Long-term Outcome and Predictors of Silicone Tube Intubation for Patients with Nasolacrimal Duct Obstruction

Purpose: To evaluate the long-term outcome and prognostic factors according to the degree of obstruction after silicone tube intubation in patients with nasolacrimal duct obstruction (NLDO). Methods: From March 2016 to July 2020, the medical records of 145 eyes of 107 patients with NLDO who underwent silicone tube intubation and had been followed for more than 6 months were analyzed retrospectively. The preoperative lacrimal irrigation and degree of obstruction were classified into three groups, and the surgery outcome was also evaluated. Successful surgery was defined as a case in which the epiphora improved, the height of the tear meniscus decreased, and there was no reflux in the postoperative lacrimal irrigation. Risk factors for recurrence were analyzed using a Cox proportional hazards model and Kaplan-Meier survival analysis. Results: Surgery was successful in 99 eyes (68.3%), while recurrence occurred in 46 eyes (31.7%) after silicone tube removal. The average follow-up period was 23.09 months. The recurrence rate was 30.4%, 29.3%, and 50.0% for functional, partial, and total NLDO, respectively, and did not differ significantly (p = 0.300). The risk of recurrence was higher at older age (adjusted hazard ratio [aHR] = 1.079, p < 0.001) and with a history of facial palsy (aHR = 4.031, p = 0.019), and was lower in the functional NLDO group than in the total NLDO group (aHR = 0.368, p = 0.040). In the Kaplan-Meier survival analysis, the total NLDO group differed significantly from the functional NLDO group (log-rank, p = 0.011). Conclusions: Age, a history of facial palsy, and the degree of preoperative obstruction were associated with the prediction of recurrence after silicone tube intubation in patients with NLDO.