Endoscopic-assisted probing for congenital nasolacrimal duct obstruction

Purpose To determine the success rate of initial probing in children with congenital nasolacrimal duct obstruction (CNLDO) at different ages using nasal endoscopy, and to identify the anatomical sites of blockage within the drainage system. Methods A total of 87 eyes from 67 consecutive children with CNLDO underwent endoscopic nasolacrimal duct (NLD) probing under general anaesthetic. Patients who had had previous probings were excluded from the study. Diagnosis was based on history of epiphora since birth or shortly after, and fluorescein dye disappearance test (FDDT). Cure was judged as complete or near-complete remission of symptoms and signs and a normal FDDT. Results The age range was 12-91 months (mean 32.3 months). The success rates of probing were: 100% (58/58) for atresia and stenosis at the lower NLD, 100% (13/13) for punctal stenosis, 55.6% (5/9) for functional epiphora, and 0% (0/7) for canalicular and upper NLD obstruction. Age was not found to significantly affect the outcome of probing, whereas site did. Obstruction at canalicular or upper NLD level became more common with increasing age. Conclusion Probing of the nasolacrimal system using the endoscopic approach allows direct visualisation of the distal nasolacrimal duct, which facilitates diagnosis of the anomaly at this site. More complex proximal anomalies became increasingly prevalent in older children, which accounted for the poorer results with increasing age. Site of obstruction has a greater bearing on outcome than patient age.