MedDataX Logo

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

NCT ID: NCT00280501

Last Updated: 2008-07-09

Study Results

Results pending

The study team has not published outcome measurements, participant flow, or safety data for this trial yet. Check back later for updates.

Basic Information

Get a concise snapshot of the trial, including recruitment status, study phase, enrollment targets, and key timeline milestones.

Recruitment Status

COMPLETED

Clinical Phase

NA

Total Enrollment

21 participants

Study Classification

INTERVENTIONAL

Study Start Date

2005-08-31

Study Completion Date

2006-08-31

Brief Summary

Review the sponsor-provided synopsis that highlights what the study is about and why it is being conducted.

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

Dive into the extended narrative that explains the scientific background, objectives, and procedures in greater depth.

Conditions

See the medical conditions and disease areas that this research is targeting or investigating.

Regional Blood Flow Ocular Physiology

Keywords

Explore important study keywords that can help with search, categorization, and topic discovery.

Sulpiride Quetiapine Light/dark transition Choroidal blood flow

Study Design

Understand how the trial is structured, including allocation methods, masking strategies, primary purpose, and other design elements.

Allocation Method

RANDOMIZED

Intervention Model

CROSSOVER

Primary Study Purpose

TREATMENT

Blinding Strategy

DOUBLE

Participants Investigators

Study Groups

Review each arm or cohort in the study, along with the interventions and objectives associated with them.

1

Quetiapine

Group Type ACTIVE_COMPARATOR

Quetiapine (drug)

Intervention Type DRUG

Quetiapine (Seroquel 100mg-film-coated tablet, AstraZeneca Vienna, Austria) Dose: 100 mg tablet oral single dose

Sulpiride (drug)

Intervention Type DRUG

Sulpiride (Dogmatil 200mg-tablet, Synthélabo Groupe, Le Plessis Robinson, France) Dose: one half of 200 mg tablet oral single dose

Placebo

Intervention Type DRUG

Placebo

2

Sulpiride

Group Type ACTIVE_COMPARATOR

Quetiapine (drug)

Intervention Type DRUG

Quetiapine (Seroquel 100mg-film-coated tablet, AstraZeneca Vienna, Austria) Dose: 100 mg tablet oral single dose

Sulpiride (drug)

Intervention Type DRUG

Sulpiride (Dogmatil 200mg-tablet, Synthélabo Groupe, Le Plessis Robinson, France) Dose: one half of 200 mg tablet oral single dose

Placebo

Intervention Type DRUG

Placebo

3

Placebo

Group Type PLACEBO_COMPARATOR

Quetiapine (drug)

Intervention Type DRUG

Quetiapine (Seroquel 100mg-film-coated tablet, AstraZeneca Vienna, Austria) Dose: 100 mg tablet oral single dose

Sulpiride (drug)

Intervention Type DRUG

Sulpiride (Dogmatil 200mg-tablet, Synthélabo Groupe, Le Plessis Robinson, France) Dose: one half of 200 mg tablet oral single dose

Placebo

Intervention Type DRUG

Placebo

Interventions

Learn about the drugs, procedures, or behavioral strategies being tested and how they are applied within this trial.

Quetiapine (drug)

Quetiapine (Seroquel 100mg-film-coated tablet, AstraZeneca Vienna, Austria) Dose: 100 mg tablet oral single dose

Intervention Type DRUG

Sulpiride (drug)

Sulpiride (Dogmatil 200mg-tablet, Synthélabo Groupe, Le Plessis Robinson, France) Dose: one half of 200 mg tablet oral single dose

Intervention Type DRUG

Placebo

Placebo

Intervention Type DRUG

Eligibility Criteria

Check the participation requirements, including inclusion and exclusion rules, age limits, and whether healthy volunteers are accepted.

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
Minimum Eligible Age

18 Years

Maximum Eligible Age

35 Years

Eligible Sex

MALE

Accepts Healthy Volunteers

Yes

Sponsors

Meet the organizations funding or collaborating on the study and learn about their roles.

Medical University of Vienna

OTHER

Sponsor Role lead

Responsible Party

Identify the individual or organization who holds primary responsibility for the study information submitted to regulators.

Department of Clinical Pharmacology, Medical University of Vienna

Principal Investigators

Learn about the lead researchers overseeing the trial and their institutional affiliations.

Gabriele Fuchsjaeger-Mayrl, MD

Role: PRINCIPAL_INVESTIGATOR

Department of Clinical Pharmacology

Locations

Explore where the study is taking place and check the recruitment status at each participating site.

Department of Clinical Pharmacology

Vienna, , Austria

Site Status

Countries

Review the countries where the study has at least one active or historical site.

Austria

Other Identifiers

Review additional registry numbers or institutional identifiers associated with this trial.

OPHT-160905

Identifier Type: -

Identifier Source: org_study_id