Length Indicator of Lacrimal Pathway in Probing with Congenital Nasolacrimal Duct Obstruction

ABSTRACT

PURPOSE: To differentiate complex obstruction from the nasal cavity floor when performing probing in congenital nasolacrimal obstruction. METHODS: Twenty-five eyes of 23 patients with congenital nasolacrimal duct obstruction were treated by probing from January to December 2003. We measured the length between the medial canthus and nasal ala and between the punctum and nasal floor after positioning the probe in the nasal cavity and compared the two lengths. RESULTS: There were 15 males and 10 females. Their mean age was 11.48+/-4.32 months. The mean length between the lower punctum and nasal floor was 3.28+/-0.34 cm, and the mean length between the medial canthus and nasal ala was 2.82+/-0.26 cm. The length between the punctum and nasal floor was longer than that between the medial canthus and nasal ala (p<0.01). There was a positive relationship between two lengths (r=0.805, p<0.01). CONCLUSIONS: Measuring the length between the medial canthus and nasal ala before probing in patients with congenital nasolacrimal obstruction is helpful to distinguish the nasal floor from complex nasolacrimal obstruction when a hard stop is encountered.