The study includes two sequential groups: Group 1 subjects are fitted with PPDS (O‑PPDS [130 µg olopatadine] or placebo-PPDS) in the lower puncta of each eye, and Group 2 subjects are fitted with PPDS ...

Under normal conditions, tears in the eyes are drained into the lacrimal sac through small openings called the upper and lower puncta located at the inner corner of the eye (called medial canthus).

Under normal conditions, tears in the eyes are drained into the lacrimal sac through small openings called the upper and lower puncta located at the inner corner of the eye (called medial canthus).