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OpenTrials
Completed

NCT Number: NCT07444892

Levodopa for Diabetic Retinopathy

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.

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Key information

Conditions

Diabetic Retinopathy Cardiovascular Diseases Diabetes Complications Diabetes Mellitus Diabetic Angiopathies Endocrine System Diseases Eye Diseases Retinal Diseases Vascular Diseases

Age range

18 year and older

Sex eligibility

All sexes

Study type

Interventional

Phase

Phase 2

Primary location

Atlanta VA Medical Center

Decatur, Georgia, 30033, United States

About this study

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.

Who can participate

Healthy volunteers accepted: Yes

Only the study team can determine whether someone qualifies for participation.

Inclusion criteria

  • Adults
  • diagnosed with diabetes mellitus

Exclusion criteria

  • 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.

Treatment and study plan

levodopa

Drug

Patients will receive tablets of generic 25 mg carbidopa/100 mg levodopa as the drug treatment.

Placebo

Drug

Patients will receive matching placebo tablets as the drug treatment.

Primary outcomes

  1. 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.

Secondary outcomes

  1. Optical coherence tomography (OCT)

    Time frame: Baseline, 3 and 6 months post-intervention

    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.

  2. Optical coherence tomography (OCT-A)

    Time frame: Baseline, 3 and 6 months post-intervention

    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.

Sponsors and collaborators

Lead sponsor

Emory University

Other

Collaborators

  • Morningside Center for Innovative and Affordable Medicine

Registry information

Important dates

Study start
2022
Primary completion
2025
Study completion
2025
First posted
Mar 3, 2026
Registry last updated
Mar 3, 2026

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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