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Neurovascular Coupling in Eyes of Glaucoma Patients

This study has been completed.
Sponsor:
ClinicalTrials.gov Identifier:
NCT00429819
First Posted: February 1, 2007
Last Update Posted: December 16, 2014
The safety and scientific validity of this study is the responsibility of the study sponsor and investigators. Listing a study does not mean it has been evaluated by the U.S. Federal Government. Read our disclaimer for details.
Information provided by (Responsible Party):
University Hospital, Basel, Switzerland
  Purpose

We hypothesize that glaucoma patients demonstrate an impaired retinal vascular response to the flicker stimulus, and that this disturbance is predictive of the progression of glaucomatous damage.

The response of a major temporal superior and inferior retinal artery and vein to a 60 seconds 12.5 Hz flicker light stimulation in 50 glaucoma patients, 50 ocular hypertensives and 50 controls (using the Retinal Vessel Analyzer) and to investigate how intraocular pressure relates to neurovascular coupling. In addition, 50 glaucoma patients and 50 ocular hypertension patients will be followed for 3 years for functional (visual field, automated perimetry with Octopus device) and morphological (retinal nerve fiber layer thickness, Optical Coherence Tomography Stratus (OCT) device) glaucomatous damage progression, in order to test the predictive power of the retinal vascular flicker response for glaucoma progression.


Condition
Glaucoma Ocular Hypertension

Study Type: Observational
Study Design: Observational Model: Case Control
Time Perspective: Prospective
Official Title: Neurovascular Coupling in Eyes of Glaucoma Patients

Resource links provided by NLM:


Further study details as provided by University Hospital, Basel, Switzerland:

Primary Outcome Measures:
  • Prognostic value of Flicker Response in glaucoma patients and ocular hypertension (OHT) [ Time Frame: up to 3 years ]

Enrollment: 100
Study Start Date: December 2006
Study Completion Date: December 2014
Primary Completion Date: June 2014 (Final data collection date for primary outcome measure)
Detailed Description:

Rationale: The term neurovascular coupling refers to the vascular response to an increased neuronal activity. The contact of the nerve terminals to the cortical blood vessels is mostly realized through astrocytes. A major defining property of glaucoma, cupping of the optic disc, implies tissue remodeling of the optic nerve head and involves an astrocytic responses. A malfunction of the astrocytes in glaucoma may lead not only to the hallmark of glaucoma, cupping and death of retinal ganglion cells, but also to an accompanying or even preceding disturbance in ocular neurovascular coupling. The retinal vascular bed was chosen because of the high reproducibility of the dynamic retinal vessel diameter analysis and because recently the hypoxia-inducible factor 1α was found not only in the glia of the optic nerve head but also in the retina of glaucomatous donor eyes and predominantly in retinal locations closely concordant with the locations of visual field defects recorded in these eyes, raising questions about the site of primary damage in glaucoma. It is hoped that this research project will help provide a workable tool and a model able not only to identify a risk factor for glaucoma, but in the future to explore possible therapeutic avenues to modify the course of the disease.

Working hypothesis: We hypothesize that glaucoma patients demonstrate an impaired retinal vascular response to the flicker stimulus, and that this disturbance is predictive of the progression of glaucomatous damage Subjects and Methods The present protocol intends to explore the response of a major temporal superior and inferior retinal artery and vein to a 60 seconds 12.5 Hz flicker light stimulation in 50 glaucoma patients, 50 ocular hypertensives and 50 controls (using the Retinal Vessel Analyzer) and to investigate how intraocular pressure relates to neurovascular coupling. In addition, 50 glaucoma patients and 50 ocular hypertension patients will be followed for 3 years for functional (visual field, automated perimetry with Octopus device) and morphological (retinal nerve fiber layer thickness, Optical Coherence Tomography Stratus OCT device) glaucomatous damage progression, in order to test the predictive power of the retinal vascular flicker response for glaucoma progression. Patients will be recruited in the University Eye Clinic Basel, a notification in the University Hospital of Basel and/or advertisement in a newspaper will inform potential healthy volunteers of the opportunity to participate in a scientific research project.

Study Course: Study is divided in the cross-sectional and in the cohort part. In the former, first the screening examination will be performed, to establish an eligibility of a patient / control subject for the study. Thereafter, the measurements described above will follow, which will conclude the cross-sectional part of the study. Glaucoma patients and patients with ocular hypertension will be offered a possibility to enter the cohort-study, with a 3-year follow-up embedded in the clinical routine and consisting of biannual repeated measurements outlined above.

  Eligibility

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Ages Eligible for Study:   40 Years to 79 Years   (Adult, Senior)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   No
Sampling Method:   Non-Probability Sample
Study Population
glaucoma patients ocular hypertension
Criteria

Inclusion Criteria:

  • Glaucoma
  • Ocular hypertension

Exclusion Criteria:

  • PEX or pigment dispersion syndrome
  • A history of an acute glaucoma attack
  • Chamber angle dysgenesia
  • Any form of secondary glaucoma
  • Diabetes
  • High levels of blood lipids
  • Systemic or ocular circulatory diseases
  • Medication, drugs, alcohol, smoking
  • Systolic blood pressure above 145 mmHg or a diastolic above 95 mmHg
  • Visual acuity worse than 20/25
  • High ametropia (spherical equivalent < -5 diopters or > +3 diopters)
  • Astigmatism above 2 diopters
  • Significant cataract filtering procedures
  Contacts and Locations
Information from the National Library of Medicine

To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.

Please refer to this study by its ClinicalTrials.gov identifier (NCT number): NCT00429819


Locations
Switzerland
University Eye Clinic
Basel, Basel-Stadt, Switzerland, 4031
Sponsors and Collaborators
University Hospital, Basel, Switzerland
Investigators
Study Director: Selim Orgül, MD University Eye Clinic Basel
  More Information

Responsible Party: University Hospital, Basel, Switzerland
ClinicalTrials.gov Identifier: NCT00429819     History of Changes
Other Study ID Numbers: 084-GUK-2006-002
Swiss National Foundation ( Other Grant/Funding Number: 3200B0-113685 )
First Submitted: January 31, 2007
First Posted: February 1, 2007
Last Update Posted: December 16, 2014
Last Verified: December 2014

Additional relevant MeSH terms:
Glaucoma
Ocular Hypertension
Eye Diseases