Brimonidine related acute follicular conjunctivitis: Onset time and clinical presentations, a long-term follow-up

To evaluate the duration of topical brimonidine therapy before the onset of brimonidine-related allergic conjunctivitis and the clinical characteristics associated with the development of brimonidine allergy.We retrospectively enrolled patients who presented brimonidine allergy from December 1, 2008 to November 30, 2020. The duration of brimonidine treatment, concomitant medications, benzalkonium chloride (BAK) exposure, change in IOP, and season of onset were evaluated.292 patients were included, among which 147 were female and 145 were male. The mean age was 58.3 ± 13.6 years old. The mean (median) duration of brimonidine therapy was 266.6 (196) days, with a peak at 60-120 days. The duration was similar whether the patients received brimonidine monotreatment or in combination with other glaucoma drugs, with or without BAK. The IOP increased by 5.6% after brimonidine allergy (P