Neurovascular Coupling in Patients With Open Angle Glaucoma

November 20, 2014 updated by: Medical University of Vienna

A variety of studies demonstrate that ocular blood flow is altered in glaucoma. Various animal and human studies have shown an increase in retinal and optic nerve head blood flow in response to diffuse luminance flicker. Based on studies with ERG, this effect has been attributed to augmented activity in the retinal ganglion cells and associated axons indicating a coupling mechanism between neuronal activity and retinal blood flow. Whereas a variety of studies have confirmed these effects, the knowledge about this coupling in the retina of patients with glaucoma is sparse.

Recently the investigators could show that flicker induced vasodilatation is blunted in patients with open angle glaucoma. However, the investigators results are limited by the fact that only data about retinal vessel diameters, not blood flow per se, are available. The further development of the investigators current flicker stimulation technique now allows us to determine blood flow velocity during flicker stimulation. Thus, in the current study, the investigators set out to determine whether this blood flow response is impaired in patients with glaucoma as compared to those in healthy volunteers and whether this is related to altered neural activity.

The study objective was, to investigate whether the blood flow response to flicker stimulation is altered in patients with glaucoma.

Study Overview

Status

Terminated

Conditions

Intervention / Treatment

Study Type

Observational

Enrollment (Anticipated)

15

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Locations

  • Austria
      • Vienna, Austria, 1090
        • Department of Clinical Pharmacology, Meical University of Vienna, Austria

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

18 years to 80 years (Adult, Older Adult)

Accepts Healthy Volunteers

Yes

Genders Eligible for Study

All

Description

Inclusion Criteria:

  • Men and women aged between 20 and 80 years.
  • Normal findings in the medical history and physical examination unless the investigator considers an abnormality to be clinically irrelevant.
  • Inclusion criteria of patients are open angle glaucoma.
  • Men and women will be included in equal parts. A pregnancy test will be performed at screening.
  • Ametropia of less than 3 diopters and anisometropia of less than 1 diopter.

Exclusion Criteria:

  • Treatment with vasoactive drugs.
  • Presence of intraocular pathology other than open angle glaucoma.
  • Presence of ocular hypertension or PEX (pseudoexfoliation) glaucoma
  • History or family history of epilepsy.
  • Pregnancy.
  • Diabetes mellitus.

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Cohorts and Interventions

Group / Cohort
Intervention / Treatment
a
15 male and 15 female patients with glaucoma
Other: ocular blood flow measurements
non-invasive haemodynamic measurements of retinal vessel diameters, laser Doppler flowmetry and laser Doppler velocimetry
b
30 sex matched healthy volunteers
Other: ocular blood flow measurements
non-invasive haemodynamic measurements of retinal vessel diameters, laser Doppler flowmetry and laser Doppler velocimetry

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Time Frame
Retinal blood velocity (laser Doppler velocimetry)
Time Frame: measurements done only once on the studyday
measurements done only once on the studyday
Retinal arterial and venous diameter (Retinal vessel analyzer)
Time Frame: measurements done only once on the studyday
measurements done only once on the studyday
Optic nerve head blood flow (laser Doppler flowmetry)
Time Frame: measurements done only once on the studyday
measurements done only once on the studyday
Latency and amplitude (pattern ERG)
Time Frame: measurements done only once on the studyday
measurements done only once on the studyday

Secondary Outcome Measures

Outcome Measure
Time Frame
Mean arterial pressure
Time Frame: measurements done only once on the studyday
measurements done only once on the studyday

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Medical University of Vienna

Investigators

  • Principal Investigator: Gabriele Fuchsjäger Mayrl, MD, Department of Clinical Pharmacology, Meical University of Vienna

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start

October 1, 2006

Primary Completion (Actual)

April 1, 2007

Study Completion (Actual)

May 1, 2012

Study Registration Dates

First Submitted

July 2, 2008

First Submitted That Met QC Criteria

December 18, 2008

First Posted (Estimate)

December 19, 2008

Study Record Updates

Last Update Posted (Estimate)

November 21, 2014

Last Update Submitted That Met QC Criteria

November 20, 2014

Last Verified

November 1, 2014

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • OPHT-200104

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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