Diabetic RetinopathyPhase 2NCT07444892
Levodopa for Diabetic Retinopathy
A Phase 2 study testing Levodopa in people with Diabetic Retinopathy, run by Emory University at 1 site in United States.
Trial summary
The purpose of this study is to determine optimum dosing strategies of levodopa and determine the physiologic mechanisms that provide the therapeutic response to restore abnormalities in the electrical conductivity of the retina in people with diabetes and no clinically visible retinopathy. Read more about this study
- Who is it for?
- Ages 18 years and olderHealthy volunteers can take part
- Conditions the study is for
- Diabetic Retinopathy
- What is being tested?
- Levodopa
- Type of treatment
- Pill or oral medicine
- Could I receive a placebo?
- Yes, some participants may receive a placebo
- How many people
- 230 participants
- Where
- 1 siteUnited States
- Study dates
- 18 Apr 2022to 17 Nov 2025
- Phase
- Phase 2
- Are there results?
- None posted in the registry
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
- Healthy volunteers accepted
- Adult, Older adult
Who may be able to join
- Adults
- diagnosed with diabetes mellitus
Who cannot join
- taking dopamine effecting drugs
- have a pituitary tumor
- psychosis, Parkinson's disease
- cognitive deficits
- confounding ocular disease
- Control Participants:
- Non-diabetic participants with no visual problems to create control measurements.
Trial locations and contacts
1 site in 1 country.
About this study
The purpose of this study is to determine optimum dosing strategies of levodopa and determine the physiologic mechanisms that provide the therapeutic response to restore abnormalities in the electrical conductivity of the retina in people with diabetes and no clinically visible retinopathy.
Read the detailed description
This study is investigating the optimal timing of using levodopa in reducing damage in the retina from diabetes mellitus. Adult subjects will be recruited from the Atlanta VA Eye clinic and randomized to one of four arms: placebo, levodopa every other day, levodopa daily, or levodopa twice daily. Each group include participants that will receive treatment for 6 months with eye exams and testing conducted at baseline, 3 month, and 6 month visits. Testing at the visits includes electroretinograms, fundus photography, optical coherence tomography with angiography, and HbA1c serology. Veterans will sign the consent, in-person prior to beginning study activities.
- Conditions
- Diabetic Retinopathy
- Being tested
- Levodopa, Placebo
- Keywords
- Electroretinography, Optical coherence tomography
- Medical subject headings
- Diabetic Retinopathy
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
LevodopaDrug
Patients will receive tablets of generic 25 mg carbidopa/100 mg levodopa as the drug treatment.
PlaceboDrug
Patients will receive matching placebo tablets as the drug treatment.
| Study group | Role | What they receive |
|---|---|---|
| Placebo | Active comparator | Diabetic participants will be instructed to take the oral placebo daily with a meal for 6 months. Receives: Drug: Placebo |
| Levodopa every other day | Experimental | Diabetic participants will be instructed to take the levodopa every other day with a meal for 6 months. Receives: Drug: Levodopa |
| Levodopa once per day | Experimental | Diabetic participants will be instructed to take the oral levodopa daily with a meal for 6 months.. Receives: Drug: Levodopa |
| Levodopa twice per day | Experimental | Diabetic participants in the twice per day group will be instructed to take the drug 12 hours apart every day for 6 months. Receives: Drug: Levodopa |
What is being measured
The primary outcome is the main question the study is designed to answer.
ERG with dim flash stimuli
Full-field electroretinography (ERG) will be performed to assess rod-mediated retinal function. A skin electrode placed below the eye records the response to flash stimuli. Participants will be dark-adapted for 10 minutes to sensitive retinal rod pathways. Flash stimuli will consist of dim (1.13 Td) or bright (85 Td) flashes to reveal early dysfunction in DR.
Measured: Baseline, 3 and 6 months post-intervention
Secondary outcomes (2)
Optical coherence tomography (OCT)
Optical coherence tomography (OCT) will be done with the Heidelberg SLO+HRA to image the retina. The retinal vessels and retinal layers will be analyzed for any abnormalities.
Measured: Baseline, 3 and 6 months post-intervention
Optical coherence tomography (OCT-A)
Optical coherence tomography (OCT) will be done with the Heidelberg SLO+HRA with an angiography module to image the retina. Percent of retinal area with perfusion abnormality will be calculated.
Measured: Baseline, 3 and 6 months post-intervention
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted3 Mar 2026
- Study start18 Apr 2022
- Primary completion17 Nov 2025
- Study completion17 Nov 2025
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Diabetic RetinopathyStudies of the same condition, open and under way.
