Neurovascular Coupling in Patients With Early Stage Diabetes Retinopathy - Full Text View

Sponsored by:	Medical University of Vienna
Information provided by:	Medical University of Vienna
ClinicalTrials.gov Identifier:	NCT00712842

Purpose

A variety of studies demonstrate that ocular blood flow is altered in diabetes and retinal perfusion abnormalities have been proposed to contribute to the pathogenesis of diabetic retinopathy.

Various animal and human studies have demonstrated that retinal and optic nerve blood flow increase 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 describe the effects of flickering light on retinal and optic nerve head blood flow, the knowledge about this coupling in the diabetic retina is sparse.

In view of the fact that neural activity and blood flow are strongly coupled in the human retina, one could hypothesize that neurodegenerative changes in the retina could contribute to the vascular dysregulation and in turn lead to changes of ocular perfusion. The investigators set out to investigate whether the coupling of neural activity and blood flow is impaired in patients with early stage diabetic retinopathy compared to those in healthy volunteers.

Condition	Intervention
Diabetic Retinopathy	Other: Ocular blood flow measurements

MedlinePlus related topics: Diabetes Diabetic Eye Problems Retinal Disorders

U.S. FDA Resources

Study Type:	Observational
Official Title:	Neurovascular Coupling in Patients With Early Stage Diabetes Retinopathy

Further study details as provided by Medical University of Vienna:

Primary Outcome Measures:

Intraocular pressure [ Time Frame: 90 minutes ] [ Designated as safety issue: No ]
Retinal arterial and venous diameter [ Time Frame: 90 minutes ] [ Designated as safety issue: No ]
Retinal blood velocity [ Time Frame: 90 minutes ] [ Designated as safety issue: No ]
Pattern ERG [ Time Frame: measured once on the study day ] [ Designated as safety issue: No ]

Secondary Outcome Measures:

Mean arterial pressure [ Time Frame: 90 minutes ] [ Designated as safety issue: Yes ]
Blood glucose [ Time Frame: measured once on the study day ] [ Designated as safety issue: Yes ]

Estimated Enrollment:	100
Study Start Date:	January 2007
Estimated Study Completion Date:	October 2009
Estimated Primary Completion Date:	October 2009 (Final data collection date for primary outcome measure)

Groups/Cohorts	Assigned Interventions
1 Patients with non or mild non-proliferative diabetic retinopathy	Other: Ocular blood flow measurements non-invasive haemodynamic measurements of retinal vessel diameters and laser Doppler velocimetry
2 Healthy control subjects	Other: Ocular blood flow measurements non-invasive haemodynamic measurements of retinal vessel diameters and laser Doppler velocimetry

Eligibility

Ages Eligible for Study:	20 Years to 50 Years
Genders Eligible for Study:	Both
Accepts Healthy Volunteers:	Yes

Criteria

Inclusion Criteria:

Men and women aged between 20 and 50 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 insulin dependent diabetes mellitus (IDDM) with non or mild non-proliferative retinopathy. Patients with no signs of diabetic retinopathy (level 1) or patients with one or more microaneurysms (level 2) will be included. Duration of Diabetes is between 5 and 20 years
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:

Non insulin dependent diabetes
Maturity onset diabetes of the young (MODY diabetes)
Any sign of non diabetes induced vascular pathologies, systemic hypertension (defined as systolic blood pressure > 150 mm Hg and diastolic blood pressure > 90 mm Hg.)
Presence of intraocular pathology other than diabetic retinopathy
History or family history of epilepsy
Pregnancy

Contacts and Locations

Please refer to this study by its ClinicalTrials.gov identifier: NCT00712842

Contacts

Contact: Gerhard Garhofer, MD

0043140400 ext 2981

klin-pharmakologie@meduniwien.ac.at

Locations

Austria
Department of Clinical Pharmacology, Medical University of Vienna	Recruiting
Vienna, Austria, 1090

Sponsors and Collaborators

Medical University of Vienna

More Information

Responsible Party:	Department of Clinical Pharmacology ( Gabriele Fuchsjaeger-Mayrl )
Study ID Numbers:	OPHT-221203
Study First Received:	July 7, 2008
Last Updated:	December 19, 2008
ClinicalTrials.gov Identifier:	NCT00712842
Health Authority:	Austria: Agency for Health and Food Safety

Keywords provided by Medical University of Vienna:

Diabetes
ocular blood flow

Study placed in the following topic categories:

Diabetic Retinopathy
Eye Diseases
Vascular Diseases
Diabetes Mellitus
Endocrine System Diseases

Endocrinopathy
Diabetes Complications
Retinal Diseases
Diabetic Angiopathies

Additional relevant MeSH terms:

Cardiovascular Diseases

ClinicalTrials.gov processed this record on January 14, 2009