Diabetes Mellitus
Conditions
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.
Interventions
DEVICE• Laser Speckle Flowgraphy (LSFG)
Laser Speckle Flowgraphy (LSFG)
DEVICE• Optical Coherence Tomography (OCT)
• Optical Coherence Tomography (OCT)
DEVICE• Optical Coherence Tomography Angiography (OCT-A)
• Optical Coherence Tomography Angiography (OCT-A)
Sponsors
Medical University of Vienna
Study design
Allocation
NA
Intervention model
SINGLE_GROUP
Primary purpose
DIAGNOSTIC
Masking
NONE
Eligibility
Sex/Gender
ALL
Age
18 Years to No maximum
Healthy volunteers
No
Inclusion criteria
* 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
Exclusion criteria
* 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
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Ocular blood flow (LSFG) | From enrollment to last study day (=5-11 weeks) | Ocular Blood Flow measured by Laser Speckle Flowgraphy (LSFG) in arbitrary units |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Retinal vessel diameter | From enrollment to last study day (=5-11 weeks) | Retinal vessel diameter with DVA |
| Retinal oxygen saturation | From enrollment to last study day (=5-11 weeks) | Retinal oxygen saturation with DVA |
| Retinal oxygen extraction | From enrollment to last study day (=5-11 weeks) | 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 |
| Oxygen and carbon dioxide partial pressure in arterialized blood | From enrollment to last study day (=5-11 weeks) | Oxygen and carbon dioxide partial pressure in arterialized blood |
| Central retinal thickness | From enrollment to last study day (=5-11 weeks) | Central retinal thickness with OCT |
| Retinal nerve fiber layer thickness | From enrollment to last study day (=5-11 weeks) | Retinal nerve fiber layer thickness with OCT |
| Retinal and choroidal microvasculature | From enrollment to last study day (=5-11 weeks) | Retinal and choroidal microvasculature with OCT-A |
| Capillary blood glucose level | From enrollment to last study day (=5-11 weeks) | Capillary blood glucose level in mg/dL |
| Autonomic and sensomotoric neuropathy measurements | From enrollment to last study day (=5-11 weeks) | 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. |
| Ocular perfusion pressure | From enrollment to last study day (=5-11 weeks) | Ocular perfusion pressure is calculated from systemic blood pressure and intraocular pressure. Unit of measurement: mmHg |
| Intraocular pressure | From enrollment to last study day (=5-11 weeks) | Intraocular pressure |
| Systemic hemodynamics - Blood pressure | From enrollment to last study day (=5-11 weeks) | Systolic and diastolic blood pressure is measured. Unit: mmHg |
| Schirmer I Test | From enrollment to last study day (=5-11 weeks) | Schirmer I Test is performed. Unit of measuremnt: mm |
| Finger sweat sampling | From enrollment to last study day (=5-11 weeks) | 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) |
| Systemic hemodynamics - Heart rate | From enrollment to last study day (=5-11 weeks) | Heart rate is measured. Unit: Hz |
| Systemic hemodynamics - Oxygen saturation | From enrollment to last study day (=5-11 weeks) | Oxygen saturation is measured. Unit: % |
Countries
Austria
Contacts
CONTACTDoreen Schmidl, Prof. Priv. Doz. MD.; PhD
CONTACTDoreen Schmidl, Prof. Priv. Doz. MD, PhD
Outcome results
None listed