- More trials run by Emory 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
- Interventional
- Phase
- Phase 2
- Primary purpose
- Prevention
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Double blind
- Who is masked
- Participant, Investigator
- Enrolment
- 230 participants (actual)
Sponsor and investigators
- Lead sponsor
- Emory University
- Sponsor type
- University, hospital or other
- Collaborators
- Morningside Center for Innovative and Affordable Medicine
- Responsible party
- Principal investigator, Andrew Hendrick, Emory University
- Investigators
- Andrew Hendrick, MD, Principal investigator, Emory University
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07444892
- Sponsor's protocol ID
- STUDY00002995
- Other IDs
- 2025P013031
- Status last verified
- Feb 2026
- First submitted
- 25 Feb 2026
- Last updated
- 3 Mar 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 3 Mar 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Levodopa for Diabetic Retinopathy
- ClinicalTrials.gov ID
- NCT07444892
- Acronym / sponsor ID
- STUDY00002995
- Conditions
- Diabetic Retinopathy
- Keywords
- Electroretinography, Optical coherence tomography
- Phase
- Phase 2
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 230 participants (actual)
- Lead sponsor
- Emory UniversityUniversity, hospital or other
- Collaborators
- Morningside Center for Innovative and Affordable Medicine
- Study start
- 18 Apr 2022 (actual)
- Primary completion
- 17 Nov 2025 (actual)
- Study completion
- 17 Nov 2025 (actual)
- First posted
- 3 Mar 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 purpose of this study is to determine optimum dosing strategies of levodopa and determine the physiologic mechanisms that provide the therapeutic response to restore abnormalities in the electrical conductivity of the retina in people with diabetes and no clinically visible retinopathy.
Detailed description
This study is investigating the optimal timing of using levodopa in reducing damage in the retina from diabetes mellitus. Adult subjects will be recruited from the Atlanta VA Eye clinic and randomized to one of four arms: placebo, levodopa every other day, levodopa daily, or levodopa twice daily. Each group include participants that will receive treatment for 6 months with eye exams and testing conducted at baseline, 3 month, and 6 month visits. Testing at the visits includes electroretinograms, fundus photography, optical coherence tomography with angiography, and HbA1c serology. Veterans will sign the consent, in-person prior to beginning study activities.
Study design
- Primary purpose
- Prevention
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Double blind (participant, investigator)
- Number of arms
- 4
| Arm | Type | Receives |
|---|---|---|
| Placebo | Active comparator | Drug: PlaceboDiabetic participants will be instructed to take the oral placebo daily with a meal for 6 months. |
| Levodopa every other day | Experimental | Drug: LevodopaDiabetic participants will be instructed to take the levodopa every other day with a meal for 6 months. |
| Levodopa once per day | Experimental | Drug: LevodopaDiabetic participants will be instructed to take the oral levodopa daily with a meal for 6 months.. |
| Levodopa twice per day | Experimental | Drug: LevodopaDiabetic participants in the twice per day group will be instructed to take the drug 12 hours apart every day for 6 months. |
Who may qualify
- Ages
- 18 years and older
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (2 listed)
- Adults
- diagnosed with diabetes mellitus
Key exclusion criteria (7 listed)
- taking dopamine effecting drugs
- have a pituitary tumor
- psychosis, Parkinson's disease
- cognitive deficits
- confounding ocular disease
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 |
|---|---|---|
| LevodopaPatients will receive tablets of generic 25 mg carbidopa/100 mg levodopa as the drug treatment. | Drug | Levodopa every other day, Levodopa once per day, Levodopa twice per day |
| PlaceboPatients will receive matching placebo tablets as the drug treatment. | Drug | Placebo |
Primary outcome
ERG with dim flash stimuli
Time frame: Baseline, 3 and 6 months post-intervention
Full-field electroretinography (ERG) will be performed to assess rod-mediated retinal function. A skin electrode placed below the eye records the response to flash stimuli. Participants will be dark-adapted for 10 minutes to sensitive retinal rod pathways. Flash stimuli will consist of dim (1.13 Td) or bright (85 Td) flashes to reveal early dysfunction in DR.
2 secondary outcomes
Optical coherence tomography (OCT)
Time frame: Baseline, 3 and 6 months post-intervention
Optical coherence tomography (OCT-A)
Time frame: Baseline, 3 and 6 months post-intervention
Results and safety
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 3 Mar 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. This study is not recruiting at the moment.
Andrew Hendrick, MD principal investigator
Emory University
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A Phase 2 study testing Levodopa in people with Diabetic Retinopathy, run by Emory University at 1 site in United States.
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 2 inclusion and 7 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: finished, as of the sponsor's last update on 3 Mar 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 United States. 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.
What does this phase mean?
Phase 2 studies give the treatment to a larger group to see whether it has the intended effect and to keep checking safety.
Not every study follows the same path, and some studies (observational studies, device studies) have no phase.
Are results available for this study?
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
ERG with dim flash stimuli (time frame: Baseline, 3 and 6 months post-intervention). 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 3 Mar 2026.