During the glaucomatous disease process, subpopulations of cells may be dead, damaged or healthy. Visual function changes could be observed due to a recovering of the suffering ganglion cells after the intraocular pressure reduction. This study aims at evaluating the correlation between intraocular pressure reduction and visual function changes in glaucoma patients after using antiglaucoma medications.

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.

Inclusion Criteria:

• Primary open angle glaucoma
• Intraocular pressure greater than 21 mmHg

Exclusion Criteria:

• Best corrected visual acuity (BCVA) worse than 20/80
• Significant media opacity
• History of steroid use