Dopaminergic Modulation of Choroidal Blood Flow Changes During Dark/Light Transitions

This study has been completed.

Sponsor:

Information provided by:

Medical University of Vienna

ClinicalTrials.gov Identifier:

NCT00280501

First received: January 19, 2006

Last updated: July 8, 2008

Last verified: July 2008

History of Changes

Tracking Information

First Received Date ^ICMJE

January 19, 2006

Last Updated Date

July 8, 2008

Start Date ^ICMJE

August 2005

Primary Completion Date

August 2006 (final data collection date for primary outcome measure)

Current Primary Outcome Measures ^ICMJE

choroidal blood flow [ Time Frame: in total 3x 3 hours ] [ Designated as safety issue: No ]
fundus pulsation amplitude [ Time Frame: in total 3 x 3 hours ] [ Designated as safety issue: No ]

Original Primary Outcome Measures ^ICMJE

choroidal blood flow
fundus pulsation amplitude

Change History

Complete list of historical versions of study NCT00280501 on ClinicalTrials.gov Archive Site

Current Secondary Outcome Measures ^ICMJE

Not Provided

Original Secondary Outcome Measures ^ICMJE

Not Provided

Current Other Outcome Measures ^ICMJE

Not Provided

Original Other Outcome Measures ^ICMJE

Not Provided

Descriptive Information

Brief Title ^ICMJE

Dopaminergic Modulation of Choroidal Blood Flow Changes During Dark/Light Transitions

Official Title ^ICMJE

Dopaminergic Modulation of Choroidal Blood Flow Changes During Dark/Light Transitions

Brief Summary

There is evidence from a variety of animal studies that choroidal blood flow is under neural control. By contrast, only little information is available from human studies. Recent results indicate that a light/dark transition is associated with a reduction in choroidal blood flow due to an unknown mechanism. We have shown that during unilateral dark/light transitions both eyes react with choroidal vasoconstriction strongly indicating a neural mechanism responsible for the blood flow changes.

Dopamine has been discussed as a chemical messenger for light adaptation. However, dopaminergic effects in the eye are not restricted to synaptic sites of release, but dopamine also diffuses to the outer retinal layers and pigment epithelium. Accordingly, dopaminergic effects also include a modulatory role on retinal vessel diameter and animal studies provide evidence for vasodilatory effects in the choroid. There is evidence that during darkness retinal and choroidal dopamine levels decrease. Accordingly, dopamine could provide a modulatory input to the light/dark transition induced changes of choroidal circulation. The aim of the present study is to test this hypothesis.

Detailed Description

Not Provided

Study Type ^ICMJE

Interventional

Study Phase

Not Provided

Study Design ^ICMJE

Allocation: Randomized
Endpoint Classification: Safety/Efficacy Study
Intervention Model: Crossover Assignment
Masking: Double Blind (Subject, Investigator)
Primary Purpose: Treatment

Condition ^ICMJE

Regional Blood Flow
Ocular Physiology

Intervention ^ICMJE

Drug: Quetiapine (drug)
Quetiapine (Seroquel 100mg-film-coated tablet, AstraZeneca Vienna, Austria) Dose: 100 mg tablet oral single dose
Drug: Sulpiride (drug)
Sulpiride (Dogmatil 200mg-tablet, Synthélabo Groupe, Le Plessis Robinson, France) Dose: one half of 200 mg tablet oral single dose
Drug: Placebo
Placebo

Study Arm (s)

Active Comparator: 1
Quetiapine
Interventions:
- Drug: Quetiapine (drug)
- Drug: Sulpiride (drug)
- Drug: Placebo
Active Comparator: 2
Sulpiride
Interventions:
- Drug: Quetiapine (drug)
- Drug: Sulpiride (drug)
- Drug: Placebo
Placebo Comparator: 3
Placebo
Interventions:
- Drug: Quetiapine (drug)
- Drug: Sulpiride (drug)
- Drug: Placebo

Publications *

Not Provided

* Includes publications given by the data provider as well as publications identified by ClinicalTrials.gov Identifier (NCT Number) in Medline.

Recruitment Information

Recruitment Status ^ICMJE

Completed

Enrollment ^ICMJE

Completion Date

August 2006

Primary Completion Date

August 2006 (final data collection date for primary outcome measure)

Eligibility Criteria ^ICMJE

Inclusion Criteria:

Men aged between 18 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

Gender

Male

Ages

18 Years to 35 Years

Accepts Healthy Volunteers

Yes

Contacts ^ICMJE

Contact information is only displayed when the study is recruiting subjects

Location Countries ^ICMJE

Austria

Administrative Information

NCT Number ^ICMJE

NCT00280501

Other Study ID Numbers ^ICMJE

OPHT-160905

Has Data Monitoring Committee

Yes

Responsible Party

Gabriele Fuchsjaeger-Mayrl, MD, Department of Clinical Pharmacology, Medical University of Vienna

Study Sponsor ^ICMJE

Medical University of Vienna

Collaborators ^ICMJE

Not Provided

Investigators ^ICMJE

Principal Investigator:

Gabriele Fuchsjaeger-Mayrl, MD

Department of Clinical Pharmacology

Information Provided By

Medical University of Vienna

Verification Date

July 2008

^ICMJE Data element required by the International Committee of Medical Journal Editors and the World Health Organization ICTRP

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