Retinal Blood Flow and Microthrombi in Type 1 Diabetes

October 28, 2015 updated by: Schepens Eye Research Institute

The project aims to find mechanisms for the abnormal retinal blood flow that in diabetic patients often precedes any evidence of clinical retinopathy and may contribute to the development of retinopathy.

Specifically, the projects tests the hypothesis that reduced retinal blood flow found in young patients with type 1 diabetes reflects increased resistance in the small vessels of the retina caused by the formation of small blood clots, called microthrombi; and that antiplatelet agents normalize the reduced retinal blood flow.

Study Overview

Status

Completed

Conditions

Intervention / Treatment

Detailed Description

The ultimate goal of this research is to contribute to the development of strategies to prevent diabetic retinopathy. This project will test the hypothesis that antiplatelet agents normalize the reduced blood flow observed early in the course of type 1 diabetes. If the hypothesis is proven correct, the results will indicate that the formation of small blood clots (microthrombi) occurs early in diabetic retinal vessels. In turn, because microthrombosis could readily account for the occlusive microangiopathy that causes the sight-threatening stages of diabetic retinopathy, the results will propose the desirability of antiplatelet therapy for the prevention of diabetic retinopathy.

We have three specific aims:

  1. To confirm that, under basal conditions, retinal blood flow measured with the laser Doppler method in a group of type 1 diabetic patients with no or minimal retinopathy differs from the flow measured in age- and sex-matched nondiabetic control subjects;
  2. To determine whether the response of retinal blood flow to low-dose aspirin (81 mg/day) administered for 2 months versus placebo, differs between type 1 diabetic patients with no or minimal retinopathy and age- and sex-matched nondiabetic control subjects;
  3. To determine whether in type 1 diabetic patients with no or minimal retinopathy the response of retinal blood flow to low-dose aspirin differs from the response to clopidogrel, a drug that interferes with platelet function downstream of the site of aspirin action.

Study Type

Interventional

Enrollment

100

Phase

  • Phase 2

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Locations

  • United States
    • Massachusetts
      • Boston, Massachusetts, United States, 02114
        • Schepens Eye Research Institute

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

18 years to 45 years (Adult)

Accepts Healthy Volunteers

No

Genders Eligible for Study

All

Description

Inclusion Criteria:

  • Age 18-45 years,
  • type 1 diabetes duration 1-15 years,
  • absent or minimal retinopathy (EDTRS 20).
  • Age- and gender-matched healthy controls

Exclusion Criteria:

  • smoking,
  • systemic diseases other than diabetes,
  • retinal diseases other than diabetic retinopathy,
  • pregnancy,
  • bleeding disorders,
  • aspirin allergy,
  • use of anti-platelet agents,
  • non-steroidal anti-inflammatory agents,
  • angiotensin converting enzyme inhibitors,
  • angiotensin receptor antagonists,
  • Vitamin E in large doses.

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Diagnostic
  • Allocation: Randomized
  • Interventional Model: Parallel Assignment
  • Masking: Double

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Retinal blood flow

Secondary Outcome Measures

Outcome Measure
Retinal arterial blood speed
Retinal arterial diameter

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Schepens Eye Research Institute

Investigators

  • Principal Investigator: Mara Lorenzi, MD, Schepens Eye Research Institute

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start

June 1, 2003

Primary Completion

December 7, 2022

Study Completion

March 1, 2006

Study Registration Dates

First Submitted

November 30, 2006

First Submitted That Met QC Criteria

December 1, 2006

First Posted (Estimate)

December 4, 2006

Study Record Updates

Last Update Posted (Estimate)

October 30, 2015

Last Update Submitted That Met QC Criteria

October 28, 2015

Last Verified

March 1, 2006

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • 2002-015
  • 2003P-000224
  • EY014812

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

product manufactured in and exported from the U.S.

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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