Effect of Cosopt Versus Combigan on Retinal Vascular Autoregulation in Primary Open Angle Glaucoma (POAG)

March 31, 2017 updated by: Louis Pasquale, MD, Massachusetts Eye and Ear Infirmary

We have completed a study in which we examined the response of the retinal circulation to changes in posture from sitting to lying down in patients with primary open angle glaucoma (POAG). This alteration in position produces changes in the local blood pressure at the entrance to the retinal vasculature. In a healthy retina, the vasculature adapts by dilating and constricting in order to maintain a steady blood flow rate. In an eye with POAG, this often does not occur. As a result, there are large fluctuations in blood flow which may produce the retinal neuronal damage associated with glaucoma.

The purpose of this study is to demonstrate that topical anti-glaucoma treatments with agents that have vasoactive as well as IOP-lowering effects can have a beneficial effect on maintaining a steady retinal blood flow rate even when there are changes in local blood pressure.

Study Overview

Status

Completed

Conditions

Intervention / Treatment

Study Type

Interventional

Enrollment (Actual)

21

Phase

  • Not Applicable

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
        • Massachusetts Eye and Ear Infirmary

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

40 years to 80 years (Adult, Older Adult)

Accepts Healthy Volunteers

No

Genders Eligible for Study

All

Description

Inclusion Criteria:

  • POAG
  • Age 40 to 80 years
  • Untreated IOP greater than 21 mm Hg

Exclusion Criteria:

  • More than two IOP lowering medications
  • Exfoliation or pigment dispersion syndrome
  • Diabetic retinopathy
  • History of ocular surgery

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: Basic Science
  • Allocation: Randomized
  • Interventional Model: Single Group Assignment
  • Masking: Quadruple

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Experimental: Brimonidine 0.2%-timolol 0.5% arm
Patients using timolol were switched to brimonidine tartrate / timolol maleate 0.2%/05% 1 get BID OU for six weeks.
Drug: Brimonidine 0.2%-0.5% timolol 0.5
BID OU for 6 weeks
Other Names:
  • Combigan
  • RVD intervention after run-in on timolol 0.5% bid OU
Active Comparator: Dorzolamide 2%-timolol 0.5% arm
Patients using timolol were switched ti dorzolamide hydrochloride / timolol 0.5% 2%/0.5% bid OU for six weeks
Drug: Dorzolamide 2%-timolol 0.5%
BID OU for 6 weeks
Other Names:
  • Cosopt
  • RVD intervention after run-in on timolol 0.5% bid OU

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Presence of Retinal Vascular Dysregulation (RVD)
Time Frame: 6 weeks post treatment
We determined whether RVD was present in the following way. The difference between the retinal blood flow measured while reclining for 30 minutes and the baseline retinal blood flow measured while seated was calculated. In a previous study, we found that among healthy subjects the change in the blood flow while reclining compared to baseline was +6.5% ± 12%. For this study, we defined the normal range of blood flow autoregulation as ± 2 standard deviations about the mean percentage change found in the control group in the initial study (6.5% ± 24.0%); that is, as -17.5% to +30.5%. Participants with a change in retinal blood flow induced by posture change outside this range were randomized to either dorzolamide-timolol fixed combination BID OU or brimonidine-timolol fixed combination BID OU for 6 weeks.
6 weeks post treatment

Collaborators and Investigators

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

Sponsor

Massachusetts Eye and Ear Infirmary

Investigators

  • Principal Investigator: Louis Pasquale, Mass Eye and Ear Infirmary

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

General Publications

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

January 1, 2009

Primary Completion (Actual)

August 1, 2012

Study Completion (Actual)

August 1, 2012

Study Registration Dates

First Submitted

January 16, 2009

First Submitted That Met QC Criteria

January 16, 2009

First Posted (Estimate)

January 19, 2009

Study Record Updates

Last Update Posted (Actual)

April 4, 2017

Last Update Submitted That Met QC Criteria

March 31, 2017

Last Verified

March 1, 2017

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • 08-12-057

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

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.

Clinical Trials on Glaucoma

Clinical Trials on Brimonidine 0.2%-0.5% timolol 0.5

Search Similar Trials

Sponsors and Collaborators

Medical Conditions

Drug Interventions

CROs by country

CROs in Belarus

Conditions

Rare Diseases

Drug Interventions

Dietary Supplements

Sponsor/Collaborators

Locations

Subscribe