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Completed

NCT Number: NCT00712842

Neurovascular Coupling in Patients With Early Stage Diabetes Retinopathy

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.

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Key information

Conditions

Diabetic Retinopathy Cardiovascular Diseases Diabetes Complications Diabetes Mellitus Diabetic Angiopathies Endocrine System Diseases Eye Diseases Glucose Metabolism Disorders Metabolic Diseases Nutritional and Metabolic Diseases Retinal Diseases Vascular Diseases

Age range

20 year–50 year

Sex eligibility

All sexes

Study type

Observational

Primary location

Department of Clinical Pharmacology, Medical University of Vienna

Vienna, State of Vienna, 1090, Austria

Who can participate

Healthy volunteers accepted: Yes

Only the study team can determine whether someone qualifies for participation.

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

Treatment and study plan

Ocular blood flow measurements

Other

non-invasive haemodynamic measurements of retinal vessel diameters and laser Doppler velocimetry

Primary outcomes

  1. Intraocular pressure

    Time frame: 90 minutes

  2. Retinal arterial and venous diameter

    Time frame: 90 minutes

  3. Retinal blood velocity

    Time frame: 90 minutes

  4. Pattern ERG

    Time frame: measured once on the study day

Secondary outcomes

  1. Mean arterial pressure

    Time frame: 90 minutes

  2. Blood glucose

    Time frame: measured once on the study day

Sponsors and collaborators

Lead sponsor

Gerhard Garhofer

Other

Registry information

Important dates

Study start
2007
Primary completion
2011
Study completion
2011
First posted
Jul 10, 2008
Registry last updated
Jul 20, 2012

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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