Primary open angle glaucoma patients without use of antiglaucoma medications will be enrolled in this study. After inclusion, the patients will randomly receive one of three antiglaucoma medications (timolol maleate 0,5%, brimonidine tartrate 0,2% or travoprost 0,004%) in one randomly selected eye.
The patients will be evaluated with Goldmann applanation tonometry, visual acuity test, contrast sensitivity test, visual quality perception test (visual analogue scale) and standard automated perimetry before and after 4 weeks of glaucoma treatment onset.