Type 2 Diabetes MellitusNCT07924618
Ocular Changes in Patients Using Tirzepatide or Semaglutide
An observational study of Type 2 Diabetes Mellitus and Obesity, run by Istanbul University at 1 site in Turkey (Türkiye).
Trial summary
This prospective observational study aims to evaluate ocular structural and microvascular changes in adults with obesity who are receiving semaglutide or tirzepatide as part of routine clinical care. Participants with and without type 2 diabetes mellitus will be included. Read more about this study
- Who is it for?
- Ages 18 years and older
- Conditions the study is for
- Type 2 Diabetes Mellitus, Obesity
- What is being tested?
- Semaglutide and Tirzepatide
- How many people
- 40 participants
- Where
- 1 siteTurkey (Türkiye)
- Study dates
- 1 Mar 2026to 17 Sep 2027
- Phase
- Observational
- 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
Study population: Adults with obesity who are receiving semaglutide or tirzepatide as part of routine clinical care will be included. Participants will include individuals with and without type 2 diabetes mellitus. The study population will be evaluated in four observational cohorts according to diabetes status and medication: obesity with diabetes receiving semaglutide, obesity with diabetes receiving tirzepatide, obesity without diabetes receiving semaglutide, and obesity without diabetes receiving tirzepatide.
Who may be able to join
- Age 18 years or older
- Diagnosis of obesity
- Receiving semaglutide or tirzepatide as part of routine clinical care
- Participants with or without type 2 diabetes mellitus
- Availability for baseline and follow-up ophthalmologic examinations
Who cannot join
- Age under 18 years
- Not receiving semaglutide or tirzepatide
- Inability to complete the required ophthalmologic examinations or imaging assessments
Trial locations and contacts
1 site in 1 country. Contact the study team or a site near you to ask about taking part.
Turkey (Türkiye)1 site, 1 recruiting
- Recruiting
Istanbul University, Istanbul Faculty of Medicine
Istanbul, Istanbul, 34093
DERYA BUDAK BEHRAD, MD, +90 545 628 0553, derya.budakbehrad@istanbul.edu.tr
ADEM TELLIOGLU, MD, +90 5066107361
About this study
Official title: Evaluation of Optic Nerve Head, Retinal Changes, and Choroidal Blood Flow in Patients With Diabetes and Obesity Using Tirzepatide or Semaglutide
This prospective observational study aims to evaluate ocular structural and microvascular changes in adults with obesity who are receiving semaglutide or tirzepatide as part of routine clinical care. Participants with and without type 2 diabetes mellitus will be included.
Participants will undergo ophthalmologic examinations at baseline and during follow-up. Changes in optic nerve head parameters, retinal thickness, retinal and choroidal microvascular parameters, and choroidal thickness will be assessed using optical coherence tomography (OCT), optical coherence tomography angiography (OCT-A), and other routine ophthalmologic examination methods.
The study will compare ocular measurements obtained at baseline and during follow-up to investigate changes associated with semaglutide or tirzepatide treatment over a period of up to 18 months.
Read the detailed description
This prospective observational cohort study will evaluate ocular structural and microvascular changes in adults with obesity receiving semaglutide or tirzepatide as part of routine clinical care. Participants will include individuals with and without type 2 diabetes mellitus.
The study population will be divided into four observational cohorts according to diabetes status and medication use:
- Participants with obesity and type 2 diabetes receiving semaglutide.
- Participants with obesity and type 2 diabetes receiving tirzepatide.
- Participants with obesity without type 2 diabetes receiving semaglutide.
- Participants with obesity without type 2 diabetes receiving tirzepatide.
Participants will undergo ophthalmologic examinations at baseline and during follow-up for up to 18 months. Assessments will include visual acuity, slit-lamp examination, intraocular pressure measurement, fundus examination, optical coherence tomography (OCT), optical coherence tomography angiography (OCT-A), and enhanced depth imaging optical coherence tomography (EDI-OCT).
