The Effect of Dopamine on Diabetic Retinopathy
Condition: Diabetes
MeSH terms: Diabetic Retinopathy
Study type: Interventional
Phase: Phase 1

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.
    

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.
    

Intervention name(s): Low Dose Sinemet CR; High Dose Sinemet CR; RETeval Electroretinogram (ERG) Testing; Contrast Sensitivity Testing; Visual Acuity Testing
Intervention type(s): Drug; Drug; Device; Other; Other
Intervention description(s): Sinemet CR (25 mg carbidopa/100 mg levodopa) will be taken by mouth twice daily for two weeks.; Sinemet CR (50 mg carbidopa/200 mg levodopa) will be taken by mouth twice daily for two weeks.; 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.; 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.; 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.
Intervention MeSH terms: Carbidopa, levodopa drug combination; Carbidopa; Levodopa
Allocation: Randomized
Intervention model: Parallel Assignment
Masking: Double (Participant, Investigator)
Primary purpose: Treatment
Keywords: Ophthalmology