To evaluate the clinical result of silicone tube intubation through Hasner's valve according to nasolacrimal duct resistance under intranasal endoscopic guidance in partial acquired nasolacrimal duct obstruction patients.

The present study enrolled a total of 50 eyes from 31 patients diagnosed with partial acquired nasolacrimal duct obstruction in the Department of Ophthalmology, Chonbuk National University Hospital from 2012 January to 2012 December. Silicone tube intubation was done through the Hasner's valve and confirmed by intranasal endoscopy and the nasolacrimal duct resistance was measured. Success was defined as the disappearance of epiphora, and failure was defined as the maintenance of epiphora after silicone tube intubation.

There were 8 male patients and 23 female patients, ages between 32 to 80 and the average age was 61.4 years old. 3 eyes of 3 patients (6%) had no resistance, 26 eyes of 17 patients (52%) had mild resistance, 17 eyes of 15 patients (34%) had moderate resistance and 4 eyes of 3 patients (8%) had severe resistance. The success was 44 eyes (88%) and the failure was 6 eyes (12%). In the no resistance and mild resistance groups the success rates were both 100%, while an 82% of success rate in the moderate resistance group and 25% success rate in the severe resistance group were observed. The success rates showed clear distinction between severe, moderate and mild resistance patients.

Ensuring the passage of a silicone tube through Hasner's valve increases the success rate in the functional aspect; however, the resistance of the nasolacrimal duct can highly influence the success rate. Therefore, if a patient has severe nasolacrimal duct resistance, dacryocystorhinostomy should be considered earlier.