MedTrace Logo

Brain Dopamine Biomarker

NCT07748715 · Status: NOT_YET_RECRUITING · Type: OBSERVATIONAL · Enrollment: 50

Last updated 2026-08-12

No results posted yet for this study

Summary

This study is being conducted at the Morsani College of Medicine to determine whether signals recorded from the eyes and brain can be used as a noninvasive way to monitor dopamine function. Approximately 50 adults (25 with Parkinson's disease and 25 without Parkinson's disease) will participate. Participants will undergo electroretinography (ERG) and electroencephalography (EEG), which are FDA-approved, noninvasive devices that measure electrical activity from the retina and brain using sensors placed on the skin around the eyes and scalp. Participants with Parkinson's disease will be tested before and after taking their prescribed Parkinson's medication (e.g., Sinemet® \[carbidopa/levodopa\]). Participants without Parkinson's disease will receive a single dose of compounded levodopa/carbidopa eye drops (an FDA-approved drug used in an unapproved ophthalmic formulation) in one eye and a placebo eye drop in the other eye. The placebo consists of the same vehicle solution without levodopa/carbidopa and contains 0.1% ascorbic acid, 0.001% benzalkonium chloride, and phosphate-buffered saline. Randomization will be used to determine which eye receives the levodopa/carbidopa eye drop and which eye receives the placebo. Researchers will compare measurements obtained before and after treatment to evaluate whether blue-light visual responses are associated with dopamine activity.

Conditions

  • Parkinson Disease
  • Healthy Adult Participants

Interventions

DRUG

Levadopa/Carbidopa eyedrops

Topical levodopa/carbidopa eyedrops (1.4/0.34 microM) in a base of 0.1% w/v ascorbic acid and 0.001% w/v benzalkonium chloride dissolved in 1× phosphate-buffered saline.

OTHER

Sham

The vehicle (control) solution will consist of 0.1% w/v ascorbic acid and 0.001% w/v benzalkonium chloride dissolved in 1× phosphate-buffered saline.

DRUG

Levodopa/Carbidopa (Sinemet)

Parkinson's patients will self-administer their medication and measurements will be taken prior to and 15-30 minutes after self-administration.

Sponsors & Collaborators

  • Center for Neuromusculoskeletal Research

    collaborator UNKNOWN

  • University of South Florida

    lead OTHER

Principal Investigators

  • Nathan D Schilaty, DC, PhD · University of South Florida

Eligibility

Min Age
18 Years
Sex
ALL
Healthy Volunteers
Yes

Timeline & Regulatory

Start
2026-10-01
Primary Completion
2027-09-30
Completion
2027-09-30
FDA Drug
Yes

More Related Trials

Read the full study record

This page highlights key information. For complete eligibility criteria, study locations, investigator contacts, and the full protocol, visit the original record on ClinicalTrials.gov.

View NCT07748715 on ClinicalTrials.gov