Comparison of the effects of dorzolamide/timolol and latanoprost/timolol fixed combinations upon intraocular pressure and progression of visual field damage in primary open-angle glaucoma

Abstract

Objective:

To report the long-term effect of the dorzolamide/timolol (DTFC) and latanoprost/timolol (LTFC) fixed combinations on intraocular pressure (IOP) and visual field defects over time in naïve primary open-angle glaucoma (POAG) patients.

Study design and methods:

Prospective, 4-year, open-label, interventional study. Setting: high-volume outpatient clinic. Patients: 178 patients were assigned to receive medical treatment with either DTFC or LTFC. Intervention: over 4 years, tri-monthly IOP and yearly visual field assessment (Octopus 101, Program G2). Outcomes: effect of treatment on IOP, visual field indices mean defect (MD), and visual field indices variance loss (VL) over time.

Results:

DTFC and LTFC significantly (p ≤ 0.001) reduced mean IOP over time (from 22.6 ± 3.0 to 13.8 ± 1.9 mmHg and from 22.3 ± 4.0 to 14.7 ± 1.9 mmHg, respectively). In all, 56 patients (70.9%) and 14 (17.9%) showed a significant MD improvement in the DTFC- and LTFC-treated groups, respectively, p = 0.0001. DTFC progressively and significantly decreased mean VL (from 30.21 ± 23.88 to 8.11 ± 8.50 dB). Mean sensitivity slopes during follow-up were 1.14 dB/year and −0.34 dB/year for DTFC and LTFC treatment groups, respectively; p = 0.028.

Conclusion:

Both treatments significantly reduced IOP as compared with baseline. Additionally, treatment with dorzolamide/timolol fixed combination seem to be effective in preventing glaucomatous visual field progression. This study has some limitations that should be noted, among them its open-label design.

Key words::

• Dorzolamide/timolol
• Fixed-combination therapies
• Glaucoma
• Latanoprost/timolol

Transparency

Declaration of funding

The authors received no funding for conducting the study or for the preparation of this article.

Declaration of financial/other relationships

The authors have disclosed that they have no proprietary or financial interest in any material or methods mentioned.

Some peer reviewers receive honoraria from CMRO for their review work. The peer reviewers of this paper have disclosed that they have no relevant financial relationships.

Acknowledgements

The authors have disclosed that they had no outside editorial assistance in preparing this manuscript.