Bimatoprost versus timolol and dorzolamide

Abstract

A recent article by Drs Coleman et al1Coleman A.L. Lerner F. Bernstein P. Whitcup S.M. A 3-month randomized controlled trial of bimatoprost (LUMIGAN) versus combined timolol and dorzolamide (Cosopt) in patients with glaucoma or ocular hypertension.Ophthalmology. 2003; 110: 2362-2368Abstract Full Text Full Text PDF PubMed Scopus (48) Google Scholar concluded that bimatoprost lowered intraocular pressure (IOP) more consistently than did combined timolol and dorzolamide in individuals with glaucoma or ocular hypertension uncontrolled on a topical β-blocker alone. However, a concern voiced by the authors (in the article) warrants some caution regarding this conclusion. The stated concern about study design was that the selected patients had not been adequately controlled on timolol maleate monotherapy before randomization, and some may have been poor responders or nonresponders to timolol maleate. From the data presented, it is not possible to determine how much this may have influenced the study's conclusion. Establishing a priori that a meaningful decrease in IOP with timolol alone should be seen in the patients would have avoided the possibility of enrolling timolol nonresponders. Further, the range of IOP response at the various time points throughout the study is not specified. Without these key provisos, the authors' stated conclusion cannot be fully supported. Other investigators2Honrubia F.M. Larsson L.I. Spiegel D. A comparison of the effects on intraocular pressure of latanoprost 0.005% and the fixed combination of dorzolamide 2% and timolol 0.5% in patients with open-angle glaucoma.Acta Ophthalmol Scand. 2002; 80: 635-641Crossref PubMed Scopus (31) Google Scholar, 3Garcia Sanchez J. Spanish Latanoprost Study GroupEfficacy and side effects of latanoprost monotherapy compared to adding dorzolamide to timolol in patients with glaucoma and ocular hypertension—a three-month randomized study.Eur J Ophthalmol. 2000; 10: 198-204PubMed Google Scholar, 4Emmerich K.H. Comparison of latanoprost monotherapy to dorzolamide combined with timolol in patients with glaucoma and ocular hypertension A 3-month randomized study.Graefes Arch Clin Exp Ophthalmol. 2000; 238: 19-23Crossref PubMed Scopus (46) Google Scholar, 5Bron A.M. Emmerich K.H. Latanoprost versus combined timolol and dorzolamide.Surv Ophthalmol. 2002; 47: S148-54Abstract Full Text Full Text PDF PubMed Scopus (17) Google Scholar mentioned in this article have used a similar study design. This alone is not a sufficient rationale to support the current study's design, nor does it justify the comparison of results for these various studies. Rather, it speaks to the necessity to design and enroll clinical trials in a fashion that allows more definite conclusions to be drawn. A 3-month randomized controlled trial of bimatoprost (LUMIGAN) versus combined timolol and dorzolamide (Cosopt) in patients with glaucoma or ocular hypertensionOphthalmologyVol. 110Issue 12PreviewTo compare the efficacy and safety of topical bimatoprost (LUMIGAN; Allergan, Inc., Irvine, CA) once daily with that of topical combined timolol and dorzolamide (Cosopt; Merck & Co, Inc., Whitehouse Station, NJ) twice daily. Full-Text PDF Bimatoprost versus timolol and dorzolamide: Author replyOphthalmologyVol. 112Issue 2PreviewWe are pleased that the article describing our comparison of bimatoprost with combined timolol and dorzolamide has generated interest. Because our conclusion that bimatoprost is more effective than the combination is supported by the data from our study, we appreciate the opportunity to respond to Dr Tressler's comments, which bring up some issues that need to be clarified. Full-Text PDF