The study will evaluate changes in retinal nerve fiber layer thickness, retinal thickness, superficial and deep retinal vessel density, foveal avascular zone area, choriocapillaris flow deficit percentage, and choroidal thickness. Changes in visual acuity and intraocular pressure will also be assessed.
Ocular measurements obtained at baseline and during follow-up will be compared to investigate structural and microvascular changes associated with semaglutide or tirzepatide treatment. Differences between the observational cohorts may also be evaluated.
All medications will be prescribed by the treating physicians as part of routine clinical care. Treatment selection will not be determined by the study protocol, and no experimental ophthalmologic intervention will be performed.
- Conditions
- Type 2 Diabetes Mellitus, Obesity
- Being tested
- Semaglutide, Tirzepatide
- Medical subject headings
- Diabetes Mellitus, Type 2, Obesity
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
SemaglutideDrug
Semaglutide is prescribed as part of routine clinical care. Treatment is not assigned by the study protocol. Ocular structural and vascular parameters are evaluated before treatment and during follow-up.
TirzepatideDrug
Tirzepatide is prescribed as part of routine clinical care. Treatment is not assigned by the study protocol. Ocular structural and vascular parameters are evaluated before treatment and during follow-up.
| Study group | Role | What they receive |
|---|---|---|
| Obesity With Diabetes - Semaglutide | Participants with obesity and diabetes receiving semaglutide as part of routine clinical care. Receives: Drug: Semaglutide | |
| Obesity With Diabetes - Tirzepatide | Participants with obesity and diabetes receiving tirzepatide as part of routine clinical care Receives: Drug: Tirzepatide | |
| Obesity Without Diabetes - Semaglutide | Participants with obesity without diabetes receiving semaglutide as part of routine clinical care Receives: Drug: Semaglutide | |
| Obesity Without Diabetes - Tirzepatide | Participants with obesity without diabetes receiving tirzepatide as part of routine clinical care Receives: Drug: Tirzepatide |
What is being measured
The primary outcome is the main question the study is designed to answer.
Change in Retinal Nerve Fiber Layer Thickness
Change in retinal nerve fiber layer thickness from baseline during follow-up, assessed using optical coherence tomography (OCT).
Measured: Baseline to up to 18 months
Change in Retinal Thickness
Change in retinal thickness from baseline during follow-up, assessed using optical coherence tomography (OCT).
Measured: Baseline to up to 18 months
Change in Superficial Retinal Vessel Density
Change in superficial retinal capillary vessel density from baseline to follow-up, assessed using optical coherence tomography angiography (OCT-A) and expressed as a percentage (%).
Measured: Baseline to 18 months
Change in Deep Retinal Vessel Density
Change in deep retinal capillary vessel density from baseline to follow-up, assessed using optical coherence tomography angiography (OCT-A) and expressed as a percentage (%).
Measured: Baseline to 18 months
Change in Foveal Avascular Zone Area
Change in foveal avascular zone (FAZ) area from baseline to follow-up, measured using optical coherence tomography angiography (OCT-A) and expressed in square millimeters (mm²).
Measured: Baseline to 18 months
Change in Choriocapillaris Flow Deficit Percentage
Change in choriocapillaris flow deficit percentage from baseline to follow-up, assessed using optical coherence tomography angiography (OCT-A) and expressed as a percentage (%).
Measured: Baseline to 18 months
Secondary outcomes (2)
Change in Visual Acuity
Change in visual acuity from baseline during follow-up
Measured: Baseline to up to 18 months
Change in Intraocular Pressure
Change in intraocular pressure from baseline during follow-up, measured in mmHg during routine ophthalmologic examination.
Measured: Baseline to up to 18 months
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted9 Nov 2026
- Study start1 Mar 2026
- Primary completion17 Sep 2027 (estimated)
- Study completion17 Sep 2027 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Type 2 Diabetes MellitusStudies of the same condition, open and under way.
