Diabetic Retinopathy
Conditions
Keywords
Electroretinography, Optical coherence tomography
Brief 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.
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.
Interventions
DRUGLevodopa
Patients will receive tablets of generic 25 mg carbidopa/100 mg levodopa as the drug treatment.
DRUGPlacebo
Patients will receive matching placebo tablets as the drug treatment.
Sponsors
Emory University
Morningside Center for Innovative and Affordable Medicine
Study design
Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
PREVENTION
Masking
DOUBLE (Subject, Investigator)
Masking description
Masking will be applied to diabetic participants.
Eligibility
Sex/Gender
ALL
Age
18 Years to No maximum
Healthy volunteers
Yes
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.
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| ERG with dim flash stimuli | 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
| Measure | Time frame | Description |
|---|---|---|
| Optical coherence tomography (OCT) | 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. |
| Optical coherence tomography (OCT-A) | 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. |
Countries
United States
Contacts
PRINCIPAL_INVESTIGATORAndrew Hendrick, MD
Emory University
Outcome results
None listed