Table 1.

Preoperative diagnosis of the obstruction site by the irrigation test.

Flushing through the inferior canaliculus	Refux	Nasolacrimal duct
Positive to the oropharynx	No	Normal
Positive to the oropharynx	Through the superior canaliculus	Partial obstruction of the nasolacrimal duct
Negative to the oropharynx	Superior canaliculus with secretion	Complete distal obstruction of the nasolacrimal duct
Negative to the oropharynx	Superior canaliculus without secretion	Obstruction of the common canaliculus
Negative to the oropharynx	Through the inferior canaliculus	Obstruction of the inferior canaliculus