Amblyopia risk factors in infants with congenital nasolacrimal duct obstruction

Purpose: This study aims to report the prevalence of amblyopia risk factors in patients with congenital nasolacrimal duct obstructions. Methods: We recruited patients who were treated for congenital nasolacrimal duct obstruction from April 2007 to December 2011 at Korea University Ansan Hospital. We evaluated visual acuity and refraction, performed strabismus test and slit-lamp examination, and assessed marginal reflex distance 1 (MRD1) to rule out amblyopia risk factors. Results: We examined 26 children among 115 patients. Ten patients underwent probing procedure and 16 underwent Monoka stent intubation. Nine (35%) patients showed amblyopia risk factors, which occurred in the same eye as the congenital nasolacrimal duct obstruction in 8 (89%) patients. Seven out of 9 patients had refractive error alone, and 2 patients had both refractive error and strabismus. One (11%) had anisometropia, 2 (22%) had hyperopia, and 8 (89%) had astigmatism. Conclusion: Children with congenital nasolacrimal duct obstruction had a higher prevalence of amblyopia risk factors than children in the general population. Children with congenital nasolacrimal duct obstruction require special attention and treatments for refractive error. We recommend early treatment, such as probing or intubation, for congenital nasolacrimal duct obstruction.