Differential Regurgitation from the Puncta on Compressing Lacrimal Sacs.

Regurgitation on pressure over the lacrimal sac (ROPLAS) is a common clinical sign that is elicited in nasolacrimal duct obstructions. It is more evident in the presence of lacrimal sac dilatation or non encysted mucoceles. Gabriele Falloppio is credited with the first scientific documentation of a regurgitation on pressure over the lacrimal sac in the 16th century. Regurgitation of the lacrimal sac contents was believed, in the 18th century (Stahl, Platner, and Schobinger), to show differential patterns of exit from the upper or the lower punctum. To the best of our knowledge, no subsequent work focused on verifying this observation. The present case series aims to precisely observe and validate this finding with slow motion, high definition, slit lamp videography to better understand the pathophysiology.