Purpose To compare the success rates of probing versus bicanalicular silastic intubation as the primary treatment for congenital nasolacrimal duct obstruction (CNLDO) in children ≥1 year old.

Study design Prospective, randomised, comparison.

Methods Participants were randomised to undergo probing or bicanalicular silastic intubation. In bilateral cases, the right eye was used for analysis. The procedure was considered successful when all preoperative manifestations disappeared with normal dye disappearance test and a positive Jones primary dye test at least 6 months postoperatively. Secondary outcomes were risk factors for failure. Outcomes were compared between treatments with p<0.05 indicating statistical significance.

Results 207 eyes of 181 children between 1 and 8 years old with CNLDO who had not undergone previous surgical treatment were included in the study. 88 eyes underwent probing with a 84.1% success rate and 93 eyes that underwent bicanalicular silastic intubation had a 89.2% success rate (p=0.429). For simple CNLDO, there was a 94.2% (65/69) success rate with probing and a 90.9% (60/66) success rate with bicanalicular silastic intubation (p=0.687). In complex CNLDO, there was a 47.4% (9/19; p=<0.001) success rate with probing and an 85.2% (23/27; p=0.419) success rate with silastic intubation (p=0.016). Age was not a risk factor for failure in either procedure.

Conclusions Probing for simple CNLDO in young children is adequate. Bicanalicular silastic intubation seems to have a role in achieving successful outcomes in complex CNLDO.