Br J Ophthalmol 92:1498-1502 doi:10.1136/bjo.2008.145219
  • Original Article
    • Clinical science

Second-line therapy with dorzolamide/timolol or latanoprost/timolol fixed combination versus adding dorzolamide/timolol fixed combination to latanoprost monotherapy

  1. A G P Konstas1,
  2. D Mikropoulos1,
  3. A T Dimopoulos1,
  4. G Moumtzis1,
  5. L A Nelson2,
  6. W C Stewart3,4
  1. 1
    Glaucoma Unit, 1st University, Department Ophthalmology, Thessaloniki, Greece
  2. 2
    Charleston Research Company, LLC, Charleston, South Carolina, USA
  3. 3
    Carolina Eye Institute, University of SC, Columbia, South Carolina, USA
  4. 4
    PRN Pharmaceutical Research Network, LLC, Dallas, Texas, USA
  1. Dr W C Stewart, 5001 LBJ Freeway, Suite 700, Dallas, TX 75244, USA; info{at}
  • 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.