Optic Nerve Head Autoregulation During Changes in Arterial Blood Pressure

Status

Completed

Phases

Study type

Interventional

Source

ClinicalTrials.gov

Registry ID

NCT01663883

Enrollment

Registered

2012-08-13

Start date

2012-02-29

Completion date

2012-08-31

Last updated

2012-08-13

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Decreased Vascular Flow

Keywords

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

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.

Interventions

OTHERIsometric exercise

use of a handgrip for 3x2 minutes

Study design

Allocation

Intervention model

SINGLE_GROUP

Primary purpose

BASIC_SCIENCE

Masking

NONE

Eligibility

Sex/Gender

ALL

Age

18 Years to 35 Years

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

Design outcomes

Primary

Measure	Time frame
Optic nerve head blood flow	12 minutes

Secondary

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

Countries

Austria

Outcome results

None listed

Source: ClinicalTrials.gov · Data processed: Feb 4, 2026