Neurovascular Coupling in Patients With Early Stage Diabetes Retinopathy

This study has been completed.
Sponsor:
Information provided by (Responsible Party):
Gerhard Garhofer, Medical University of Vienna
ClinicalTrials.gov Identifier:
NCT00712842
First received: July 7, 2008
Last updated: July 19, 2012
Last verified: July 2012
  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

Study Type: Observational
Study Design: Observational Model: Cohort
Time Perspective: Prospective
Official Title: Neurovascular Coupling in Patients With Early Stage Diabetes Retinopathy

Resource links provided by NLM:


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 ]

Enrollment: 100
Study Start Date: January 2007
Study Completion Date: December 2011
Primary Completion Date: September 2011 (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
Sampling Method:   Non-Probability Sample
Study Population

50 Patients with Diabetes Type 1 50 Healthy Control Subjects

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
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: NCT00712842

Locations
Austria
Department of Clinical Pharmacology, Medical University of Vienna
Vienna, Austria, 1090
Sponsors and Collaborators
Gerhard Garhofer
  More Information

No publications provided by Medical University of Vienna

Additional publications automatically indexed to this study by ClinicalTrials.gov Identifier (NCT Number):
Responsible Party: Gerhard Garhofer, MD, Medical University of Vienna
ClinicalTrials.gov Identifier: NCT00712842     History of Changes
Other Study ID Numbers: OPHT-221203
Study First Received: July 7, 2008
Last Updated: July 19, 2012
Health Authority: Austria: Agency for Health and Food Safety

Keywords provided by Medical University of Vienna:
Diabetes
ocular blood flow

Additional relevant MeSH terms:
Retinal Diseases
Diabetic Retinopathy
Eye Diseases
Diabetic Angiopathies
Vascular Diseases
Cardiovascular Diseases
Diabetes Complications
Diabetes Mellitus
Endocrine System Diseases

ClinicalTrials.gov processed this record on October 19, 2014