Nasolacrimal sounding

The nasolacrimal duct transports tears from the lacrimal sac to the nasal cavity, tears normally drain through small openings located in the corners of the upper and lower eyelids called tear points; the tear obstruction can be in one or both eyes, and when this occurs, the eyes fill with tears.
Tear duct catheterization is a procedure that is performed on an outpatient basis and can be performed under general anesthesia or under sedation, a probe is inserted into the tear of the eye towards the point of obstruction of the nasolacrimal duct to open it and allow the correct drainage of the tears.