Optic Nerve Head Autoregulation During Changes in Arterial Blood Pressure

• Sponsor: Medical University of Vienna (Other)
• Overall Status: Completed
• CT.gov ID: NCT01663883
• Collaborator: (none)
• Enrollment: 40
• Location: 1
• Arm: 1
• Duration (Months): 6
• Patients Per Site Per Month: 6.7

Study Details

Study Description

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.

Condition or Disease	Intervention/Treatment	Phase
Decreased Vascular Flow	Other: Isometric exercise	N/A

Study Design

• Study Type: Interventional
• Actual Enrollment: 40 participants
• Allocation: N/A
• Intervention Model: Single Group Assignment
• Masking: None (Open Label)
• Primary Purpose: Basic Science
• Study Start Date: Feb 1, 2012
• Actual Primary Completion Date: Apr 1, 2012
• Actual Study Completion Date: Aug 1, 2012

Arms and Interventions

Arm	Intervention/Treatment
Experimental: Healthy subjects	Other: Isometric exercise; use of a handgrip for 3x2 minutes

Outcome Measures

Primary Outcome Measures

1. Optic nerve head blood flow [12 minutes]

Secondary Outcome Measures

1. Systolic/diastolic blood pressure [14 minutes]

2. Intraocular pressure [at baseline and minute 13]

3. Pulse rate [14 minutes]

Eligibility Criteria

Criteria

• Ages Eligible for Study: 18 Years to 35 Years
• Sexes Eligible for Study: All
• Accepts Healthy Volunteers: Yes

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

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

Contacts and Locations

Locations

	Site	City	State	Country	Postal Code
1	Department of Clinical Pharmacology	Vienna		Austria	1090

Sponsors and Collaborators

• Medical University of Vienna

Investigators

• Principal Investigator: Gerhard Garhöfer, MD, Department of Clinical Pharmacology, Medical University of Vienna

Study Documents (Full-Text)

None provided.

More Information

Publications

None provided.

• Responsible Party: Gerhard Garhofer, Ass. Prof. Priv. Doz. Dr., Medical University of Vienna
• ClinicalTrials.gov Identifier: NCT01663883
• Other Study ID Numbers: OPHT-210911
• First Posted: Aug 13, 2012
• Last Update Posted: Aug 13, 2012
• Last Verified: Aug 1, 2012

• Keywords provided by Gerhard Garhofer, Ass. Prof. Priv. Doz. Dr., Medical University of Vienna: Blood flow autoregulation; optic nerve head blood flow; isometric exercise; Autoregulation; ocular physiology

Study Results

No Results Posted as of Aug 13, 2012