An Evaluation of the Rate of Nonresponders to Latanoprost Therapy.
Rossetti, Luca MD *; Gandolfi, Stefano MD +; Traverso, Carlo MD ++; Montanari, Paolo MD [//]; Uva, Maurizio MD [S]; Manni, Gianluca MD [P]; Carassa, Roberto MD [up tack]; Mastropasqua, Leonardo MD **; Quaranta, Luciano MD ++; Marchini, Giorgio MD ++++; Ratiglia, Roberto MD *; Orzalesi, Nicola MD *
Journal of Glaucoma.
15(3):238-243, June 2006.
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Purpose: To determine the proportion of patients with primary open-angle glaucoma (POAG) or ocular hypertension (OH) who do not respond to latanoprost therapy.
Methods: Three hundred forty consecutive patients with a new diagnosis of POAG or OH, or previously treated only with a beta-blocker and after an appropriate washout period, were treated with latanoprost for 1 month and then divided into three groups on the basis of the reduction in intraocular pressure (IOP): nonresponders (<15%), responders (>=15% but <30%), and high-responders (>=30%). To give a wide picture of the drug effect, eight different cut-off points were used to present data on distribution of mean IOP reductions. Only the nonresponders entered a randomized cross-over study investigating the efficacy of timolol, brimonidine, and pilocarpine.
Results: IOP at baseline and after 1 month's latanoprost therapy was respectively 24.1 /-1.4 and 16.9 /-2.4 mm Hg, with a mean reduction in IOP of 29.9 /-4.2%. Nonresponders accounted for 4.1% of the patients and high-responders for 41.2%. The nonresponders showed a statistically significant reduction in IOP after brimonidine treatment (P=0.05), whereas the reduction after timolol and pilocarpine treatment was clinically relevant but not statistically significant.
Conclusions: This multicenter prospective study found only 14 of 340 nonresponders to latanoprost. In the cross-over trial on nonresponders, IOP reduction reached statistical significance only after brimonidine, but their small number reduced its statistical power.
(C) 2006 Lippincott Williams & Wilkins, Inc.