Prevalence of Amblyogenic Risk Factors in Congenital Nasolacrimal Duct Obstruction in a Developing Country

PURPOSE: Conventionally, congenital nasolacrimal duct obstruction (NLDO) has been treated as an entity with no bearing on development of visual acuity and routine refraction is not done considering the volume of patients in a in a developing Asian country like India. This research was designed to study the prevalence of amblyogenic refractive error in patients with congenital NLDO, as compared to an age-matched control group, in a developing country. METHODS: In this study, 89 patients with congenital NLDO and 78 patients as age matched controls, less than 4 years of age were included at a tertiary care centre in India. All underwent a complete ocular examination and risk factors for amblyogenic refractive error were noted based on the AAPOS guidelines. RESULTS: There was no gender predisposition and no significant difference between the two groups in terms of mode of delivery, orthoptic check-up, keratometry, axial length, fundus or anterior segment examination. Amblyogenic refractive error, as defined by the AAPOS guidelines, was found in 18 (20.5%) patients in the case group compared to 3 (3.8%) in the control group, and this was as follows: astigmatism in 10, anisometropia in 5, hyperopia in 3 subjects, and myopia in 1. These risk factors were not greater in children with unilateral NLDO compared to bilateral NLDO, but both were greater than their control group. There was also no significant difference found between the two groups in terms of distribution of anisometropia. CONCLUSIONS: The prevalence of amblyogenic refractive error in congenital NLDO was significantly higher than in the control group. Hence, a thorough evaluation is warranted in cases of congenital NLDO for early detection amblyogenic refractive error.