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CompletedNCT02706977Dopamine DRUpdated Oct 9, 2019

The Effect of Dopamine on Diabetic Retinopathy

A Phase 1 interventional study of Low Dose Sinemet CR and High Dose Sinemet CR in Diabetes, sponsored by Emory University. Completed at 1 site in United States. Open to participants aged 18 Years to 80 Years, including healthy volunteers. Per ClinicalTrials.gov, last updated 2019-10-09.

Sponsored by Emory University · Phase 1, Interventional, and Treatment

Phase
Phase 1
Study type
Interventional
Enrollment
60
Allocation
Randomized
Ages
18 Years to 80 Years
Sex
All
01

Study summary

The purpose of this study is to evaluate the use of electroretinogram (ERG) using a novel handheld system, RETeval, and evaluate contrast sensitivity testing in detecting pre-clinical retinopathy on a tablet device.

Investigators also seek to assess if a medication called Sinemet™ CR can improve the electrical functions of the eye in participants with diabetes mellitus. This study will include a total of 45 participants; 30 with diabetes mellitus and 15 age-matched non-diabetic controls. Participants with diabetes mellitus and electroretinogram (ERG) delays will be randomized to a low or high dose Sinemet CR group.

Read the detailed description

The purpose of this study is to evaluate the use of electroretinogram (ERG) using a novel handheld system, RETeval, and evaluate contrast sensitivity testing in detecting pre-clinical retinopathy on a tablet device.

Investigators also seek to assess if a medication called Sinemet™ CR can improve the electrical functions of the eye in participants with diabetes mellitus. This study will include a total of 45 participants; 30 with diabetes mellitus and 15 age-matched non-diabetic controls. Participants with diabetes mellitus and electroretinogram (ERG) delays will be randomized to a low or high dose Sinemet™ CT group.

Age-matched controls will not receive Sinemet Ct drug treatment.

The study involves four visits over the course of 4 weeks, each visit consisting of 2-3 hours. Visual testing will be performed at 1 day and 2 weeks following treatment. The drug treatment will be halted and testing repeated again after a 2 week wash-out period.

02

Conditions studied

  • Diabetes

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Keywords

  • Ophthalmology
03

In context

Diabetes Mellitus

11,090 studies on the registry are indexed under Diabetes Mellitus; 1,319 are open to participants now.

This study's enrollment of 60 is below the median of 80 across 8,491 interventional studies indexed under Diabetes Mellitus.

Browse Diabetes Mellitus studies →

Lead sponsor

Emory University is the lead sponsor of 1,405 studies on the registry; 233 are open to participants now.

Of its 233 completed or terminated interventional studies of FDA-regulated products, 176 (76%) have results posted.

Counted across the registry records on this site, refreshed daily.

04

Who can participate

Ages eligible
18 Years to 80 Years
Sexes eligible
All
Accepts healthy volunteers
Yes

Go through the criteria one by one — yes, no or not sure — and take the list to your doctor or the study team. Kept in this browser only.

Inclusion criteria

Participants with Diabetes Mellitus:

  • Diagnosis of diabetes mellitus type-2
  • HbA1c between 8 and 12%

Age-Matched Controls:

  • Non-diabetic

Exclusion criteria

Exclusion Criteria

Participants with Diabetes Mellitus:

  • Currently taking dopamine-enhancing drugs (L-DOPA, bromocriptine)
  • Currently taking nonselective monoamine oxidase (MAO) inhibitors
  • Diagnosis of psychosis, Parkinson's disease, restless leg syndrome, major depression, confounding ocular disease (eg. visually significant cataract, glaucoma, macular degeneration, or retinitis pigmentosa)
  • Pregnancy

Age-Matched Controls:

