Effects of Common Topical Glaucoma Therapy on Optic Nerve Head Blood Flow Autoregulation During Increased Arterial Blood Pressure and Artificially Elevated Intraocular Pressure in Healthy Humans - Tabular View

Tracking Information

First Received Date ^ICMJE

January 11, 2006

Last Updated Date

July 8, 2008

Start Date ^ICMJE

September 2008

Estimated Primary Completion Date

December 2009 (final data collection date for primary outcome measure)

Current Primary Outcome Measures ^ICMJE

Ocular perfusion pressure - ONH blood flow relationship [ Time Frame: on 2 study days ] [ Designated as safety issue: No ]

Original Primary Outcome Measures ^ICMJE

Ocular perfusion pressure - ONH blood flow relationship

Change History

Complete list of historical versions of study NCT00275756 on ClinicalTrials.gov Archive Site

Current Secondary Outcome Measures ^ICMJE

Blood pressure, heart rate [ Time Frame: on 2 study days ] [ Designated as safety issue: Yes ]

Original Secondary Outcome Measures ^ICMJE

Same as current

Descriptive Information

Brief Title ^ICMJE

Effects of Common Topical Glaucoma Therapy on Optic Nerve Head Blood Flow Autoregulation During Increased Arterial Blood Pressure and Artificially Elevated Intraocular Pressure in Healthy Humans

Official Title ^ICMJE

Effects of Common Topical Glaucoma Therapy on Optic Nerve Head Blood Flow Autoregulation During Increased Arterial Blood Pressure and Artificially Elevated Intraocular Pressure in Healthy Humans

Brief Summary

Background

Autoregulation is the ability of a vascular bed to maintain blood flow despite changes in perfusion pressure. The existence of an effective autoregulation in the optic nerve circulation has been shown in animals and humans. The exact mechanism behind this autoregulation is still unknown. The motive for the investigation of optic nerve head (ONH) blood flow autoregulation is to enhance the understanding of pathologic eye conditions associated with ocular vascular disorders. To clarify the regulatory mechanisms of ONH microcirculation is of critical importance to understand the pathophysiology of glaucoma, because there is evidence that glaucoma is associated with optic nerve head ischemia. Several studies indicate that a disturbed autoregulation might contribute to glaucomatous optic neuropathy. Currently, five classes of intraocular pressure (IOP) reducing drugs are available for topical therapy in patients with glaucoma or elevated intraocular pressure. These drugs have also vasoactive properties, which may influence both the resting ocular circulation and the autoregulatory mechanisms of blood flow during changes in ocular perfusion pressure.

Study objective

To investigate the influence of common topical glaucoma therapy on ONH blood flow regulation during changes in IOP and systemic arterial blood pressure.

Detailed Description

Study Phase

Study Type ^ICMJE

Interventional

Study Design ^ICMJE

Basic Science, Randomized, Double Blind (Subject, Investigator), Active Control, Parallel Assignment, Safety/Efficacy Study

Condition ^ICMJE

Glaucoma
Ocular Physiology
Regional Blood Flow

Intervention ^ICMJE

Drug: Timolol (drug)
Drug: dorzolamide (drug)
Drug: brimonidine (drug)
Device: Laser Doppler flowmetry
Device: Goldmann applanation tonometer
Procedure: Suction cup method

Study Arms / Comparison Groups

Publications *

* Includes publications given by the data provider as well as publications identified by National Clinical Trials Identifier (NCT ID) in Medline.

Recruitment Information

Recruitment Status ^ICMJE

Not yet recruiting

Estimated Enrollment ^ICMJE

Estimated Completion Date

December 2009

Estimated Primary Completion Date

December 2009 (final data collection date for primary outcome measure)

Eligibility Criteria ^ICMJE

Inclusion Criteria:

Men aged between 19 and 35 years, nonsmokers
Body mass index between 15th and 85th percentile
Normal findings in the medical history and physical examination unless the investigator considers an abnormality to be clinically irrelevant
Normal ophthalmic findings, ametropia < 1 Dpt.

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
Symptoms of a clinically relevant illness in the 3 weeks before the first study day
Blood donation during the previous 3 weeks
Presence of intraocular pathology: ocular hypertension, glaucoma, retinal vasculopathy or other retinal diseases

Gender

Both

Ages

19 Years to 35 Years

Accepts Healthy Volunteers

Yes

Contacts ^ICMJE

Contact: Gerhard Garhofer, MD

+ 43 1 40400 2981

gerhard.garhoefer@meduniwien.ac.at

Location Countries ^ICMJE

Austria

Administrative Information

NCT ID ^ICMJE

NCT00275756

Responsible Party

Gabriele Fuchsjaeger-Mayrl, MD, Department of Clinical Pharmacology, Medical University of Vienna

Study ID Numbers ^ICMJE

OPHT-040106

Study Sponsor ^ICMJE

Medical University of Vienna

Collaborators ^ICMJE

Investigators ^ICMJE

Principal Investigator:

Gabriele Fuchsjaeger-Mayrl, MD

Department of Clinical Pharmacology

Information Provided By

Medical University of Vienna

Verification Date

July 2008

^ICMJE Data element required by the International Committee of Medical Journal Editors and the World Health Organization ICTRP