BACKGROUND The purpose of this study was to characterize current patterns of treatment of glaucoma and ocular hypertension and to examine the effect of those patterns on intraocular pressure (IOP) control and persistence on therapy. METHODS A retrospective chart review was conducted at 3 ophthalmology practices in Alberta. Data were collected for patients who had begun therapy for newly diagnosed primary open-angle glaucoma or ocular hypertension between May 1, 1998, and Sept. 30, 1999 (phase 1), and for patients who had begun second-line therapy after initial therapy with a beta-blocker had failed (phase 2). Data were collected for a minimum of 24 months for phase 1 and a minimum of 18 months for phase 2. RESULTS We included 115 patient charts in phase 1 and 93 in phase 2. In each phase, the patients for whom latanoprost had been prescribed in unfixed combination with a beta-blocker had the greatest mean percentage reduction in IOP at month 24, and the patients for whom latanoprost had been prescribed alone or in combination with a beta-blocker were more likely to still be on initial therapy at month 24; the difference in persistence on therapy was statistically significant only in phase 1 (p = 0.001). The mean number of switches in therapy was smaller in phase 1 than in phase 2 in all therapy groups. CONCLUSIONS Compared with other first- and second-line forms of therapy, treatment with latanoprost, alone or in combination with a beta-blocker, was associated with greater reductions in IOP, better therapeutic persistence, fewer therapy switches and fewer ophthalmologist visits over a 2-year period.