- More trials run by Istanbul UniversityThe 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
- Observational
- Observational model
- Cohort
- Time perspective
- Prospective
- Enrolment
- 40 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Istanbul University
- Sponsor type
- University, hospital or other
- Responsible party
- Principal investigator, Derya Budak Behrad, Istanbul University
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07924618
- Sponsor's protocol ID
- 2025/2444
- Status last verified
- Oct 2026
- First submitted
- 28 Oct 2026
- Last updated
- 9 Nov 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- Yes
- FDA-regulated device
- No
- Individual data sharing
- No
Study at a glance
From the registry record, last updated by the sponsor on 9 Nov 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Evaluation of Optic Nerve Head, Retinal Changes, and Choroidal Blood Flow in Patients With Diabetes and Obesity Using Tirzepatide or Semaglutide
- ClinicalTrials.gov ID
- NCT07924618
- Acronym / sponsor ID
- 2025/2444
- Conditions
- Type 2 Diabetes Mellitus, Obesity
- Study type
- Observational
- Recruitment status
- Recruiting
- Enrolment
- 40 participants (estimated)
- Lead sponsor
- Istanbul UniversityUniversity, hospital or other
- Study start
- 1 Mar 2026 (actual)
- Primary completion
- 17 Sep 2027 (estimated)
- Study completion
- 17 Sep 2027 (estimated)
- First posted
- 9 Nov 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.
This prospective observational study aims to evaluate ocular structural and microvascular changes in adults with obesity who are receiving semaglutide or tirzepatide as part of routine clinical care. Participants with and without type 2 diabetes mellitus will be included.
Participants will undergo ophthalmologic examinations at baseline and during follow-up. Changes in optic nerve head parameters, retinal thickness, retinal and choroidal microvascular parameters, and choroidal thickness will be assessed using optical coherence tomography (OCT), optical coherence tomography angiography (OCT-A), and other routine ophthalmologic examination methods.
The study will compare ocular measurements obtained at baseline and during follow-up to investigate changes associated with semaglutide or tirzepatide treatment over a period of up to 18 months.
Detailed description
This prospective observational cohort study will evaluate ocular structural and microvascular changes in adults with obesity receiving semaglutide or tirzepatide as part of routine clinical care. Participants will include individuals with and without type 2 diabetes mellitus.
The study population will be divided into four observational cohorts according to diabetes status and medication use:
- Participants with obesity and type 2 diabetes receiving semaglutide.
- Participants with obesity and type 2 diabetes receiving tirzepatide.
- Participants with obesity without type 2 diabetes receiving semaglutide.
- Participants with obesity without type 2 diabetes receiving tirzepatide.
Participants will undergo ophthalmologic examinations at baseline and during follow-up for up to 18 months. Assessments will include visual acuity, slit-lamp examination, intraocular pressure measurement, fundus examination, optical coherence tomography (OCT), optical coherence tomography angiography (OCT-A), and enhanced depth imaging optical coherence tomography (EDI-OCT).
The study will evaluate changes in retinal nerve fiber layer thickness, retinal thickness, superficial and deep retinal vessel density, foveal avascular zone area, choriocapillaris flow deficit percentage, and choroidal thickness. Changes in visual acuity and intraocular pressure will also be assessed.
Ocular measurements obtained at baseline and during follow-up will be compared to investigate structural and microvascular changes associated with semaglutide or tirzepatide treatment. Differences between the observational cohorts may also be evaluated.
All medications will be prescribed by the treating physicians as part of routine clinical care. Treatment selection will not be determined by the study protocol, and no experimental ophthalmologic intervention will be performed.
