Coupling of Neural Activity and Retinal Blood Flow in Diabetes

The recruitment status of this study is unknown because the information has not been verified recently.
Verified April 2011 by Medical University of Vienna.
Recruitment status was  Not yet recruiting
Sponsor:
Information provided by:
Medical University of Vienna
ClinicalTrials.gov Identifier:
NCT01375166
First received: April 11, 2011
Last updated: June 15, 2011
Last verified: April 2011
  Purpose

The prevalence of diabetes is increasing and the management of the disease is nowadays considered a major challenge. Affected patients have increased mortality and morbidity as well as a significant drop in the quality of life. The complications of diabetes can be classified as microvascular (e.g. nephropathy, neuropathy or retinopathy) or macrovascular (e.g. cardiovascular or cerebrovascular).

Several large-scale epidemiologic studies indicating that wider retinal venous caliber is strongly associated with the fasting glucose level as well as with diabetes. Another retinal vascular abnormality that is associated with diabetes is an abnormal retinal vascular response to flicker stimulation. Retinal vessel dilatation in response to stimulation with diffuse flicker light occurs due to a phenomenon called neurovascular coupling. This means that increased activity of neurons is associated with an increased retinal metabolism. This leads to a release of endogenous vasodilator substances and increased blood flow. However, previous studies were limited by the fact that retinal vessel diameters and blood flow were not measured simultaneously.

The present study aims to investigate whether the response of retinal vessel diameters and blood flow velocities to flicker stimulation is altered in patients with diabetes. Both parameters will be measured in real time using Fourier Domain Doppler OCT.


Condition
Diabetic Retinopathy

Study Type: Observational
Study Design: Observational Model: Case Control
Time Perspective: Prospective

Resource links provided by NLM:


Further study details as provided by Medical University of Vienna:

Primary Outcome Measures:
  • Retinal vessel diameters [ Time Frame: 18 months ] [ Designated as safety issue: No ]
  • Retinal blood flow velocities [ Time Frame: 18 months ] [ Designated as safety issue: No ]

Estimated Enrollment: 48
Study Start Date: August 2011
Estimated Primary Completion Date: February 2013 (Final data collection date for primary outcome measure)
Groups/Cohorts
Diabetic retinopathy
Patients with early insulin dependent diabetes and no or mild non-proliferative retinopathy
healthy
healthy control subjects

  Eligibility

Ages Eligible for Study:   18 Years and older
Genders Eligible for Study:   Both
Accepts Healthy Volunteers:   Yes
Sampling Method:   Non-Probability Sample
Study Population

24 patients with early insulin dependent diabetes and no or mild non-proliferative retinopathy, non-smokers 24 age and sex matched healthy controls, non-smokers

Criteria

Inclusion Criteria:

  • Men and women aged over 18 years, nonsmokers
  • Normal findings in the medical history (except diabetes) and physical examination unless the investigator considers an abnormality to be clinically irrelevant
  • normal laboratory findings (except diabetes associated parameters) unless the investigator considers the abnormality to be clinically irrelevant
  • normal ophthalmic findings (except mild diabetic retinopathy), Ametropia less than 6 diopters
  • inclusion criterion of patients is type I diabetes with non or mild non-proliferative retinopathy

Exclusion criteria

Any of the following will exclude a healthy subject from the study:

  • Regular use of vasoactive drugs
  • Abuse of alcoholic beverages, participation in a clinical trial in the 3 weeks preceding the study
  • Symptoms of a clinically relevant illness in the 3 weeks before the first study day
  • Blood donation during the previous 3 weeks
  • History or presence of any ocular pathology
  • History or family history of epilepsy
  • Systemic hypertension defined as systolic blood pressure >150mmHg, diastolic blood pressure >90mmHg
  • Pregnancy

Any of the following will exclude a subject with diabetes from the study:

  • Presence of non-insulin dependent diabetes, maturity onset diabetes of the young (MODY diabetes)
  • History or presence of any other diabetes induced vascular pathologies or any other ocular condition other then diabetic retinopathy
  • Best corrected visual acuity <0.8
  • Previous laser photocoagulation treatment
  • Systemic hypertension defined as systolic blood pressure >150mmHg, diastolic blood pressure >90mmHg
  • History or family history of epilepsy
  • Abuse of alcoholic beverages, participation in a clinical trial in the 3 weeks preceding the study
  • Symptoms of a clinically relevant illness in the 3 weeks before the first study day
  • Blood donation during the previous 3 weeks
  • 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: NCT01375166

Contacts
Contact: Gerhard Garhöfer, MD 0043 1 40400 ext 2981 gerhard.garhoefer@meduniwien.ac.at

Locations
Austria
Department of Clinical Pharmacology Not yet recruiting
Vienna, Austria, 1090
Sponsors and Collaborators
Medical University of Vienna
Investigators
Principal Investigator: Gerhard Garhöfer, MD Department of Clinical Pharmacology, Medical University of Vienna
  More Information

No publications provided

Responsible Party: Gerhard Garhöfer, MD, Department of Clinical Pharmacology, Medical University of Vienna
ClinicalTrials.gov Identifier: NCT01375166     History of Changes
Other Study ID Numbers: OPHT-070111
Study First Received: April 11, 2011
Last Updated: June 15, 2011
Health Authority: Austria: Agengy for Health and food Safety

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

ClinicalTrials.gov processed this record on September 18, 2014