Optic Nerve Head Autoregulation During Changes in Arterial Blood Pressure

NCT01663883 | Completed DMC

• 1 other identifier: OPHT-210911
• Study Type: interventional
• Target: 40
• Locations: 1 country
• Sites: 1

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.

Conditions

Decreased Vascular Flow

Keywords

Blood flow autoregulation; optic nerve head blood flow; isometric exercise; Autoregulation; ocular physiology

Outcome Measures

Primary Outcomes (1)

• Optic nerve head blood flow

  12 minutes

Secondary Outcomes (3)

• Systolic/diastolic blood pressure

  14 minutes

• Intraocular pressure

  at baseline and minute 13

• Pulse rate

  14 minutes

Study Arms (1)

Healthy subjects

EXPERIMENTAL

Other: Isometric exercise

Interventions

Isometric exercise OTHER

use of a handgrip for 3x2 minutes

Healthy subjects

Eligibility Criteria

• Age: 18 Years - 35 Years
• Sex: all
• Healthy Volunteers: Yes
• Age Groups: Adult (18-64)

You may qualify if:

• 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

You may not qualify if:

• 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

Sponsors & Collaborators

• Medical University of Vienna: lead

Study Sites (1)

Department of Clinical Pharmacology

Vienna, Vienna, 1090, Austria

Location

MeSH Terms

Interventions

Exercise

Intervention Hierarchy (Ancestors)

Motor Activity; Movement; Musculoskeletal Physiological Phenomena; Musculoskeletal and Neural Physiological Phenomena

Study Officials

• Gerhard Garhöfer, MD

  Department of Clinical Pharmacology, Medical University of Vienna

  PRINCIPAL INVESTIGATOR

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: NA
• Masking: NONE
• Purpose: BASIC SCIENCE
• Intervention Model: SINGLE GROUP
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Ass. Prof. Priv. Doz. Dr.

Study Record Dates

• First Submitted: January 24, 2012
• First Posted: August 13, 2012
• Study Start: February 1, 2012
• Primary Completion: April 1, 2012
• Study Completion: August 1, 2012
• Last Updated: August 13, 2012

Record last verified: 2012-08

Locations

AU (1)