Study design
- Observational model
- Cohort
- Time perspective
- Prospective
- Number of arms
- 4
| Arm | Type | Receives |
|---|---|---|
| Obesity With Diabetes - Semaglutide | – | Drug: SemaglutideParticipants with obesity and diabetes receiving semaglutide as part of routine clinical care. |
| Obesity With Diabetes - Tirzepatide | – | Drug: TirzepatideParticipants with obesity and diabetes receiving tirzepatide as part of routine clinical care |
| Obesity Without Diabetes - Semaglutide | – | Drug: SemaglutideParticipants with obesity without diabetes receiving semaglutide as part of routine clinical care |
| Obesity Without Diabetes - Tirzepatide | – | Drug: TirzepatideParticipants with obesity without diabetes receiving tirzepatide as part of routine clinical care |
Who may qualify
- Ages
- 18 years and older
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
- Study population
- Adults with obesity who are receiving semaglutide or tirzepatide as part of routine clinical care will be included. Participants will include individuals with and without type 2 diabetes mellitus. The study population will be evaluated in four observational cohorts according to diabetes status and medication: obesity with diabetes receiving semaglutide, obesity with diabetes receiving tirzepatide, obesity without diabetes receiving semaglutide, and obesity without diabetes receiving tirzepatide.
Key inclusion criteria (5 listed)
- Age 18 years or older
- Diagnosis of obesity
- Receiving semaglutide or tirzepatide as part of routine clinical care
- Participants with or without type 2 diabetes mellitus
- Availability for baseline and follow-up ophthalmologic examinations
Key exclusion criteria (3 listed)
- Age under 18 years
- Not receiving semaglutide or tirzepatide
- Inability to complete the required ophthalmologic examinations or imaging assessments
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 |
|---|---|---|
| SemaglutideSemaglutide is prescribed as part of routine clinical care. Treatment is not assigned by the study protocol. Ocular structural and vascular parameters are evaluated before treatment and during follow-up. | Drug | Obesity With Diabetes - Semaglutide, Obesity Without Diabetes - Semaglutide |
| TirzepatideTirzepatide is prescribed as part of routine clinical care. Treatment is not assigned by the study protocol. Ocular structural and vascular parameters are evaluated before treatment and during follow-up. | Drug | Obesity With Diabetes - Tirzepatide, Obesity Without Diabetes - Tirzepatide |
Primary outcome
Change in Retinal Nerve Fiber Layer Thickness
Time frame: Baseline to up to 18 months
Change in retinal nerve fiber layer thickness from baseline during follow-up, assessed using optical coherence tomography (OCT).
Change in Retinal Thickness
Time frame: Baseline to up to 18 months
Change in retinal thickness from baseline during follow-up, assessed using optical coherence tomography (OCT).
Change in Superficial Retinal Vessel Density
Time frame: Baseline to 18 months
Change in superficial retinal capillary vessel density from baseline to follow-up, assessed using optical coherence tomography angiography (OCT-A) and expressed as a percentage (%).
Change in Deep Retinal Vessel Density
Time frame: Baseline to 18 months
Change in deep retinal capillary vessel density from baseline to follow-up, assessed using optical coherence tomography angiography (OCT-A) and expressed as a percentage (%).
Change in Foveal Avascular Zone Area
Time frame: Baseline to 18 months
Change in foveal avascular zone (FAZ) area from baseline to follow-up, measured using optical coherence tomography angiography (OCT-A) and expressed in square millimeters (mm²).
Change in Choriocapillaris Flow Deficit Percentage
Time frame: Baseline to 18 months
Change in choriocapillaris flow deficit percentage from baseline to follow-up, assessed using optical coherence tomography angiography (OCT-A) and expressed as a percentage (%).
2 secondary outcomes
Change in Visual Acuity
Time frame: Baseline to up to 18 months
Change in Intraocular Pressure
Time frame: Baseline to up to 18 months
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 9 Nov 2026.
- Individual participant dataSharing planned: No
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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.
Istanbul University, Istanbul Faculty of Medicine
Istanbul, Turkey (Türkiye)
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
An observational study of Type 2 Diabetes Mellitus and Obesity, run by Istanbul University at 1 site in Turkey (Türkiye).
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 3 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 9 Nov 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 Turkey (Türkiye). 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?
Each site lists its own contact: choose the nearest one under Trial locations. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Change in Retinal Nerve Fiber Layer Thickness (time frame: Baseline to up to 18 months). The study lists 6 primary outcomes in all. 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 9 Nov 2026.