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Clinical Trial Details — Status: Completed

Administrative data

NCT number NCT00712764
Other study ID # OPHT-011206
Secondary ID
Status Completed
Phase N/A
First received July 8, 2008
Last updated July 8, 2008
Start date January 2005
Est. completion date April 2005

Study information

Verified date December 2006
Source Medical University of Vienna
Contact n/a
Is FDA regulated No
Health authority Austria: Federal Ministry for Health and Women
Study type Interventional

Clinical Trial Summary

Autoregulation is the ability of a vascular bed to maintain blood flow despite changes in perfusion pressure. For a long time it had been assumed that the choroid is a strictly passive vascular bed, which shows no autoregulation. However, recently several groups have identified some autoregulatory capacity of the human choroid. In the brain and the retina the mechanism behind autoregulation is most likely linked to changes in transmural pressure. In this model arterioles change their vascular tone depending on the pressure inside the vessel and outside the vessel. In the choroid, several observations argue against a direct involvement of arterioles. However, the mechanism behind choroidal autoregulation remains unclear. Adenosine, an endogenous purine metabolic end product with a potent vasodilatory effect on multiple vascular beds, leads to an increase in retinal and choroidal vessel diameter. The present study aims to investigate whether adenosine plays a role in choroidal autoregulation during a decrease in ocular perfusion pressure, which will be achieved by an increase in intraocular pressure.

Pressure/flow relationships will be investigated in the absence and presence of adenosine.


Recruitment information / eligibility

Status Completed
Enrollment 20
Est. completion date April 2005
Est. primary completion date April 2005
Accepts healthy volunteers Accepts Healthy Volunteers
Gender Male
Age group 18 Years to 35 Years
Eligibility Inclusion Criteria:

- Men aged between 18 and 35 years, nonsmokers

- Body mass index between 15th and 85th percentile (Must et al. 1991)

- 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 Design

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


Related Conditions & MeSH terms


Intervention

Drug:
Adenosine

Placebo


Locations

Country Name City State
Austria Department of Clinical Pharmacology, Medical University of Vienna Vienna

Sponsors (1)

Lead Sponsor Collaborator
Medical University of Vienna

Country where clinical trial is conducted

Austria, 

Outcome

Type Measure Description Time frame Safety issue
Primary choroidal pressure-flow relationship 2 hours at 2 study days No
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