Vision Response to Dopamine Replacement

May 17, 2019 updated by: University of Wisconsin, Madison

Interventional Study of Levodopa Replacement on Retinal Function in Oculocutaneous Albinism

The purpose of the study is to evaluate and document physiologic and functional changes in visual performance and retinal function of patients diagnosed with albinism (a dopamine deficiency state) following a trial of oral Levodopa/carbidopa treatment.

Study Overview

Status

Terminated

Conditions

Intervention / Treatment

Detailed Description

In this study the investigators propose that the retina itself in albinism is deficient in dopamine, and vision improvement will occur as a result of improved retinal function in response to the deficient neurotransmitter dopamine. This study has a pretest-posttest design in order to determine if improvement in vision is in response to replacement of deficiency (dopamine). The electroretinography (ERG) testing and optical coherence tomography (OCT) will be critical determinants to confirm vision improvement as a result of improved retinal function, but are not primary outcome data. Main outcome measures will be collected at pre-treatment, 1 month, 3 months, and 4 months. Change in visual acuity as measured in logMAR by Snellen or sweep visual evoked potential (SVEP) after 3 months of treatment is the primary outcome. Patients include OCA1a patients, OCA1b, OCA2, and unclassified Oculocutaneous albinism (OCA). OCA1a patients clinically are known to have the worst vision, and physiologically have the lowest (or absent) levels of tyrosinase function (Dopamine Production). All patients will be treated with Levodopa/carbidopa 4mg/kg/day in three divided doses.

Study Type

Interventional

Enrollment (Actual)

20

Phase

  • Phase 2

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Locations

  • United States
    • Wisconsin
      • Madison, Wisconsin, United States, 53705
        • University of Wisconsin

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

3 years and older (ADULT, OLDER_ADULT, CHILD)

Accepts Healthy Volunteers

No

Genders Eligible for Study

All

Description

Inclusion Criteria:

  • clinical diagnosis of oculocutaneous albinism
  • age over 3 and weight over 25 lbs.

Exclusion Criteria:

  • ocular only albinism
  • ocular pathology other than albinism
  • neurologic disease, history of myocardial infarction, history of clinical depression, pregnancy

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: TREATMENT
  • Allocation: NA
  • Interventional Model: SINGLE_GROUP
  • Masking: NONE

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
OTHER: Levodopa/carbidopa 4mg/kg/day
Treatment drug taken orally three times daily
Drug: Levodopa/carbidopa
This study will have an intent to treat goal. Anyone that fits the inclusion criteria for the study will be entered and receive study drug.
Other Names:
  • Sinemet
  • Atamet
  • Parcopa

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Visual Acuity Change
Time Frame: 3 months
Change in visual acuity from baseline to 3 months as measured in logMAR by Snellen or Sweep visual evoked potential (SVEP). logMar lower values equals better visual outcome.
3 months

Other Outcome Measures

Outcome Measure
Measure Description
Time Frame
Contrast Sensitivity
Time Frame: 3 months
Ancillary testing of visual/retinal function with contrast sensitivity testing. Contrast sensitivity testing measures how well the eyes can distinguish between finer and finer light increments compared to dark. This test is a chart with different capital letters organized in horizontal lines. The contrast decreases with each line. The person will move down the chart to determine the least level of contrast they can see.
3 months

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

University of Wisconsin, Madison

Investigators

  • Principal Investigator: Michael C Struck, MD, University of Wisconsin, Madison

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (ACTUAL)

October 17, 2012

Primary Completion (ACTUAL)

April 12, 2018

Study Completion (ACTUAL)

April 12, 2018

Study Registration Dates

First Submitted

August 9, 2012

First Submitted That Met QC Criteria

August 13, 2012

First Posted (ESTIMATE)

August 14, 2012

Study Record Updates

Last Update Posted (ACTUAL)

June 11, 2019

Last Update Submitted That Met QC Criteria

May 17, 2019

Last Verified

May 1, 2019

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • 2016-1576
  • 2012-0023 (OTHER: Study team)

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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