The Retinal Function in Relation to Glucose Changes

This project has the following specific purposes:

• To develop a clinically usable test to determine the blood glucose level or HbA1c-level, to which the retina is adapted. This will be performed by means of ERG implicit time measurements in relation to the blood glucose level during an oral glucose tolerance test (OGTT) and inter- or extrapolation to the level of blood glucose (or HbA1c) where implicit time is normal.
• To examine darkadaptation in diabetics in relation to changes in the glucose level.
• To examine vessel diameter changes in diabetic individuals when changing the glucose level transiently

Study Overview

• Status: Unknown
• Conditions: Diabetes
• Intervention / Treatment: Other: Glucose test

Detailed Description

Study 1: 24 type 2 diabetics with minimal diabetic retinopathy but varying HbA1c level.

Study 2: 24 type 2 diabetics with minimal diabetic retinopathy. Study 3: 24 type 2 diabetics with minimal diabetic retinopathy.

Plan of trial:

Study 1: Test individuals will be examined at baseline: Prior history of illness, eye examination, blood test, fundusphoto and fullfield-ERG. Afterwards test individuals will take an oral glucose tolerance test (OGTT) which results in a peak in blood glucose after approx. 2 hours, whereafter the blood glucose level normalizes. Immediately after the sugar intake test individuals will be examined by repeated fullfield-ERG's and blood glucose measurements (every 30 min) until the blood glucose level has been normalized.

Study 2: Test individuals will be examined at baseline: Prior history of illness, eye examination, blood test, fundusphoto and dark adaptation. Afterwards test individuals will take an oral glucose tolerance test (OGTT) which results in a peak in blood glucose after approx. 2 hours, whereafter the blood glucose level normalizes. 80 minutes after the sugar intake test individuals will be examined by repeated dark adaptation and blood glucose measurements.

Study 3: Test individuals will be examined at baseline: Prior history of illness, eye examination, blood test, fundusphoto. Afterwards test individuals will take an oral glucose tolerance test (OGTT) which results in a peak in blood glucose after approx. 2 hours, whereafter the blood glucose level normalizes. At baseline (fasting) and 80 minutes after the sugar intake test individuals will be examined by redfree photos of optic disc and blood glucose measurements.

• Study Type: Interventional
• Enrollment (Anticipated): 80
• Phase: Not Applicable

Contacts and Locations

Study Locations

• Denmark
  • Glostrup, Denmark, 2600
    • Recruiting
    • Glostrup Hospital
    • Contact: Stig Holfort, Medical doctor; Phone Number: +45 43234817
    • Principal Investigator: Stig Holfort, medical doctor

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years to 80 years (Adult, Older Adult)
• Accepts Healthy Volunteers: No
• Genders Eligible for Study: All

Description

Inclusion Criteria:

• Type 2 diabetic individuals. Age > 17 < 80
• Dysregulated type 1 diabetic individuals and newly diagnosed type 1 diabetics. Age >17 < 60 years
• with minimal or no diabetic retinopathy defined by no more than five microaneurysms or dot hemorrhages per eye on three non-stereoscopic 50 degree color fundus photographs

Exclusion Criteria:

• Test individuals with significant cataract, prior surgery to the eye, diabetic retinopathy, other serious eye disease, hypertension, other serious systemic disease.

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Basic Science
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: Single

Number of Arms

1

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Other: Glucose; Subjects are given an oral glucose tolerance test.	Other: Glucose test; Subjects ingest an oral glucose tolerance test.; Other Names: Standardized oral glucose tolereance test (75 g glucose)

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Time Frame
Changes in amplitude/implicit times, changes in dark adaptation, changes in vessel caliber, changes in Optical coherence tomography (OCT)	1 day

Collaborators and Investigators

• Sponsor: Glostrup University Hospital, Copenhagen
• Investigators: Principal Investigator: Stig Holfort, Medical Doctor, Glostrup University Hospital, Copenhagen

Study record dates

Study Major Dates

• Study Start: September 1, 2009
• Primary Completion (Anticipated): October 1, 2009
• Study Completion (Anticipated): October 1, 2009

Study Registration Dates

• First Submitted: September 8, 2009
• First Submitted That Met QC Criteria: September 8, 2009
• First Posted (Estimate): September 9, 2009

Study Record Updates

• Last Update Posted (Estimate): September 24, 2009
• Last Update Submitted That Met QC Criteria: September 23, 2009
• Last Verified: September 1, 2009

More Information

Terms related to this study

• Other Study ID Numbers: Stig Holfort