Second-line therapy with dorzolamide/timolol or latanoprost/timolol fixed combination versus adding dorzolamide/timolol fixed combination to latanoprost monotherapy
- 1Glaucoma Unit, 1st University, Department Ophthalmology, Thessaloniki, Greece
- 2Charleston Research Company, LLC, Charleston, South Carolina, USA
- 3Carolina Eye Institute, University of SC, Columbia, South Carolina, USA
- 4PRN Pharmaceutical Research Network, LLC, Dallas, Texas, USA
- Dr W C Stewart, 5001 LBJ Freeway, Suite 700, Dallas, TX 75244, USA;
- Accepted 13 July 2008
- Published Online First 14 August 2008
Objective: To evaluate open-angle glaucoma patients, who were insufficiently controlled on latanoprost monotherapy, to determine the 24 h intraocular pressure (IOP) efficacy and safety when changing them to dorzolamide/timolol (DTFC) or latanoprost/timolol fixed combination (LTFC) or adding DTFC.
Methods: A prospective, observer-masked, placebo-controlled, crossover, comparison. Consecutive adults with primary open-angle or exfoliative glaucoma who exhibit a mean baseline IOP >21 mm Hg on latanoprost monotherapy were randomised for 3 months to: DTFC, LTFC or DTFC and latanoprost. Patients were then crossed over to the next treatment for periods 2 and 3. At the end of the latanoprost run-in and after each 3-month treatment period, patients underwent 24 h IOP monitoring.
Results: 31 patients completed this study. All three adjunctive therapies significantly reduced the IOP at each time point and for the mean 24 h curve, except at 18:00 and 02:00 with DTFC and 02:00 with LTFC. When the three treatments were compared directly, the DTFC and latanoprost therapy demonstrated lower IOPs versus the other treatment groups, including: the mean 24 h pressure, maximum as well as minimum levels and individual time points following a modified Bonferroni correction (p<0.0032).
Conclusions: This study showed DTFC, LTFC and the addition of DTFC to latanoprost significantly decrease the IOP compared with latanoprost alone, but the latter therapy regime yields the greatest IOP reduction.
Funding: The clinical site was supported in part by an unrestricted grant from Merck. The administrative site, PRN Pharmaceutical Research Network, LLC, received no financial support for this study.
Competing interests: AGP Konstas has received research funding and honoraria from Alcon, Allergan, Merck and Pfizer.
Ethics approval: Ethics approval was provided by the Bioethics Committee of the Medical School, Aristotle University of Thessaloniki.
Patient consent: Obtained.