A Comparison of the Effect of Dorzolamide and Timolol on Optic Disk Blood Flow in Patients With Open Angle Glaucoma

Phase 2

Completed

• Conditions: Glaucoma, Open-Angle
• Interventions: Drug: Dorzolamide 2%; Drug: Timolol 0.5%

• Registration Number: NCT00991822
• Lead Sponsor: Medical University of Vienna

Brief Summary

Glaucoma is one of the most common causes of blindness in the industrialized nations. For a long time glaucoma has been defined as a disease in which high intraocular pressure (IOP) leads to irreversible optic disk damage and concommitant visual field loss. However, recent investigations show that IOP is not necessarily an adequate measure of clinical severity or a predictor of clinical progression: about 20% of all eyes with high IOP do not develop visual field loss and some patients suffering from visual field loss due to optic disk damage have normal IOP. Hence, factors other than IOP are likely involved in the pathogenesis of glaucoma. The role of vascular factors in the pathogenesis of glaucoma has recently received much attention and optic nerve head hypoperfusion may play a critical role in the development of glaucoma. It may therefore be important for an optimal prevention of visual field defects in glaucoma that the topical antiglaucoma drugs used do not only reduce IOP but also stabilize or enhance the perfusion of the optic nerve head.

Therefore, the aim of the present study is to compare the effect of a 3 months treatment with timolol or dorzolamide in patients with open angle glaucoma on optic disk blood flow.

Detailed Description

Not available

Study Timeline

• Study Start: 1999-05
• Primary Completion: 2001-12
• Study Completion: 2003-12
• Status Verified: 2009-10
• Study First Submitted: 2009-10-07
• Study First Submitted QC: 2009-10-07
• Last Update Submitted: 2009-10-07
• Study First Posted: 2009-10-08
• Last Update Posted: 2009-10-08

Recruitment & Eligibility

• Status: COMPLETED
• Sex: All
• Target Recruitment: 160

Inclusion Criteria

• Men and women older than 19 years
• Primary open angle glaucoma or ocular hypertension with IOP higher than 22 mmHg in at least one eye
• Washout period for previous antiglaucoma treatment: two weeks for adrenergic agonists, one week for parasympathomimetic agents

Exclusion Criteria

• Exfoliation glaucoma, pigmentary glaucoma
• History of acute angle closure
• Intraocular surgery or argon laser trabeculoplasty within the last 6 months
• Ocular inflammation or infection within the last 3 months
• Contact lenses
• Patients with bradycardia (heart rate less than 50 beats/min)
• Second or third degree heart block
• Asthma
• COPD
• Congestive Heart Failure
• Severe renal impairment (Creatinine clearance less than 1.8 l/h
• History or hypersensitivity to one of the study drugs or drugs with similar chemical structure
• History of non-IOP responder to beta-blockers or carbonic anhydrase inhibitors
• Pregnancy

Study & Design

• Study Type: INTERVENTIONAL
• Study Design: PARALLEL

Arm && Interventions

Group	Intervention	Description
1	Dorzolamide 2%	Patients with open angle glaucoma
2	Timolol 0.5%	Patients with open angle glaucoma

Primary Outcome Measures

Name	Time	Method
Percent change over baseline after 3 months of treatment of optic disk blood flow measured with the Heidelberg Retina Flowmeter	5 minutes measurement of optic disk blood flow on 3 study days
Percent change over baseline after 3 months of treatment of fundus pulsation amplitude (FPA) in the optic disk as assessed with laser interferometry	5 minutes measurement of FPA on 3 study days

Trial Locations

Locations (1)

Department of Clinical Pharmacology, Medical University of Vienna; 🇦🇹 Vienna, Austria