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

Mass Eye and Ear

Status: Completed

Conditions: Glaucoma

Treatments: Drug: Dorzolamide 2%-timolol 0.5%; Drug: Brimonidine 0.2%-0.5% timolol 0.5

Study type: Interventional

Funder types: Other

Identifiers

NCT00824824

08-12-057

Details and patient eligibility

About

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.

Enrollment: 21 patients

Sex: All

Ages: 40 to 80 years old

Volunteers: No Healthy Volunteers

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

Trial design

Primary purpose: Basic Science

Allocation: Randomized

Interventional model: Single Group Assignment

Masking: Quadruple Blind

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21 participants in 2 patient groups

Brimonidine 0.2%-timolol 0.5% arm

Experimental group

Description:

Patients using timolol were switched to brimonidine tartrate / timolol maleate 0.2%/05% 1 get BID OU for six weeks.

Treatment:

Drug: Brimonidine 0.2%-0.5% timolol 0.5

Dorzolamide 2%-timolol 0.5% arm

Active Comparator group

Description:

Patients using timolol were switched ti dorzolamide hydrochloride / timolol 0.5% 2%/0.5% bid OU for six weeks

Treatment:

Drug: Dorzolamide 2%-timolol 0.5%