Diabetes MellitusDM OPF ROXYNCT07536516
Measurement of Ocular Blood Flow and Retinal Oxygen Extraction in Diabetic Patients
A study testing • Laser Speckle Flowgraphy (LSFG), • Optical Coherence Tomography (OCT) and • Optical Coherence Tomography Angiography (OCT-A) in people with Diabetes Mellitus, run by Medical University of Vienna at 1 site in Austria.
Trial summary
The prevalence of diabetes is increasing, with type 2 diabetes mellitus comprising over 90% of cases. Diabetes mellitus complications, including diabetic retinopathy (DR), impose significant health burdens. Read more about this study
- Who is it for?
- Ages 18 years and older
- Conditions the study is for
- Diabetes Mellitus
- What is being tested?
- • Laser Speckle Flowgraphy (LSFG), • Optical Coherence Tomography (OCT) and • Optical Coherence Tomography Angiography (OCT-A)
- 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
- 28 Nov 2025to 1 Jun 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 years and older
- All sexes
- No healthy volunteers
- Adult, Older adult
Who may be able to join
- Men and women aged ≥ 18 years
- Signed informed consent
- Previously diagnosed diabetes mellitus
- Normal ophthalmic findings except diabetic retinopathy, unless the investigator considers an abnormality to be clinically irrelevant
- Planned initiation of therapy with GLP-1 receptor agonist (Semaglutide, Ozempic®; Liraglutide, Victoza®) or GIP/GLP-1 receptor agonist (Tirzepatide, Mounjaro®) by a diabetes specialist
Who cannot join
- 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
- Abuse of alcoholic beverages
- Blood donation during the previous three weeks
- Presence of any abnormalities preventing reliable measurements in the study eye as judged by the investigator
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- Previous laser photocoagulation treatment in the study eye
- Best corrected visual acuity < 0.4 Snellen
- Women of childbearing potential (neither menopausal, nor hysterectomized, nor sterilized) not using effective contraception
- Pregnancy, planned pregnancy or lactation
Trial locations and contacts
1 site in 1 country. Contact the study team or a site near you to ask about taking part.
Doreen Schmidl, Prof. Priv. Doz. MD, PhD contact
Austria1 site, 1 recruiting
- Recruiting
Medical University Vienna
Vienna, State of Vienna, 1090
About this study
The prevalence of diabetes is increasing, with type 2 diabetes mellitus comprising over 90% of cases. Diabetes mellitus complications, including diabetic retinopathy (DR), impose significant health burdens. GLP-1 receptor agonists (GLP-1RAs) and dual GIP/GLP-1 receptor agonists show promise in improving cardiovascular and kidney outcomes, but their effects on retinal microvasculature and neuroprotection remain unclear. This study investigates the impact of GLP-1RAs (semaglutide, liraglutide) and GIP/GLP-1-dual agonists (tirzepatide) on ocular blood flow and retinal function in DM patients.
- Conditions
- Diabetes Mellitus
- Being tested
- • Laser Speckle Flowgraphy (LSFG), • Optical Coherence Tomography (OCT), • Optical Coherence Tomography Angiography (OCT-A)
- Medical subject headings
- Diabetes Mellitus
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
• Laser Speckle Flowgraphy (LSFG)Device
Laser Speckle Flowgraphy (LSFG)
• Optical Coherence Tomography (OCT)Device
- Optical Coherence Tomography (OCT)
• Optical Coherence Tomography Angiography (OCT-A)Device
- Optical Coherence Tomography Angiography (OCT-A)
| Study group | Role | What they receive |
|---|---|---|
| Diabetes mellitus GLP1-RA | Experimental | Measurements of the Ocular Blood Flow and Retinal Oxygen Extraction are performed. Receives: Device: • Laser Speckle Flowgraphy (LSFG); Device: • Optical Coherence Tomography (OCT); Device: • Optical Coherence Tomography Angiography (OCT-A) |
What is being measured
The primary outcome is the main question the study is designed to answer.
Ocular blood flow (LSFG)
Ocular Blood Flow measured by Laser Speckle Flowgraphy (LSFG) in arbitrary units
Measured: From enrollment to last study day (=5-11 weeks)
Secondary outcomes (16)
Retinal vessel diameter
Retinal vessel diameter with DVA
Measured: From enrollment to last study day (=5-11 weeks)
Retinal oxygen saturation
Retinal oxygen saturation with DVA
Measured: From enrollment to last study day (=5-11 weeks)
Retinal oxygen extraction
Retinal oxygen extraction will be calculated from measurements of ocular blood flow and retinal oxygen saturation. The calculation will be based on a formula integrating these parameters to estimate retinal oxygen extraction.
