Continuous Intraocular Pressure (IOP) Measurement and Ability to Detect Treatment Effect

* Participants are washed ot from all glaucoma medication for 6 weeks * one eye per participant is investigated (study eye) * 24-h intraocular pressure (IOP) curve is obtained with Goldmann tonometry and Sensimed contact lens sensor tonometry twice, in 14 days * for Sensimed contact lens curves median values (in arbitrary units), for Goldmann applanation tonometry, mean and SD values are used to characterize the curves, for comparisions % changes are used for the corresponding time periods * treatment (travoprost 0.005% 1/day) is given to all eyes for 3 months 24-h Goldmann and Sensimed IOP curves are repeated * IOP curves are determined in arbitrary units and mmHg, respectively, and compared for reproducibility (untreated phase) and relative (%)change (untreated curve vs. under treatment curve) with both methods, respectively