Clinical trial NCT00811694: Neurovascular Coupling in Patients With Open Angle Glaucoma
Official title: Neurovascular Coupling in Patients With Open Angle Glaucoma
Study type: OBSERVATIONAL
Overall status: TERMINATED
Conditions: Glaucoma
Keywords: glaucoma
ficker stimulation
ocular blood flow
Lead sponsor: Medical University of Vienna
Sponsor class: OTHER
First posted: 2008-12-19
Enrollment: 15
Sex: ALL
Minimum age (years): 18
Maximum age (years): 80
Standard ages: ADULT
OLDER_ADULT
Accepts healthy volunteers: yes

Brief summary: 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.


Eligibility 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.

Primary outcomes:
measure: Retinal blood velocity (laser Doppler velocimetry)
timeFrame: measurements done only once on the studyday
measure: Retinal arterial and venous diameter (Retinal vessel analyzer)
timeFrame: measurements done only once on the studyday
measure: Optic nerve head blood flow (laser Doppler flowmetry)
timeFrame: measurements done only once on the studyday
measure: Latency and amplitude (pattern ERG)
timeFrame: measurements done only once on the studyday
Secondary outcomes:
measure: Mean arterial pressure
timeFrame: measurements done only once on the studyday
Other outcomes:
Locations:
city: Vienna
country: Austria
facility: Department of Clinical Pharmacology, Meical University of Vienna, Austria
Study officials:
affiliation: Department of Clinical Pharmacology, Meical University of Vienna
name: Gabriele Fuchsjäger Mayrl, MD
role: PRINCIPAL_INVESTIGATOR
References: