Optimal timing of lacrimal duct probing for congenital nasolacrimal duct obstruction in infants: A retrospective cohort study.

The optimal timing of lacrimal duct probing for congenital nasolacrimal duct obstruction (CNLDO) remains debated. This study aimed to evaluate the association between age at probing and short term treatment outcomes in infants with CNLDO. This retrospective cohort study analyzed 394 affected eyes from 304 infants aged 3 to 24 months who were diagnosed with CNLDO and underwent lacrimal duct probing at the Ophthalmology Clinic of Tongzhou Maternal and Child Health Hospital of Beijing between August 2019 and July 2024. Patients were categorized into 3 groups according to age at probing: Group A, 3 to 6 months; Group B, 7 to 12 months; and Group C, 13 to 24 months. Short term clinical resolution rates were compared among the groups. Overall, 386 of 394 eyes achieved clinical resolution, corresponding to an overall success rate of 98.0% (95% confidence interval [CI]: 96.0-99.1%). The success rate after the first probing was 87.3% (95% CI: 83.6-90.4%), and the success rate after the second probing was 84.0% (95% CI: 70.9-92.8%). The total success rates were 99.6% in Group A, 97.8% in Group B, and 86.7% in Group C. A significant difference was observed among the 3 groups (P < .001). The success rates in Groups A and B were significantly higher than that in Group C, whereas no significant difference was observed between Groups A and B. Lacrimal duct probing was associated with a high short term success rate in infants with CNLDO, particularly when performed within the first 12 months of life. Because of the retrospective design, limited follow up duration, and small number of patients older than 12 months, these findings should be interpreted as supportive evidence for timely probing rather than definitive proof of an optimal surgical age.