Optic Nerve Head Autoregulation During Changes in Arterial Blood Pressure

Not Applicable

Completed

• Conditions: Decreased Vascular Flow
• Interventions: Other: Isometric exercise

• Registration Number: NCT01663883
• Lead Sponsor: Medical University of Vienna

Brief Summary

Constant despite changes in perfusion pressure. It is observed in many vascular beds of the human body to prevent that variations in perfusion pressure are directly transmitted into changes in blood flow. This is necessary to prevent ischemia and/or hypoxia during decreased blood flow and bleeding or increased capillary pressure during increased blood flow.

In the eye, several studies have reported that retinal blood flow is autoregulated over a wide range of ocular perfusion pressures. Unfortunately only few data are available for the optic nerve head. To gain data about autoregulation is of special importance given that several important ocular diseases such as glaucoma and age-related macular degeneration are associated with impaired autoregulation. In humans most data were collected using laser Doppler flowmetry.

The present study aims to investigate the phenomenon of transient reduction in blood flow and to gain insight in the regulatory mechanisms of optic nerve head blood flow during isometric exercise.

Detailed Description

Not available

Basic Information
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Recruitment & Eligibility
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Study & Design
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Trial Locations

Study Timeline

• Study First Submitted: 2012-01-24
• Study Start: 2012-02
• Primary Completion: 2012-04
• Status Verified: 2012-08
• Study Completion: 2012-08
• Study First Submitted QC: 2012-08-09
• Last Update Submitted: 2012-08-09
• Study First Posted: 2012-08-13
• Last Update Posted: 2012-08-13

Recruitment & Eligibility

• Status: COMPLETED
• Sex: All
• Target Recruitment: 40

Inclusion Criteria

• Men and women aged between 18 and 35 years, nonsmokers
• Normal findings in the medical history and physical examination unless the investigator considers an abnormality to be clinically irrelevant
• Normal ophthalmic findings, ametropia less than 3 diopters

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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 (except oral contraceptives)
• Symptoms of a clinically relevant illness in the 3 weeks before the first study day
• Blood donation during the previous 3 weeks

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Study & Design

• Study Type: INTERVENTIONAL
• Study Design: SINGLE_GROUP

Arm && Interventions

Group	Intervention	Description
Healthy subjects	Isometric exercise	-

Primary Outcome Measures

Name	Time	Method
Optic nerve head blood flow	12 minutes

Secondary Outcome Measures

Name	Time	Method
Pulse rate	14 minutes
Intraocular pressure	at baseline and minute 13
Systolic/diastolic blood pressure	14 minutes

Trial Locations

Locations (1)

Department of Clinical Pharmacology; 🇦🇹 Vienna, Austria