Comparison of allergy rates in glaucoma patients receiving brimonidine 0.2% monotherapy versus fixed-combination brimonidine 0.2%–timolol 0.5% therapy

ABSTRACT

Objective: To evaluate the incidence of ocular allergy in glaucoma patients prospectively treated with 0.2% brimonidine–0.5% timolol fixed combination (Combigan) compared with the incidence of ocular allergy in patients treated with 0.2% brimonidine (Alphagan‡) monotherapy.

† Combigan and ‡Alphagan are registered trade names of Allergan Inc, Irvine, CA, USA

Study design and methods: This was a comparative, non-randomized, single-site, interventional study involving patients with primary open-angle glaucoma or exfoliation syndrome who had not previously used brimonidine in any formulation and had no history of ocular allergy. In one study arm, 102 patients were prospectively treated with twice-daily 0.2% brimonidine–0.5% timolol fixed combination. In the other study arm, medical charts at the same center were reviewed to identify a control group of 102 patients who had been treated with twice-daily 0.2% brimonidine monotherapy. Follow-up was at 1, 3, 6, 9, 12, 15, and 18 months of treatment.

Main outcome measure: Ocular allergy defined as the presence of follicles and redness severe enough to warrant discontinuation of the medication.

Results: The incidence of ocular allergy over 18 months of treatment was 8.8% (9/102) in the fixed-combination group compared with 17.6% (18/102) in the brimonidine group ( p = 0.097). Kaplan–Meier survival analysis suggested that ocular allergy may be reduced or delayed in patients treated with the brimonidine–timolol fixed combination ( p = 0.066).

Conclusions: The brimonidine–timolol fixed combination was associated with a 50% lower incidence in ocular allergy compared with 0.2% brimonidine monotherapy. This difference between treatments was not statistically significant ( p = 0.097) but is likely to be clinically important. Additional studies are needed to evaluate the incidence of ocular allergy associated with brimonidine–timolol fixed combination treatment.

Key Words::

• Brimonidine
• Fixed combination
• Glaucoma
• Ocular allergy
• Timolol

Acknowledgments

Declaration of interest: This study was conducted independently by the authors with no financial support from any company. Kate Ivins, PhD, provided freelance statistical analysis and medical writing assistance and Pacific Communications, Costa Mesa, CA, USA provided editorial assistance. Manuscript preparation support was provided by Allergan, Inc. The authors declare no financial interest in the study drugs or in the manufacturer of the study drugs, Allergan, Inc.

Notes

* Preliminary results of this study were presented at the American Glaucoma Society Annual Meeting, March 2–5, 2006, Charleston, SC, USA

† Combigan and ‡Alphagan are registered trade names of Allergan Inc, Irvine, CA, USA