Effect of Levodopa on Human Multifocal Electroretinogram

December 19, 2008 updated by: Medical University of Vienna
It is known that dopamine is a functional neuromodulator at several levels of the visual system. Dopamine seems to be involved in the organization of the ganglion cell and the bipolar cell receptive fields and modulation of physiological activity of photoreceptors. There is evidence for the functional significance of dopaminergic modulation of visual sensitivity in humans which confirms the hypothesis that dopamine plays an important role in retinal light adaptation as well as in motion and contrast sensitivity function. The electrophysiological effects of dopamine, various dopamine antagonist and levodopa in animals and humans have been investigated by means of visual evoked potentials and electroretinograms. The multifocal ERG technique, developed by Sutter et al. allows a rapid, simultaneous recording of focal ERGs from multiple retinal locations. Although this technique is relatively new, it has already provided insights into the mechanisms of retinal diseases (e.g. involvement of visual system in Parkinson disease), but until now there is no data on influence of dopaminergic substances on mERG.

Study Overview

Status

Completed

Conditions

Intervention / Treatment

Study Type

Interventional

Enrollment (Actual)

20

Phase

  • Phase 4

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

  • Austria
      • Vienna, Austria, 1090
        • Department of Clinical Pharmacology, Medical University of Vienna

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

19 years to 35 years (Adult)

Accepts Healthy Volunteers

Yes

Genders Eligible for Study

Male

Description

Inclusion Criteria:

  • Men aged between 19 and 35 years, nonsmokers
  • Body mass index between 15th and 85th percentile
  • Normal findings in the medical history and physical examination unless the investigator considers an abnormality to be clinically irrelevant
  • Normal laboratory values unless the investigator considers an abnormality to be clinically irrelevant
  • Normal ophthalmic findings, ametropia < 3 Dpt

Exclusion Criteria:

  • Regular use of medication, abuse of alcoholic beverages, participation in a clinical trial in the 3 weeks preceding the study
  • Treatment in the previous 3 weeks with any drug
  • Symptoms of a clinically relevant illness in the 3 weeks before the first study day
  • History of hypersensitivity to the trial drug or to drugs with a similar chemical structure
  • History or presence of gastrointestinal, liver or kidney disease, or other conditions known to interfere with, distribution, metabolism or excretion of study drugs
  • Blood donation during the previous 3 weeks

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: Randomized
  • Interventional Model: Crossover Assignment
  • Masking: Triple

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Experimental: 1
Drug: levodopa
1 tablet of 200 mg levodopa plus 50 mg benserazide
Other Names:
  • Madopar

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Time Frame
Retinal activity (mERG amplitude)
Time Frame: 5 measurements on both study days
5 measurements on both study days

Secondary Outcome Measures

Outcome Measure
Time Frame
Retinal activity (mERG latency)
Time Frame: 5 measurements on both study days
5 measurements on both study days
Dopamine and levodopa plasma levels
Time Frame: on both study days
on both study days

Collaborators and Investigators

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

Sponsor

Medical University of Vienna

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

October 1, 2001

Primary Completion (Actual)

October 1, 2003

Study Completion (Actual)

October 1, 2003

Study Registration Dates

First Submitted

December 18, 2008

First Submitted That Met QC Criteria

December 19, 2008

First Posted (Estimate)

December 22, 2008

Study Record Updates

Last Update Posted (Estimate)

December 22, 2008

Last Update Submitted That Met QC Criteria

December 19, 2008

Last Verified

December 1, 2008

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • OPHT-220501

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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