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

Official Title: “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”

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.

Intervention(s) in this Clinical Trial

• 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

Primary Measures

• Optic disc blood flow measured with laser Doppler flowmeter (rel units)
  • Time Frame: 12 weeks
    Safety Issue?: No
• Intraocular pressure (mmHg)
  • Time Frame: 12 weeks
    Safety Issue?: No

Secondary Measures

• Retrobulbar flow velocities as measured with color Doppler imaging (cm/s)
  • Time Frame: 12 weeks
    Safety Issue?: No
• Mean defect of visual field measured with automated perimetry (dB)
  • Time Frame: 12 weeks
    Safety Issue?: No
• Corneal thickness as measured with pachymetry (µm)
  • Time Frame: 1 day
    Safety Issue?: No

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

Gender Eligibility for this Clinical Trial: Both

Minimum Age for this Clinical Trial: 18 Years

Maximum Age for this Clinical Trial: N/A

Are Healthy Volunteers Accepted for this Clinical Trial?: No

Lead Investigator: Medical University of Vienna Other

Overall Clinical Trial Officials and Contacts

Michael Wolzt, MD Principal Investigator Department of Clinical Pharmacology, Medical University of Vienna  

Overall Contact: Gerhard Garhöfer, MD 43-14-0400-2981 gerhard.garhoefer@meduniwien.ac.at

Information obtained from ClinicalTrials.gov on February 12, 2012

Link to the current ClinicalTrials.gov record. http://clinicaltrials.gov/show/NCT00706927

Study ID Number: OPHT-241005

ClinicalTrials.gov Identifier: NCT00706927

Health Authority: Austria: Agency for Health and Food Safety