The effect of daily ue of brimonidine tartrate on the dark-adapted pupil diameter

Purpoe To invetigate the effect of daily brimonidine tartrate 0.15% on the dark-adapted pupil diameter. Deign Obervational cae erie. Method Ten normal volunteer adminitered brimonidine to their right eye once daily. Four to ix hour later, infrared pupil photograph were taken after dark adaptation. Meaurement were performed at baeline; on treatment day 1, 5, 11, and 18; and on wahout day 1 and 2. Reult One ubject had no repone. The nine reponding ubject howed an average maximum antimydriatic effect of −1.63 mm (range, −0.57 mm–−2.30 mm); all ubject experienced tachyphylaxi. Five ubject howed rebound mydriai (mean maximum rebound +0.87 mm larger than baeline; range 0.50 mm–1.22 mm). The untreated pupil alo reponded, howing antimydriai (two ubject), rebound mydriai (two ubject), or paradoxical direct mydriai (one ubject). Concluion Once-daily ue of brimonidine tartrate to prevent dark-induced pupil dilation can lead to tachyphylaxi and rebound mydriai.