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

Not Applicable

Completed

• Conditions: Healthy
• Interventions: Device: Laser Doppler Flowmetry; Device: Goldmann applanation tonometer; Other: squatting; Device: Suction cup

• Registration Number: NCT00912665
• Lead Sponsor: Medical University of Vienna

Brief 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.

Detailed Description

Not available

Study Timeline

• Study First Submitted: 2009-06-01
• Study First Submitted QC: 2009-06-02
• Study First Posted: 2009-06-03
• Study Start: 2009-07
• Primary Completion: 2010-12
• Study Completion: 2010-12
• Status Verified: 2012-08
• Last Update Submitted: 2012-08-09
• Last Update Posted: 2012-08-10

Recruitment & Eligibility

• Status: COMPLETED
• Sex: All
• Target Recruitment: 40

Inclusion Criteria

• Men and women aged between 18 and 35 years, nonsmokers
• Men and women will be included in equal parts
• Normal findings in the medical history and physical examination unless the investigator considers an abnormality to be clinically irrelevant
• Normal findings in the laboratory testings unless the investigator considers an abnormality to be clinically irrelevant
• Normal ophthalmic findings, ametropia less than 1 diopter

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

Study & Design

• Study Type: INTERVENTIONAL
• Study Design: SINGLE_GROUP

Arm && Interventions

Group	Intervention	Description
Healthy Volunteer	Laser Doppler Flowmetry	-
Healthy Volunteer	Goldmann applanation tonometer	-
Healthy Volunteer	squatting	-
Healthy Volunteer	Suction cup	-

Primary Outcome Measures

Name	Time	Method
Optic nerve head pressure-flow relationship	in total 3x on 2 study days

Trial Locations

Locations (1)

Department of Clinical Pharmacology, Medical University of Vienna; 🇦🇹 Vienna, Austria