First-line latanoprost therapy in ocular hypertension or open-angle glaucoma patients: a 3-month efficacy analysis stratified by initial intraocular pressure

Background: Prospective, multicenter, randomized, double-masked trials have shown latanoprost instilled once daily to be at least as effective as and generally superior to timolol administered twice daily and to be as effective as other frequently prescribed prostaglandin analogues. This study prospectively assessed the efficacy of latanoprost monotherapy in a large cohort of treatment-naive patients with a broad range of baseline intraocular pressure (IOP) levels treated in actual clinical practice settings. Methods: This prospective, open-label, multicenter, uncontrolled, phase IV study included treatment-naive ocular hypertension or open-angle glaucoma subjects initiating latanoprost once daily (evening). IOP levels were measured at baseline and after 1 and 3 months. The primary efficacy outcome was mean change in IOP from baseline to month 3. Analyses were stratified by baseline IOP: >= 20 and <24 mmHg vs >= 24 mmHg. Results: Efficacy analyses (intent to treat) included 572 subjects: 20 to <24 mmHg group, N = 252; >= 24 mmHg group, N = 320. Mean baseline IOP levels were 22.2 +/- 0.9 mmHg and 26.7 +/- 2.8 mmHg, respectively. At month 3, significant IOP reductions were seen in both groups (p < 0.0001, within-group differences); reductions were smaller in the 20 to <24 mmHg group (-6.3 +/- 2.4 vs -9.2 +/- 3.7 mmHg, respectively; -28.0 +/- 10.6% vs -34.1 +/- 11.9%, respectively). An IOP reduction of >= 30% from baseline to month 3 was noted in 48.4% and 65.6% of subjects, respectively (p < 0.0001). At month 3, targets IOPs of <= 18 mmHg were achieved by >= 70% of subjects in both groups. Latanoprost was well tolerated with an adverse event profile similar to that reported in the literature. Conclusions: This "real world" study found once-daily latanoprost to be effective and safe in treatment-naive ocular hypertension or open-angle glaucoma patients. Patients with baseline IOP levels of 20 to <24 mmHg as well as >= 24 mmHg benefitted from initial latanoprost therapy.