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

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.

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.