Investigation of Refractive Errors in Congenital Nasolacrimal Duct Obstruction.

Objectives: Congenital nasolacrimal duct obstruction (CNLDO) is a condition that can lead to the development of anisometropia and amblyopia. This study aimed to identify refractive errors in children with unilateral and bilateral CNLDO. Methods: A total of 220 eyes from 110 patients with CNLDO were retrospectively analyzed in this study. All patients underwent at least one surgery, and their most recent refractive errors were compared based on the laterality of the disease. The risk factors for amblyopia were established in accordance with the 2013 and 2021 American Association for Pediatric Ophthalmology and Strabismus guidelines. The investigated risk factors included disease laterality, surgical technique, number of surgeries, age at the time of surgery, and manifest strabismus. Results: The nasolacrimal duct obstruction was unilateral in 66.4% (n=73) of the patients. The average ages at the last examination and at the time of surgery were 57.3±37.6 months (range: 12-153 months) and 29.6±22.3 months (range: 12-128 months), respectively. Hypermetropia was the most common refractive error, followed by astigmatism. The anisometropia and amblyopia rates were 11.8% (n=13) and 5.4% (n=6), respectively. No significant refractive difference was observed between the eyes in unilateral and bilateral CNLDO (p>0.05). After regression analyses, manifest strabismus was the only factor associated with amblyogenic risk factors in children with CNLDO (odds ratio = 0.132, 95% confidence interval = 0.529-17.400, p<0.001). Conclusion: As a result, children diagnosed with CNLDO should be treated at as optimal time as possible, and visual maturation should be monitored for the development of high hypermetropia, anisometropia, and amblyopia. These children should receive a complete ophthalmic examination, including cycloplegic refraction, and orthoptic evaluations.