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Sponsored by: |
Medical University of Vienna |
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Information provided by: | Medical University of Vienna |
ClinicalTrials.gov Identifier: | NCT00915070 |
Autoregulation is defined as the ability of a vascular bed to adapt its vascular resistance to changes in perfusion pressure. In the eye, several studies have reported that retinal blood flow is autoregulated over a wide range of ocular perfusion pressures. The investigators could recently show that Endothelin-1 is a key metabolite in the regulation of vascular tone in the eye and plays an important role in the blood flow autoregulation of the choroidal circulation. However, no data is yet available for the optic nerve head. Thus, the present study is designed to test the hypothesis that Endothelin-1 plays also a role in optic nerve head blood flow autoregulation.
Therefore, subjects will perform squatting to increase systemic perfusion pressure during administration of either an endothelin A-receptor blocker (BQ-123) or placebo. Optic nerve head blood flow will be continuously measured during the procedure to investigate optic nerve head autoregulation.
Condition | Intervention |
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Healthy |
Drug: BQ-123 Drug: Physiological saline solution Device: Laser Doppler Flowmetry Device: Goldmann Applanation Tonometer Other: squatting |
Study Type: | Interventional |
Study Design: | Basic Science, Randomized, Double Blind (Subject, Investigator, Outcomes Assessor), Placebo Control, Crossover Assignment, Safety/Efficacy Study |
Official Title: | Role of Endothelin-1 in Optic Nerve Head Blood Flow Regulation During Isometric Exercise in Healthy Humans |
Estimated Enrollment: | 24 |
Study Start Date: | July 2009 |
Estimated Primary Completion Date: | July 2010 (Final data collection date for primary outcome measure) |
Arms | Assigned Interventions |
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BQ-123: Active Comparator |
Drug: BQ-123
60 mcg/min, infusion period: 60 min
Drug: Physiological saline solution
infusion period 60 minutes
Device: Laser Doppler Flowmetry
blood flow measurements at the temporal neuroretinal rim to assess optic nerve head blood flow
Device: Goldmann Applanation Tonometer
intraocular pressure measurements
Other: squatting
subjects will perform squatting for 6 minutes while blood flow measurements
|
Physiological saline solution: Placebo Comparator |
Drug: BQ-123
60 mcg/min, infusion period: 60 min
Drug: Physiological saline solution
infusion period 60 minutes
Device: Laser Doppler Flowmetry
blood flow measurements at the temporal neuroretinal rim to assess optic nerve head blood flow
Device: Goldmann Applanation Tonometer
intraocular pressure measurements
Other: squatting
subjects will perform squatting for 6 minutes while blood flow measurements
|
Ages Eligible for Study: | 18 Years to 35 Years |
Genders Eligible for Study: | Both |
Accepts Healthy Volunteers: | Yes |
Inclusion Criteria:
Exclusion Criteria:
Contact: Gerhard Garhoefer, MD, Priv-Doz. | 0043 1 40400 ext 2981 | gerhard.garhoefer@meduniwien.ac.at |
Austria | |
Department of Clinical Pharmacology, Medical University of Vienna | |
Vienna, Austria, 1090 |
Principal Investigator: | Gabriele Fuchsjaeger-Mayrl, MD, Univ.Doz | Department of Clinical Pharmacology, Medical University of Vienna |
Responsible Party: | Department of Clinical Pharmacology, Medical University of Vienna ( Gabriele Fuchsjaeger-Mayrl, MD ) |
Study ID Numbers: | OPHT-320708 |
Study First Received: | June 1, 2009 |
Last Updated: | June 4, 2009 |
ClinicalTrials.gov Identifier: | NCT00915070 History of Changes |
Health Authority: | Austria: Agency for Health and Food Safety |
BQ-123 Optic Nerve Head Blood Flow Intraocular Pressure |
Regional Blood Flow Ocular Physiology Optic Disk |
Cyclo(Trp-Asp-Pro-Val-Leu) Healthy |