Outcome of monocanalicular intubation for complex congenital nasolacrimal duct obstruction: the role of age

Objective: Complex congenital nasolacrimal duct obstruction (CNLDO) is caused by pathologies other than the typical incomplete perforation of the thin membrane in the distal end of the nasolacrimal duct (NLD). Our purpose was to determine the success of silicone tube insertion for such complex CNLDO cases. Methods: Children who met the defined criteria for complex CNLDO and underwent monocanalicular silicone tube insertion between April 2016 and December 2020 were included. The tube was retained for 6-8 weeks and the final outcome was measured 3-4 months after tube removal. If the patients were totally symptom free, the outcome was recorded as complete success. Acceptable outcome was defined as Munk score ≤ 1 (requiring less than twice daily dabbing) and others were classified as failed. Results: Initially, 147 eyes of 132 patients underwent NLD intubation. However, after exclusion of the 11 cases with spontaneous tube extrusion (7.48%), 136 eyes of 121 patients entered the final analysis. The mean age was 23.9 ± 13.0 months (range 8-73 months). The outcome was complete success in 100 eyes (73.5%), acceptable in 16 (11.8%), and failure in 20 eyes (14.7%). The differences in the outcome of the procedure for the eyes based on history of previous probing and age was not statistically significant. Conclusions: NLD intubation with monocanalicular stent is effective in the resolution of complex CNLDO in 85% of cases. This procedure is associated with infrequent complications, like tube loss. The success is not negatively affected by older age and previously failed probing history. Abbreviations: CNLDO = congenital nasolacrimal duct obstruction, NLD = nasolacrimal duct