Neurovascular Coupling in Patients With Early Stage Diabetes Retinopathy

July 19, 2012 updated by: Gerhard Garhofer

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.

Study Overview

Status

Completed

Conditions

Intervention / Treatment

Study Type

Observational

Enrollment (Actual)

100

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, Medical University of Vienna

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

20 years to 50 years (Adult)

Accepts Healthy Volunteers

Yes

Genders Eligible for Study

All

Sampling Method

Non-Probability Sample

Study Population

50 Patients with Diabetes Type 1 50 Healthy Control Subjects

Description

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

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?

Design Details

Cohorts and Interventions

Group / Cohort
Intervention / Treatment
2
Healthy control subjects
Other: Ocular blood flow measurements
non-invasive haemodynamic measurements of retinal vessel diameters and laser Doppler velocimetry
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

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Time Frame
Intraocular pressure
Time Frame: 90 minutes
90 minutes
Retinal arterial and venous diameter
Time Frame: 90 minutes
90 minutes
Retinal blood velocity
Time Frame: 90 minutes
90 minutes
Pattern ERG
Time Frame: measured once on the study day
measured once on the study day

Secondary Outcome Measures

Outcome Measure
Time Frame
Mean arterial pressure
Time Frame: 90 minutes
90 minutes
Blood glucose
Time Frame: measured once on the study day
measured once on the study day

Collaborators and Investigators

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

Sponsor

Gerhard Garhofer

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

General Publications

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

January 1, 2007

Primary Completion (Actual)

September 1, 2011

Study Completion (Actual)

December 1, 2011

Study Registration Dates

First Submitted

July 7, 2008

First Submitted That Met QC Criteria

July 7, 2008

First Posted (Estimate)

July 10, 2008

Study Record Updates

Last Update Posted (Estimate)

July 20, 2012

Last Update Submitted That Met QC Criteria

July 19, 2012

Last Verified

July 1, 2012

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • OPHT-221203

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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