Effect of dorzolamide/timolol combination on the visual field in glaucoma

Abstract

PurposeTo evaluate the effect of treatment for 3 years with a dorzolamide/timolol (1%/0.5%) fixed combination (DTFC) on visual field progression in patients with open-angle glaucoma.ParticipantsA total of 14 consecutive patients were enrolled who had been previously treated with monotherapy or any combination of a beta blocker, carbonic anhydrase inhibitor, and/or prostaglandin analog for primary open-angle glaucoma (POAG; n=4) or normal-tension glaucoma (NTG; n=10).MethodsPatients were switched to DTFC from their prior glaucoma therapy. The IOP was measured at intervals of 4–6 weeks, and the visual fields were examined at least twice a year for 3 years. The annual change of mean deviation (MD slope) was used to quantify visual field loss.ResultsThe mean MD value was −5.9±5.0 dB at baseline; it was −5.6±4.8 dB at 12 months, −5.9±5.0 dB at 24 months, and −5.6±5.1 dB at 36 months after switching. The mean MD slope was −0.2±0.8 dB/year before switching and 0.3±1.3 dB/year from baseline to 1 year, −0.3±1.1 dB/year from 1–2 years, and 0.3±0.9 dB/year from 2–3 years after switching. The mean MD slope from baseline to 36 months was correlated with the IOP reduction rate at 36 months after switching. Visual field progression was associated with the IOP reduction rate at 12 months after switching.ConclusionSwitching to DTFC from prior glaucoma therapy improved the MD slope for at least 3 years. Reduction of the IOP after switching to DTFC was effective for delaying visual field progression. Although our study was not nonrandomized and was small in scale, the findings suggest that DTFC might have a beneficial effect on the visual fields in patients with open-angle glaucoma.

Roles of CYP2C19 Gene Polymorphisms in Susceptibility to POAG and Individual Differences in Drug Treatment Response

“…A study conducted by Frezzotti Paolo observed that, despite the IOP-lowering effect, 2 formulations of timolol caused varying degrees of adverse events [ 21 ]. Therefore, combination therapy for glaucoma aims to achieve minimum medication, reduced IOP-lowering doses, and improved convenience and compliance for patients, leading to excellent drug effects [ 22 , 23 ]. Owing to the drug metabolic enzymes, treatment of POAG using timolol is improved; however, patients carrying different CYP2C19 phenotypes may differ in drug response [ 24 ].…”

Primary Open-Angle Glaucoma Progression in Glaucoma Patients with Unchanged Topical Treatment over 3 Years – Retrospective Observational Cohort Analysis

“…In the context of present results, of particular interest are observations regarding dorzolamide. Takeda et al have shown that switching to a timolol/dorzolamide fixed combination from prior glaucoma therapy improved the MD slope for at least 3 years [13]. In a 4-year open-label interventional study, Pajic et al demonstrated superior preservation of VF in the timolol/dorzolamide treated-group of glaucoma patients compared to timolol/latanoprost-treated group (in contrast to our analysis, where only PA was used); interestingly, in this study, structural damage measurements (with Heidelberg Retina Tomograph) revealed no differences in progression between the groups [9].…”