Neurovascular Coupling in Patients With Open Angle Glaucoma

The recruitment status of this study is unknown because the information has not been verified recently.
Verified December 2008 by Medical University of Vienna.
Recruitment status was  Recruiting
Sponsor:
Information provided by:
Medical University of Vienna
ClinicalTrials.gov Identifier:
NCT00811694
First received: July 2, 2008
Last updated: December 18, 2008
Last verified: December 2008
  Purpose

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.


Condition Intervention
Glaucoma
Other: ocular blood flow measurements

Study Type: Observational
Official Title: Neurovascular Coupling in Patients With Open Angle Glaucoma

Resource links provided by NLM:


Further study details as provided by Medical University of Vienna:

Primary Outcome Measures:
  • Retinal blood velocity (laser Doppler velocimetry) [ Time Frame: measurements done only once on the studyday ] [ Designated as safety issue: No ]
  • Retinal arterial and venous diameter (Retinal vessel analyzer) [ Time Frame: measurements done only once on the studyday ] [ Designated as safety issue: No ]
  • Optic nerve head blood flow (laser Doppler flowmetry) [ Time Frame: measurements done only once on the studyday ] [ Designated as safety issue: No ]
  • Latency and amplitude (pattern ERG) [ Time Frame: measurements done only once on the studyday ] [ Designated as safety issue: No ]

Secondary Outcome Measures:
  • Mean arterial pressure [ Time Frame: measurements done only once on the studyday ] [ Designated as safety issue: No ]

Estimated Enrollment: 60
Study Start Date: June 2004
Estimated Primary Completion Date: December 2009 (Final data collection date for primary outcome measure)
Groups/Cohorts Assigned Interventions
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

  Eligibility

Ages Eligible for Study:   18 Years to 80 Years
Genders Eligible for Study:   Both
Accepts Healthy Volunteers:   Yes
Criteria

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.
  Contacts and Locations
Choosing to participate in a study is an important personal decision. Talk with your doctor and family members or friends about deciding to join a study. To learn more about this study, you or your doctor may contact the study research staff using the Contacts provided below. For general information, see Learn About Clinical Studies.

Please refer to this study by its ClinicalTrials.gov identifier: NCT00811694

Contacts
Contact: Gerhard Garhoefer, MD 0043 1 40400 2981 gerhard.garhoefer@meduniwien.ac.at

Locations
Austria
Department of Clinical Pharmacology, Meical University of Vienna, Austria Recruiting
Vienna, Austria, 1090
Contact: Gerhard Garhofer, MD    0043 1 40400 2981    gerhard.garhoefer@meduniwien.ac.at   
Sponsors and Collaborators
Medical University of Vienna
Investigators
Principal Investigator: Gabriele Fuchsjäger Mayrl, MD Department of Clinical Pharmacology, Meical University of Vienna
  More Information

No publications provided

Responsible Party: Gabriele Fuchsjäger Mayrl, MD, Department of Clinical Pharmacology, Medical University of Vienna , Austria
ClinicalTrials.gov Identifier: NCT00811694     History of Changes
Other Study ID Numbers: OPHT-200104
Study First Received: July 2, 2008
Last Updated: December 18, 2008
Health Authority: Austria: Agency for Health and Food Safety

Keywords provided by Medical University of Vienna:
glaucoma
ficker stimulation
ocular blood flow

Additional relevant MeSH terms:
Glaucoma
Glaucoma, Open-Angle
Eye Diseases
Ocular Hypertension

ClinicalTrials.gov processed this record on October 21, 2014