Intraocular Pressure Lowering Effect of Latanoprost as First-line Treatment for Glaucoma

Purpose:To assess the intraocular pressure (IOP)-reducing effect of latanoprost in treatment-naïve patients with newly detected open-angle glaucoma with no restriction of the level of untreated IOP.Methods:Eighty-six patients (105 eyes) with a diagnosis of open-angle glaucoma received IOP-lowering therapy with latanoprost. The IOP reduction 1 and 3 months after initiation of treatment was recorded.Results:Mean untreated IOP for all eyes was 26.2mm Hg (ranging from 10 to 51mm Hg). The mean pressure reduction was 7.9mm Hg (28%), with equivalent average levels at 1 and 3 months. The reduction in IOP ranged from −2.3 to 25.3mm Hg after 1 month, and from −1.3 to 33.3mm Hg after 3 months. The pressure-lowering effect was considerably more pronounced in eyes with higher untreated IOP; the reduction increased by 0.55mm Hg per mm Hg higher untreated IOP. Four eyes, with untreated IOP within statistically normal limits, had no or negative IOP-reduction. A regression model predicted that IOP reduction ended at untreated IOP ≤16mm Hg. Multiple regression analysis showed that an additional IOP-lowering effect of 1.28mm Hg was achieved in eyes with pseudoexfoliation glaucoma.Conclusions:To the best of our knowledge, this paper is the first to report the IOP-reducing effect of latanoprost treatment at all untreated IOP levels in newly detected glaucoma patients. The effect was proportional to the untreated IOP at all levels above 16mm Hg and better at higher untreated IOP levels, also in relative terms. Our results further confirm the indication of latanoprost as a first-line therapy for glaucoma