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Regulation of Optic Nerve Head Blood Flow During Combined Changes in Intraocular Pressure and Arterial Blood Pressure

NCT00912665 · Status: COMPLETED · Phase: NA · Type: INTERVENTIONAL · Enrollment: 40

Last updated 2012-08-10

No results posted yet for this study

Summary

Autoregulation is defined as the ability of a vascular bed to adapt its vascular resistance to changes in perfusion pressure. In the eye, several studies have reported that retinal blood flow is autoregulated over a wide range of ocular perfusion pressures. In the optic nerve head only few data are available. Large scale studies have shown that reduced ocular perfusion pressure is an important risk factor for the prevalence, the incidence and the progression of primary open angle glaucoma.

Former studies that investigated ocular blood flow autoregulation only measured choroidal blood flow. For the optic nerve head only few data are available, although it seems likely that it underlies similar autoregulatory mechanisms.

The primary goal of the present study is to gain more insight into these phenomena in humans.

The present study aims to investigate the pressure/flow relationship as a measure for optic nerve head autoregulation during combined changes of intraocular pressure and arterial pressure. Intraocular pressure will be increased by the use of a suction cup technique, mean arterial pressure will be increased by squatting. During the whole procedure, optic nerve head blood flow will be measured continuously.

Conditions

  • Healthy

Interventions

DEVICE

Laser Doppler Flowmetry

blood flow measurements at the temporal neuroretinal rim to assess optic nerve head blood flow

DEVICE

Goldmann applanation tonometer

intraocular pressure measurements

OTHER

squatting

Subjects will perform squatting for 6 minutes while either blood flow or intraocular pressure measurements

DEVICE

Suction cup

Experimental stepwise increase of intraocular pressure while either optic nerve head blood flow or intraocular pressure measurements

Sponsors & Collaborators

  • Medical University of Vienna

    lead OTHER

Study Design

Allocation
NA
Purpose
BASIC_SCIENCE
Masking
NONE
Model
SINGLE_GROUP

Eligibility

Min Age
18 Years
Max Age
35 Years
Sex
ALL
Healthy Volunteers
Yes

Timeline & Regulatory

Start
2009-07-31
Primary Completion
2010-12-31
Completion
2010-12-31

Countries

  • Austria

Study Locations

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Read the full study record

This page highlights key information. For complete eligibility criteria, study locations, investigator contacts, and the full protocol, visit the original record on ClinicalTrials.gov.

View NCT00912665 on ClinicalTrials.gov