Unit of Measure: Arbitrary units
Measured: From enrollment to last study day (=5-11 weeks)
Oxygen and carbon dioxide partial pressure in arterialized blood
Oxygen and carbon dioxide partial pressure in arterialized blood
Measured: From enrollment to last study day (=5-11 weeks)
Central retinal thickness
Central retinal thickness with OCT
Measured: From enrollment to last study day (=5-11 weeks)
Retinal nerve fiber layer thickness
Retinal nerve fiber layer thickness with OCT
Measured: From enrollment to last study day (=5-11 weeks)
Retinal and choroidal microvasculature
Retinal and choroidal microvasculature with OCT-A
Measured: From enrollment to last study day (=5-11 weeks)
Capillary blood glucose level
Capillary blood glucose level in mg/dL
Measured: From enrollment to last study day (=5-11 weeks)
Autonomic and sensomotoric neuropathy measurements
Short-term spectral analysis of Heart rate variability (HRV) is obtained from recordings consisting of 256 seconds of artifact free recordings. Parameters of frequency-domain HRV are measured within the low-frequency band and high-frequency band, as well as total spectral variability. Outcome variables are spectral power (ms2) in both frequency bands as well as cumulative indices.
Measured: From enrollment to last study day (=5-11 weeks)
Ocular perfusion pressure
Ocular perfusion pressure is calculated from systemic blood pressure and intraocular pressure.
Unit of measurement: mmHg
Measured: From enrollment to last study day (=5-11 weeks)
Intraocular pressure
Intraocular pressure
Measured: From enrollment to last study day (=5-11 weeks)
Systemic hemodynamics - Blood pressure
Systolic and diastolic blood pressure is measured.
Unit: mmHg
Measured: From enrollment to last study day (=5-11 weeks)
Schirmer I Test
Schirmer I Test is performed.
Unit of measuremnt: mm
Measured: From enrollment to last study day (=5-11 weeks)
Finger sweat sampling
Finger sweat samples will be collected using stamped-out filter paper applied to the fingertip under standardized conditions. Samples will be analyzed using an untargeted multi-omics approach.
Proteomic, eicosadomic, and metabolomic profiles will be assessed using high-resolution mass spectrometry platforms.
Unit of Measure: Arbitrary units (normalized intensity values)
Measured: From enrollment to last study day (=5-11 weeks)
Systemic hemodynamics - Heart rate
Heart rate is measured.
Unit: Hz
Measured: From enrollment to last study day (=5-11 weeks)
Systemic hemodynamics - Oxygen saturation
Oxygen saturation is measured. Unit: %
Measured: From enrollment to last study day (=5-11 weeks)
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted17 Apr 2026
- Study start28 Nov 2025
- Primary completion1 May 2026 (estimated)
- Study completion1 Jun 2026 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Diabetes MellitusStudies of the same condition, open and under way.
- More trials run by Medical University of ViennaThe sponsor's other registered studies.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
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
- Not applicable
- Intervention model
- Single group
- Masking
- None (open label)
- Enrolment
- 20 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Medical University of Vienna
- Sponsor type
- University, hospital or other
- Responsible party
- Principal investigator, Doreen Schmidl, Medical University of Vienna
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07536516
- Sponsor's protocol ID
- OPHT-25022025
- Acronym
- DM OPF ROXY
- Status last verified
- Apr 2026
- First submitted
- 30 Jun 2025
- Last updated
- 17 Apr 2026
- Results posted
- No
- Data monitoring committee
- Yes
- FDA-regulated drug
- No
- FDA-regulated device
- No
Study at a glance
From the registry record, last updated by the sponsor on 17 Apr 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Measurement of Ocular Blood Flow and Retinal Oxygen Extraction in Diabetic Patients
- ClinicalTrials.gov ID
- NCT07536516
- Acronym / sponsor ID
- DM OPF ROXY / OPHT-25022025
- Conditions
- Diabetes Mellitus
- Study type
- Interventional
- Recruitment status
- Recruiting
- Enrolment
- 20 participants (estimated)
- Lead sponsor
- Medical University of ViennaUniversity, hospital or other
- Study start
- 28 Nov 2025 (actual)
- Primary completion
- 1 May 2026 (estimated)
- Study completion
- 1 Jun 2026 (estimated)
- First posted
- 17 Apr 2026 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
The prevalence of diabetes is increasing, with type 2 diabetes mellitus comprising over 90% of cases. Diabetes mellitus complications, including diabetic retinopathy (DR), impose significant health burdens. GLP-1 receptor agonists (GLP-1RAs) and dual GIP/GLP-1 receptor agonists show promise in improving cardiovascular and kidney outcomes, but their effects on retinal microvasculature and neuroprotection remain unclear. This study investigates the impact of GLP-1RAs (semaglutide, liraglutide) and GIP/GLP-1-dual agonists (tirzepatide) on ocular blood flow and retinal function in DM patients.
