Amblyopia risk factors in congenital nasolacrimal duct obstruction: A longitudinal case-control study

Abstract

Purpose To investigate longitudinal changes in risk factors for amblyopia in children treated with congenital nasolacrimal duct obstruction (CNLDO). Methods Retrospective observational case control study. A total of 446 children under 4 years of age who underwent probing and/or intubation for CNLDO between January 2004 and January 2018, and 446 age-matched controls were included. Cycloplegic refraction and ocular alignment were investigated at the time of treatment and after at least one year of symptom improvement. Children were classified as having amblyopia risk factors on the basis of the American Association for Pediatric Ophthalmology and Strabismus guideline in 2013. Main outcome measures The prevalence of amblyogenic refractive errors, and determinants associated with the presence of amblyogenic refractive errors in CNLDO patients. Results The prevalence of amblyogenic refractive errors in CNLDO patients (5.4%) was similar to that of the control group (6.5%) (P = 0.571). After one year of symptom improvement in CNLDO patients, the prevalence of amblyogenic refractive errors was 4.7%. There was no difference in the prevalence of amblyogenic refractive errors between unilateral and bilateral CNLDO patients. Multivariate analysis revealed that manifest strabismus was the only risk factor related with the presence of amblyogenic refractive errors (odds ratio = 6.383, confidence interval = 1.205–33.826, P = 0.029). Conclusions This study found no evidence to suggest that the prevalence of amblyopia risk factors is higher in CNLDO patients compared with normal controls. Manifest strabismus was the only determinant associated with the presence of amblyogenic refractive errors.

Success rates of probing for congenital nasolacrimal duct obstruction at various ages

“…Bilateral obstruction, occurring in 9–47.5% [ 3 , 4 , 9 , 11 , 18 – 20 , 23 , 26 – 29 , 31 , 33 , 34 , 36 , 38 – 40 ] may indicate a more complicated cause of the condition, create greater technical difficulties during procedures performed under local anesthesia, and thus affect the obtainment of less-satisfactory results, which is also confirmed by our study and reports by other researchers [ 20 , 36 ]. Dietze et al [ 43 ] suggest that patients with trisomy 21, allergic rhinitis/seasonal allergies, history of an upper respiratory tract infection within 1 month and obstructive sleep apnea may be correlated with a higher risk of failure with a probing.…”

“…Several authors have confirmed an increased risk for anisometropia and amblyopia in patients with CNLDO (especially long-term untreated obstructions) [22][23][24][25]. However, the effect of long-term epiphora on visual development in children is debatable and some studies reported no significant differences between children with CNLDO and general population [17,26,27].…”