 2025.

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