Ocular Physiology, Retina
Conditions
Keywords
xalacom, combigan, ocular blood flow
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 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.
Interventions
DRUGlatanoprost 0.005% + timolol 0,5% fixed combination
1 drop per day and eye for 6 weeks
DRUGbrimonidine 0,2% + timolol 0,5% fixed combination
1 drop twice a day per eye for 6 weeks
Sponsors
Medical University of Vienna
Study design
Allocation
RANDOMIZED
Intervention model
CROSSOVER
Primary purpose
TREATMENT
Masking
QUADRUPLE (Subject, Caregiver, Investigator, Outcomes Assessor)
Eligibility
Sex/Gender
ALL
Age
18 Years to No maximum
Healthy volunteers
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
Design outcomes
Primary
| Measure | Time frame |
|---|---|
| Optic disc blood flow measured with laser Doppler flowmeter (rel units) | 12 weeks |
| Intraocular pressure (mmHg) | 12 weeks |
Secondary
| Measure | 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 |
Countries
Austria
Outcome results
None listed