Optic Nerve Head Autoregulation During Changes in Arterial Blood Pressure
- Full Text View
- Tabular View
- No Study Results Posted
- Disclaimer
- How to Read a Study Record
Purpose
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 | Intervention |
|---|---|
|
Decreased Vascular Flow |
Other: Isometric exercise |
| Study Type: | Interventional |
| Study Design: | Intervention Model: Single Group Assignment Masking: Open Label Primary Purpose: Basic Science |
- Optic nerve head blood flow [ Time Frame: 12 minutes ] [ Designated as safety issue: No ]
- Systolic/diastolic blood pressure [ Time Frame: 14 minutes ] [ Designated as safety issue: Yes ]
- Intraocular pressure [ Time Frame: at baseline and minute 13 ] [ Designated as safety issue: No ]
- Pulse rate [ Time Frame: 14 minutes ] [ Designated as safety issue: Yes ]
| Enrollment: | 40 |
| Study Start Date: | February 2012 |
| Study Completion Date: | August 2012 |
| Primary Completion Date: | April 2012 (Final data collection date for primary outcome measure) |
| Arms | Assigned Interventions |
|---|---|
| Experimental: Healthy subjects |
Other: Isometric exercise
use of a handgrip for 3x2 minutes
|
Eligibility| Ages Eligible for Study: | 18 Years to 35 Years |
| Genders Eligible for Study: | Both |
| 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| Austria | |
| Department of Clinical Pharmacology | |
| Vienna, Austria, 1090 | |
| Principal Investigator: | Gerhard Garhöfer, MD | Department of Clinical Pharmacology, Medical University of Vienna |
More Information
No publications provided
| Responsible Party: | Gerhard Garhofer, Ass. Prof. Priv. Doz. Dr., Medical University of Vienna |
| ClinicalTrials.gov Identifier: | NCT01663883 History of Changes |
| Other Study ID Numbers: | OPHT-210911 |
| Study First Received: | January 24, 2012 |
| Last Updated: | August 9, 2012 |
| Health Authority: | Austria: Agency for Health and Food Safety |
Keywords provided by Medical University of Vienna:
|
Blood flow autoregulation optic nerve head blood flow isometric exercise Autoregulation ocular physiology |
ClinicalTrials.gov processed this record on May 22, 2013