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Vision Response to Dopamine Replacement

The safety and scientific validity of this study is the responsibility of the study sponsor and investigators. Listing a study does not mean it has been evaluated by the U.S. Federal Government. Read our disclaimer for details. Identifier: NCT01663935
Recruitment Status : Terminated (Lack of funding)
First Posted : August 14, 2012
Results First Posted : June 11, 2019
Last Update Posted : June 11, 2019
Information provided by (Responsible Party):
University of Wisconsin, Madison

Brief Summary:
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.

Condition or disease Intervention/treatment Phase
Albinism Oculocutaneous Albinism Drug: Levodopa/carbidopa Phase 2

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.

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Study Type : Interventional  (Clinical Trial)
Actual Enrollment : 20 participants
Allocation: N/A
Intervention Model: Single Group Assignment
Masking: None (Open Label)
Primary Purpose: Treatment
Official Title: Interventional Study of Levodopa Replacement on Retinal Function in Oculocutaneous Albinism
Actual Study Start Date : October 17, 2012
Actual Primary Completion Date : April 12, 2018
Actual Study Completion Date : April 12, 2018

Arm Intervention/treatment
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

Primary Outcome Measures :
  1. 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.

Other Outcome Measures:
  1. 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.

Information from the National Library of Medicine

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Ages Eligible for Study:   3 Years and older   (Child, Adult, Older Adult)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   No

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

Information from the National Library of Medicine

To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.

Please refer to this study by its identifier (NCT number): NCT01663935

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United States, Wisconsin
University of Wisconsin
Madison, Wisconsin, United States, 53705
Sponsors and Collaborators
University of Wisconsin, Madison
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Principal Investigator: Michael C Struck, MD University of Wisconsin, Madison
  Study Documents (Full-Text)

Documents provided by University of Wisconsin, Madison:
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Responsible Party: University of Wisconsin, Madison Identifier: NCT01663935    
Other Study ID Numbers: 2016-1576
2012-0023 ( Other Identifier: Study team )
First Posted: August 14, 2012    Key Record Dates
Results First Posted: June 11, 2019
Last Update Posted: June 11, 2019
Last Verified: May 2019
Keywords provided by University of Wisconsin, Madison:
oculocutaneous albinism
retina function
Additional relevant MeSH terms:
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Albinism, Oculocutaneous
Eye Diseases, Hereditary
Eye Diseases
Genetic Diseases, Inborn
Amino Acid Metabolism, Inborn Errors
Metabolism, Inborn Errors
Skin Diseases, Genetic
Pigmentation Disorders
Skin Diseases
Metabolic Diseases
Antiparkinson Agents
Anti-Dyskinesia Agents
Dopamine Agents
Neurotransmitter Agents
Molecular Mechanisms of Pharmacological Action
Physiological Effects of Drugs
Aromatic Amino Acid Decarboxylase Inhibitors
Enzyme Inhibitors