Measurement of Ocular Blood Flow and Retinal Oxygen Extraction in Diabetic Patients

NCT07536516 | Recruiting DMC

• 1 other identifier: OPHT-25022025
• Study Type: interventional
• Target: 20
• Locations: 1 country
• Sites: 1

Brief 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. 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

Outcome Measures

Primary Outcomes (1)

• Ocular blood flow (LSFG)

  Ocular Blood Flow measured by Laser Speckle Flowgraphy (LSFG) in arbitrary units

  From enrollment to last study day (=5-11 weeks)

Secondary Outcomes (16)

• Retinal vessel diameter

  From enrollment to last study day (=5-11 weeks)

• Retinal oxygen saturation

  From enrollment to last study day (=5-11 weeks)

• Retinal oxygen extraction

  From enrollment to last study day (=5-11 weeks)

• Oxygen and carbon dioxide partial pressure in arterialized blood

  From enrollment to last study day (=5-11 weeks)

• Central retinal thickness

  From enrollment to last study day (=5-11 weeks)

Study Arms (1)

Diabetes mellitus GLP1-RA

EXPERIMENTAL

Measurements of the Ocular Blood Flow and Retinal Oxygen Extraction are performed.

Device: • Laser Speckle Flowgraphy (LSFG); Device: • Optical Coherence Tomography (OCT); Device: • Optical Coherence Tomography Angiography (OCT-A)

Interventions

• Laser Speckle Flowgraphy (LSFG) DEVICE

Laser Speckle Flowgraphy (LSFG)

Diabetes mellitus GLP1-RA

• Optical Coherence Tomography (OCT) DEVICE

• Optical Coherence Tomography (OCT)

Diabetes mellitus GLP1-RA

• Optical Coherence Tomography Angiography (OCT-A) DEVICE

• Optical Coherence Tomography Angiography (OCT-A)

Diabetes mellitus GLP1-RA

Eligibility Criteria

• Age: 18 Years+
• Sex: all
• Healthy Volunteers: No
• Age Groups: Adult (18-64), Older Adult (65+)

You may qualify if:

• 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

You may not qualify if:

• 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
• 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

Sponsors & Collaborators

• Medical University of Vienna: lead

Study Sites (1)

Medical University Vienna

Vienna, State of Vienna, 1090, Austria

RECRUITING

MeSH Terms

Conditions

Diabetes Mellitus

Interventions

Tomography, Optical Coherence

Condition Hierarchy (Ancestors)

Glucose Metabolism Disorders; Metabolic Diseases; Nutritional and Metabolic Diseases; Endocrine System Diseases

Intervention Hierarchy (Ancestors)

Tomography, Optical; Optical Imaging; Diagnostic Imaging; Diagnostic Techniques and Procedures; Diagnosis; Tomography; Investigative Techniques

Central Study Contacts

Doreen Schmidl, Prof. Priv. Doz. MD.; PhD

CONTACT

+431404002981; doreen.schmidl@meduniwien.ac.at

Doreen Schmidl, Prof. Priv. Doz. MD, PhD

CONTACT

+431404002981

Study Design

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

Study Record Dates

• First Submitted: June 30, 2025
• First Posted: April 17, 2026
• Study Start: November 28, 2025
• Primary Completion: May 1, 2026
• Study Completion (Estimated): June 1, 2026
• Last Updated: April 17, 2026

Record last verified: 2026-04

Locations

AU (1)