Effect of Xalacom® (Latanoprost/Timolol) and Combigan® (Brimonidine/Timolol) Fixed Combination on Intraocular Pressure and Ocular Blood Flow in Patients With Primary Open Angle Glaucoma or Ocular Hypertension

Study Overview
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Brief Summary
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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 disc damage and subsequent visual field loss. However, recent investigations show that IOP is not the only factor that is involved in the glaucomatous process leading to retinal ganglion cell death. The role of vascular factors in the pathogenesis of glaucoma has recently received much attention based on animal experiments and epidemiological studies. The main focus of glaucoma is still directed towards a decrease in IOP. There is, however, also considerable interest whether antiglaucoma drugs influence ocular perfusion. Although measurement of ocular blood flow is still difficult, a number of innovative techniques have been realized which cover different aspects of ocular perfusion. In the present study Xalacom® (latanoprost/timolol) and the fixed combination of Combigan® (brimonidine/timolol) will be compared with respect to their IOP lowering efficacy as well as their ocular hemodynamic effects.

Official Title
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A Double-masked Randomized Cross-over Study Comparing of the Effect of Xalacom® (Latanoprost/Timolol)and Combigan® (Brimonidine/Timolol) Fixed Combination on Intraocular Pressure and Ocular Blood Flow in Patients With Primary Open Angle Glaucoma or Ocular Hypertension

Conditions
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Retina, Ocular Physiology

Intervention / Treatment
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* Drug: latanoprost 0.005% + timolol 0,5% fixed combination
* Drug: brimonidine 0,2% + timolol 0,5% fixed combination


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Men and women over 18 years Unilateral or bilateral primary open angle glaucoma, ocular hypertension, exfoliation glaucoma, pigmentary glaucoma with IOP between 22 -35mmHg At least 3 reliable visual field testings 4 weeks for ß adrenergic receptor antagonists and prostaglandin analogues, 2 weeks for adrenergic agonists, and 5 days for cholinergic agonists and carbonic anhydrase inhibitors Exclusion Criteria: History of acute angle closure Closed or barely open anterior chamber angle Mean deviation of visual field testing > 10 Intraocular surgery or argon laser trabeculoplasty within the last six months Ocular inflammation or infection within the last three months Contact lenses Patients with bradycardia (heart rate < 50 beats/min) Second and third degree heart block Asthma COPD Congestive heart failure Severe renal impairment (creatinine clearance < 1.8 L/h) History of hypersensitivity to one of the study drugs or drugs with similar chemical structure Topical or systematically/oral therapy with steroids History of non-IOP responder to beta-blockers, alpha-2 adrenergic or prostaglandin analogues Pregnancy

Ages Eligible for Study
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Minimum Age: 18 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Treatment
Allocation: Randomized
Intervention Model: Crossover Assignment
Masking: Quadruple


Arms and Interventions

| Intervention/Treatment |
| --- |
|Drug: latanoprost 0.005% + timolol 0,5% fixed combination|1 drop per day and eye for 6 weeks|
|Drug: brimonidine 0,2% + timolol 0,5% fixed combination|1 drop twice a day per eye for 6 weeks|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Optic disc blood flow measured with laser Doppler flowmeter (rel units) |  | 12 weeks | 
| Intraocular pressure (mmHg) |  | 12 weeks | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Retrobulbar flow velocities as measured with color Doppler imaging (cm/s) |  | 12 weeks | 
| Mean defect of visual field measured with automated perimetry (dB) |  | 12 weeks | 
| Corneal thickness as measured with pachymetry (µm) |  | 1 day | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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xalacom, combigan, ocular blood flow