  • Diabetes diagnosis
  • Currently taking dopamine-enhancing drugs (L-DOPA, bromocriptine)
  • Currently taking nonselective monoamine oxidase (MAO) inhibitors
  • Diagnosis of psychosis, Parkinson's disease, restless leg syndrome, major depression, confounding ocular disease (eg. visually significant cataract, glaucoma, macular degeneration, or retinitis pigmentosa)
  • Pregnancy
05

Study design

Phase
Phase 1
Primary purpose
Treatment
Allocation
Randomized
Intervention model
Parallel assignment
Masking
Double (Participant, Investigator)
Enrollment
60 participants (actual)

Study arms

  • Experimental
    Diabetes Group - Low Dose Sinemet CR

    Participants with diabetes mellitus type-2 and electroretinogram (ERG) delays will receive low dose Sinemet CR twice daily for two weeks.

    Drug: Low Dose Sinemet CR · Device: RETeval Electroretinogram (ERG) Testing · Other: Contrast Sensitivity Testing · Other: Visual Acuity Testing

  • Experimental
    Diabetes Group - High Dose Sinemet CR

    Participants with diabetes mellitus type-2 and electroretinogram (ERG) delays will receive high dose Sinemet CR twice daily for two weeks.

    Drug: High Dose Sinemet CR · Device: RETeval Electroretinogram (ERG) Testing · Other: Contrast Sensitivity Testing · Other: Visual Acuity Testing

  • Other
    Diabetes Group - No Electroretinogram (ERG) Delays

    Participants with diabetes mellitus type-2 who do not have electroretinogram (ERG) delays. Participants in this group will have one baseline visit only.

    Device: RETeval Electroretinogram (ERG) Testing · Other: Contrast Sensitivity Testing · Other: Visual Acuity Testing

  • Other
    Age-Matched Controls

    Participants will serve as age-matched controls for participants with diabetes. This group will participate in the baseline, week 2, and week 4 visits only.

    Device: RETeval Electroretinogram (ERG) Testing · Other: Contrast Sensitivity Testing · Other: Visual Acuity Testing

Interventions

  • DrugLow Dose Sinemet CR

    Sinemet CR (25 mg carbidopa/100 mg levodopa) will be taken by mouth twice daily for two weeks.

  • DrugHigh Dose Sinemet CR

    Sinemet CR (50 mg carbidopa/200 mg levodopa) will be taken by mouth twice daily for two weeks.

  • DeviceRETeval Electroretinogram (ERG) Testing

    ERG testing consists of sitting in the dark for 15 minutes. During the procedure, participants will have a single-use adhesive sensor strip placed on the skin near the eye. A hand-held device, called the RETeval, will be placed in front of the eye and a series of flashes and flickering lights presented. The light intensity level is typically not uncomfortable. When right eye imaging is complete, the procedure will be repeated on the left eye. Both eyes will be evaluated in less than 5 minutes for most participants. Electroretinogram (ERG) testing will be completed at baseline, day 1, week 2, and week 4.

  • OtherContrast Sensitivity Testing

    Contrast sensitivity testing consists of looking at a series of moving lines on a tablet device. The lines will change from white to grey to black. Participants will be asked to determine when they can no longer distinguish between the lines. Contrast sensitivity testing will be completed at baseline, day 1, week 2, and week 4.

  • OtherVisual Acuity Testing

    Participants will be asked to look at an eye chart with letters or symbols that become smaller as they move from top to bottom of the chart. Visual acuity testing will be completed at baseline, day 1, week 2, and week 4.

06

What researchers measure

Primary outcomes

  1. Change in Retinal Function assessed by Electroretinogram (ERG) Device

    The RETeval device consists of a hand-held wand with a pupil tracker. A skin electrode placed below the eye or DTL fiber records the response to flash stimuli. The pupil tracker provides feedback to the system so that the flash stimuli can compensate for the pupil size and produce the proper illumination to the retina. RETeval is intended to generate photopic signals and measure and display the electrical response signals generated by the retina and the visual nervous system using flash stimuli.

