Effect of over-the-counter brimonidine tartrate 0.025% ophthalmic solution on pupil size in healthy adults

Purpose To evaluate the effect of brimonidine tartrate 0.025% ophthalmic solution on pupil size under scotopic conditions in healthy adults Methods Pupil size was measured in 56 eyes of 28 volunteer participants using a pupillometer under scotopic conditions. Age, gender, and iris color were recorded. Subjects using any ophthalmic medications other than artificial tears were excluded. The pupil size was subsequently measured again under scotopic conditions 60 min after instillation of brimonidine tartrate 0.025% ophthalmic solution. Results Statistically significant miosis was seen after instillation of brimonidine tartrate 0.025% (p = 0.04). Average pupil size prior to brimonidine 0.025% instillation was 7.28 ± 1.05 mm, and average pupil size after instillation of brimonidine 0.025% was 6.36 ± 1.68 mm, a reduction of − 23.7% in pupil area. Subjects with light irides demonstrated a greater miotic effect than subjects with dark irides (1.55 mm vs. 0.67 mm, p