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

NCT00824824 | Completed Results

• 1 other identifier: 08-12-057
• Study Type: interventional
• Target: 21
• Locations: 1 country
• Sites: 1

Brief Summary

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.

Conditions

Glaucoma

Keywords

Retinal Vascular Autoregulation

Outcome Measures

Primary Outcomes (1)

• Presence of Retinal Vascular Dysregulation (RVD)

  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

Study Arms (2)

Brimonidine 0.2%-timolol 0.5% arm

EXPERIMENTAL

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

Dorzolamide 2%-timolol 0.5% arm

ACTIVE COMPARATOR

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%

Interventions

Dorzolamide 2%-timolol 0.5% DRUG

BID OU for 6 weeks

Also known as: Cosopt, RVD intervention after run-in on timolol 0.5% bid OU

Dorzolamide 2%-timolol 0.5% arm

Brimonidine 0.2%-0.5% timolol 0.5 DRUG

BID OU for 6 weeks

Also known as: Combigan, RVD intervention after run-in on timolol 0.5% bid OU

Brimonidine 0.2%-timolol 0.5% arm

Eligibility Criteria

• Age: 40 Years - 80 Years
• Sex: all
• Healthy Volunteers: No
• Age Groups: Adult (18-64), Older Adult (65+)

You may qualify if:

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

You may not qualify if:

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

Sponsors & Collaborators

• Massachusetts Eye and Ear Infirmary: lead

Study Sites (1)

Massachusetts Eye and Ear Infirmary

Boston, Massachusetts, 02114, United States

Location

Related Publications (1)

• Feke GT, Pasquale LR. Retinal blood flow response to posture change in glaucoma patients compared with healthy subjects. Ophthalmology. 2008 Feb;115(2):246-52. doi: 10.1016/j.ophtha.2007.04.055. Epub 2007 Aug 8.

  PMID: 17689612 BACKGROUND

MeSH Terms

Conditions

Glaucoma

Interventions

dorzolamide; dorzolamide-timolol combination; Brimonidine Tartrate; Brimonidine Tartrate, Timolol Maleate Drug Combination

Condition Hierarchy (Ancestors)

Ocular Hypertension; Eye Diseases

Intervention Hierarchy (Ancestors)

Quinoxalines; Heterocyclic Compounds, 2-Ring; Heterocyclic Compounds, Fused-Ring; Heterocyclic Compounds; Timolol; Propanolamines; Amino Alcohols; Alcohols; Organic Chemicals; Propanols; Amines; Thiadiazoles; Thiazoles; Sulfur Compounds; Azoles; Heterocyclic Compounds, 1-Ring; Drug Combinations; Pharmaceutical Preparations

Limitations and Caveats

A potential limitation of this study is that no washout period occurred because the 6-week treatment periods extended beyond the typical 2-week washout period for dorzolamide and the 3-week washout period for brimonidine.

Results Point of Contact

• Title: Louis R. Pasquale, MD
• Organization: Massachusetts Eye and Ear Infirmary

Louis_Pasquale@meei.harvard.edu

617-573-4270

Study Officials

• Louis Pasquale

  Mass Eye and Ear Infirmary

  PRINCIPAL INVESTIGATOR

Publication Agreements

• PI is Sponsor Employee: No
• Restrictive Agreement: No

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: RANDOMIZED
• Masking: QUADRUPLE
• Who Masked: PARTICIPANT, CARE PROVIDER, INVESTIGATOR, OUTCOMES ASSESSOR
• Purpose: BASIC SCIENCE
• Intervention Model: SINGLE GROUP
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Director, Glaucoma Service Associate Director, Telemedicine

Study Record Dates

• First Submitted: January 16, 2009
• First Posted: January 19, 2009
• Study Start: January 1, 2009
• Primary Completion: August 1, 2012
• Study Completion: August 1, 2012
• Last Updated: April 4, 2017
• Results First Posted: October 28, 2016

Record last verified: 2017-03

Data Sharing

• IPD Sharing: Will not share

Locations

US (1)