    Time frame: Baseline, Week 4

  2. Change in Contrast Sensitivity assessed by the Contrast Sensitivity Function v1.0 (CSF v1.0) Tablet Application

    Participants will view the screen monocularly while wearing their normal correction. A drifting grating will be presented at 60 cm for 3, 6, 12 and 18 c/d. Following photopic testing (100 lux), the participant will be dark-adapted and a neutral density filter will be applied to the tablet screen to produce luminance of \~1 lux.

    Time frame: Baseline, Week 4

  3. Change in Contrast Sensitivity assessed by the Sine Wave Grafting Test (CSV-1000E)

    The CSV-1000E is self-illuminated (85 cd/m2). A drifting grating will be presented at 60 cm for 3, 6, 12 and 18 c/d. The participant will view the chart from 2.5m. The intensity of the CSV-1000 will be reduced to 1 lux with neutral density filters for scotopic testing.

    Time frame: Baseline, Week 4

  4. Change in Visual Acuity assessed by the Standard Snellen Static Chart

    The common Snellen chart is printed with eleven lines of block letters. The first line consists of one very large letter, which may be one of several letters, for example E, H, or N. Subsequent rows have increasing numbers of letters that decrease in size. Participants will cover one eye from 6 metres or 20 feet away, and read aloud the letters of each row, beginning at the top. The smallest row that can be read accurately indicates the visual acuity in that specific eye. The test will be repeated covering the opposite eye.

    Time frame: Baseline, Week 4

07

Study locations

1 site
  • Atlanta VA Medical Center
    Atlanta, Georgia 30033, United States
08

References and documents

Publications

  • Motz CT, Chesler KC, Allen RS, Bales KL, Mees LM, Feola AJ, Maa AY, Olson DE, Thule PM, Iuvone PM, Hendrick AM, Pardue MT. Novel Detection and Restorative Levodopa Treatment for Preclinical Diabetic Retinopathy. Diabetes. 2020 Jul;69(7):1518-1527. doi: 10.2337/db19-0869. Epub 2020 Feb 12. PubMed 32051147 ↗
09

Timeline

Tracking since Sep 25, 2026
Not marked actual or estimatedDates not marked actual or estimated

The record gives a start of Jan 2016, a primary completion of Aug 2019 and a completion of Aug 2019. It does not say whether these dates are actual or estimated.

How these figures are worked out, and which studies are left out of them.

Registered
Mar 4, 2016
First posted
Mar 11, 2016
Start
Jan 2016
Primary completionActual
Aug 15, 2019
CompletionActual
Aug 15, 2019
Last update
Oct 9, 2019
What these dates mean
Start.
When the first participant enrolled; while estimated, when the study expects to open to recruitment.
Primary completion.
When the last participant was examined or treated to collect data for the study's main question, its primary outcome. A study that stopped early gives the date its data collection stopped.
Completion.
When the last participant's last visit took place, for every outcome, secondary ones and side effects included: the end of the study. Often later than primary completion, sometimes the same day.
Actual and Est.
Actual means the registry says the date has happened. Est. (estimated) is a date the sponsor plans or expects. It can still move, and the sponsor is expected to change it to actual once it has passed.
No changes since tracking began. The registry record was last updated on Oct 9, 2019, before this site started recording changes on Sep 25, 2026. Its history is on ClinicalTrials.gov ↗
10

Registry details

Key details

Study ID
NCT02706977
Lead sponsor
Emory University
Responsible party
Machelle Pardue (Adjunct Professor, Emory University) — Principal investigator
First posted
Mar 11, 2016
Start date
Jan 2016
Primary completion
Aug 15, 2019
Completion
Aug 15, 2019
Last update
Oct 9, 2019

Study contacts

Machelle Pardue, PhD
principal investigator · Emory University

Oversight

Data monitoring committee
Yes
View the source record on ClinicalTrials.gov ↗

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This study is completed, as verified in Oct 2019. You cannot join it, but the record below documents what was studied.

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