Congenital Nasolacrimal Duct Obstruction and Refractive Amblyopia Risk Factors: Effect of Age at the Time of Probing

OBJECTIVES: To determine whether treatment time of congenital nasolacrimal duct obstruction (CNLDO) has any effect on refractive amblyopia risk factors (ARFs). METHODS: This is a cross-sectional study and it was conducted in the Pediatric Ophthalmology Department at Kayseri City Training and Research Hospital. The ages of 174 patients who underwent probing were obtained from electronic medical charts and used to divide the patients into two groups: an early-probing group (<24 months old) and a late-probing group (≥24 months old). After inclusion criteria were applied, a pediatric ophthalmologist examined 189 eyes of the 174 patients. The groups were evaluated and compared for cycloplegic refractive errors. RESULTS: The median age of patients who underwent probing was 30 months (ranging from 11–44 months). A total of 40 of 189 eyes (21.2%) examined had refractive ARFs, which were significantly more prevalent in the late-probing group (p=0.044). The ARFs associated with astigmatism were greater in the late- versus the early-probing group (p=0.037), whereas no other refractive ARFs or anisometropia differed between the groups (p=0.887 for myopia, p=0.364 for hyperopia, and p=0.672 for anisometropia). Astigmatic ARFs were significantly higher in the late-treatment group. CONCLUSION: Astigmatic ARFs were significantly higher in the late-treatment group. Therefore, ophthalmologists should regularly monitor the refractive status of children with CNLDO, especially those treated after 24 months old.