REDUCTION OF INTRAOCULAR-PRESSURE WITH TREATMENT OF LATANOPROST ONCE-DAILY IN PATIENTS WITH NORMAL-PRESSURE GLAUCOMA

Purpose: Currently available ocular hypotensive agents often fail to l ower intraocular pressure (IOP) in patients with normal-pressure glauc oma (NPG). The authors evaluated the IOP-reducing potential and side e ffects of latanoprost, a newly developed ocular hypotensive agent, in this patient group. Methods: A randomized, double-masked, placebo-cont rolled cross-over study was performed in 30 patients with NPG, 29 of w hom completed the study. During three periods of 3 weeks each, patient s received, in a random order, 50 mu g/ml latanoprost once daily, 15 m u g/ml latanoprost twice daily, and placebo. Per dose, one drop of the study medication was applied topically in both eyes. At the end of ea ch treatment period, diurnal IOP measurements were obtained. General a nd ocular symptoms were recorded, and a detailed ocular examination wa s performed on each visit to monitor side effects. Results: Average IO P reduction after 50 mu g/ml latanoprost once daily, 15 mu g/ml latano prost twice daily, and placebo was 3.6 +/- 1.0 mmHg (21.3%, P < 0.001) , 2.4 +/- 1.5 mmHg (14.2%, P < 0.001), and 0.4 +/- 1.8 mmHg (2.4%, not significant), respectively. The difference between the two latanopros t dose regimens was significant (P = 0.001). Efficacy of latanoprost c orrelated with initial IOP (r(2) = 0.76, P < 0.001). A mild, but stati stically significant, increase in conjunctival hyperemia was observed in both latanoprost treatment groups.Conclusion: Both latanoprost regi mens significantly reduce IOP in patients with NPG, but 50 mu g/ml lat anoprost once daily is more effective in reducing IOP than 15 mu g/ml latanoprost twice daily. Lowering the concentration did not result in an improved side effects profile. Latanoprost is more effective at hig her IOP levels.