The Relationship Between Stage of Diabetic Retinopathy and Retinal Blood Flow in Patients With IDDM During Euglycemic Clamp

The Relationship Between Stage of Diabetic Retinopathy and Retinal Blood Flow in Patients With IDDM During Euglycemic Clamp

Sponsors

Lead Sponsor: Medical University of Vienna

Source Medical University of Vienna
Brief Summary

Impaired retinal blood flow has been implicated in the pathogenesis of diabetic retinopathy. Patel et al. (1992) showed that retinal blood flow increases with the level of diabetic retinopathy. Grunwald et al. (1996) reported that patients with insulin dependent diabetes mellitus (IDDM) of relatively short duration have increased retinal blood flow, even before the onset of diabetic retinopathy. On the other hand the data of Bursell et al. (1996) indicate that IDDM patients have reduced retinal blood flow, when they have normal blood glucose levels, but this study may have considerable methodological limitations. Acute elevations of blood glucose levels, however, result in an increase in retinal blood flow (Grunwald et al. 1987, Bursell et al. 1996). Based on previous experimental data the investigators hypothesize that ocular blood flow is increased in early diabetes and reduced at later stages of the disease. Previous studies have demonstrated that metabolic conditions such as hyperglycemia influence outcome parameters and thereby might have confounded results regarding ocular blood flow in diabetic retinopathy. The investigators will therefore study patients with IDDM during euglycemic conditions.

Overall Status Completed
Start Date March 1999
Completion Date December 2003
Primary Completion Date April 2000
Phase Phase 2
Study Type Interventional
Primary Outcome
Measure Time Frame
retinal blood flow after 1 hour of insulin clamp 2 x 2 minutes
Secondary Outcome
Measure Time Frame
Mean blood velocities in ophthalmic artery, posterior ciliary arteries and central retinal artery after 1 hour of insulin clamp 2 x 10 minutes
Enrollment 64
Condition
Intervention

Intervention Type: Drug

Intervention Name: Insulin

Description: Insulin Dosage form : intravenous infusion, infusion period 60 minutes Dosage: continuous dose of 0.5 mU/kg/min infused intravenously over 60 min; Insulin Lilly, Huminsulin, Lilly, Fegersheim, France

Intervention Type: Drug

Intervention Name: Glucose

Description: Glucose: Dosage form : intravenous infusion, infusion period 60 minutes per dose level Dosage: at a rate to maintain blood glucose level at 100mg ; 20mg/100ml Glucose

Eligibility

Criteria:

Inclusion Criteria:

Patients with IDDM:

- Age >= 19 years

- Best corrected visual acuity >= 0.8

- Ametropia < 6 dpt

Healthy control subjects:

- Age and sex matched to the subjects in the patients group

- Best corrected visual acuity >= 0.8

- Ametropia < 6 dpt

Exclusion Criteria:

Any of the following will exclude a diabetic patient from the study:

- Presence of intraocular pathology other than diabetic retinopathy (for example: cataract, glaucoma, ocular hypertension)

- Hypertension (Systolic blood pressure > 160 mm Hg or diastolic blood pressure > 90 mm Hg)

- Previous laser photocoagulation treatment

- Pregnancy (in women)

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

- Regular use of medication, abuse of alcoholic beverages, participation in a clinical trial in the 3 weeks preceding the study

- Treatment in the previous 3 weeks with any drug

- Symptoms of a clinically relevant illness in the 3 weeks before the first study day

- History or presence of gastrointestinal, liver or kidney disease, or other conditions known to interfere with distribution, metabolism or excretion of study drugs

- Blood donation during the previous 3 weeks

- Pregnancy (in women)

Gender: All

Minimum Age: 19 Years

Maximum Age: N/A

Healthy Volunteers: Accepts Healthy Volunteers

Overall Official
Last Name Role Affiliation
Hans-Georg Eichler, MD Principal Investigator Department of Clinical Pharmacology, Medical University of Vienna
Location
Facility: Department of Clinical Pharmacology, Medical University of Vienna
Location Countries

Austria

Verification Date

December 2008

Responsible Party

Name Title: Hans-Georg Eichler, MD

Organization: Department of Clinical Pharmacology, Medical University of Vienna

Has Expanded Access No
Condition Browse
Study Design Info

Allocation: Non-Randomized

Intervention Model: Parallel Assignment

Primary Purpose: Diagnostic

Masking: None (Open Label)

Source: ClinicalTrials.gov