Study design
- Primary purpose
- Diagnosis
- Allocation
- Not applicable
- Intervention model
- Single group
- Masking
- None (open label)
- Number of arms
- 1
| Arm | Type | Receives |
|---|---|---|
| Diabetes mellitus GLP1-RA | Experimental | Device: • Laser Speckle Flowgraphy (LSFG), Device: • Optical Coherence Tomography (OCT), Device: • Optical Coherence Tomography Angiography (OCT-A)Measurements of the Ocular Blood Flow and Retinal Oxygen Extraction are performed. |
Who may qualify
- Ages
- 18 years and older
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (5 listed)
- Men and women aged ≥ 18 years
- Signed informed consent
- Previously diagnosed diabetes mellitus
- Normal ophthalmic findings except diabetic retinopathy, unless the investigator considers an abnormality to be clinically irrelevant
- Planned initiation of therapy with GLP-1 receptor agonist (Semaglutide, Ozempic®; Liraglutide, Victoza®) or GIP/GLP-1 receptor agonist (Tirzepatide, Mounjaro®) by a diabetes specialist
Key exclusion criteria (10 listed)
- 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
- Abuse of alcoholic beverages
- Blood donation during the previous three weeks
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| • Laser Speckle Flowgraphy (LSFG)Laser Speckle Flowgraphy (LSFG) | Device | Diabetes mellitus GLP1-RA |
| • Optical Coherence Tomography (OCT)• Optical Coherence Tomography (OCT) | Device | Diabetes mellitus GLP1-RA |
| • Optical Coherence Tomography Angiography (OCT-A)• Optical Coherence Tomography Angiography (OCT-A) | Device | Diabetes mellitus GLP1-RA |
Primary outcome
Ocular blood flow (LSFG)
Time frame: From enrollment to last study day (=5-11 weeks)
Ocular Blood Flow measured by Laser Speckle Flowgraphy (LSFG) in arbitrary units
16 secondary outcomes
Retinal vessel diameter
Time frame: From enrollment to last study day (=5-11 weeks)
Retinal oxygen saturation
Time frame: From enrollment to last study day (=5-11 weeks)
Retinal oxygen extraction
Time frame: From enrollment to last study day (=5-11 weeks)
Oxygen and carbon dioxide partial pressure in arterialized blood
Time frame: From enrollment to last study day (=5-11 weeks)
Central retinal thickness
Time frame: From enrollment to last study day (=5-11 weeks)
Retinal nerve fiber layer thickness
Time frame: From enrollment to last study day (=5-11 weeks)
Retinal and choroidal microvasculature
Time frame: From enrollment to last study day (=5-11 weeks)
Capillary blood glucose level
Time frame: From enrollment to last study day (=5-11 weeks)
Autonomic and sensomotoric neuropathy measurements
Time frame: From enrollment to last study day (=5-11 weeks)
Ocular perfusion pressure
Time frame: From enrollment to last study day (=5-11 weeks)
Intraocular pressure
Time frame: From enrollment to last study day (=5-11 weeks)
Systemic hemodynamics - Blood pressure
Time frame: From enrollment to last study day (=5-11 weeks)
Schirmer I Test
Time frame: From enrollment to last study day (=5-11 weeks)
Finger sweat sampling
Time frame: From enrollment to last study day (=5-11 weeks)
Systemic hemodynamics - Heart rate
Time frame: From enrollment to last study day (=5-11 weeks)
Systemic hemodynamics - Oxygen saturation
Time frame: From enrollment to last study day (=5-11 weeks)
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 17 Apr 2026.
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part.
Doreen Schmidl, Prof. Priv. Doz. MD, PhD contact
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing • Laser Speckle Flowgraphy (LSFG), • Optical Coherence Tomography (OCT) and • Optical Coherence Tomography Angiography (OCT-A) in people with Diabetes Mellitus, 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 5 inclusion and 10 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 17 Apr 2026. 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, Prof. Priv. Doz. MD.; PhD (+431404002981, 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?
Ocular blood flow (LSFG) (time frame: From enrollment to last study day (=5-11 weeks)). 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 17 Apr 2026.