Congenital nasolacrimal duct obstruction update study (CUP study): Paper II - Profile and outcomes of complex CNLDO and masquerades

To assess the profiles and outcomes of complex congenital nasolacrimal duct obstruction (C-CNLDO).

Retrospective interventional case-series was performed on patients diagnosed with C-CNLDO and managed at a tertiary care Dacryology Institute from Jan 2016 to June 2019. Complex CNLDO was diagnosed based on intraoperative findings during probing and are defined as entities where CNLDO is secondary to, or associated with complex embryonic entities like buried probe, mal-development or non-development of bony NLD, additional proximal lacrimal dysgenesis, atonic sac, or associated craniofacial syndromes and craniofacial dysostosis. The parameters studied include patient demographics, clinical presentation, types of C-CNLDO, management modalities, and outcomes. Success was defined as the subjective resolution of epiphora and discharge with objective measures of normal tear meniscus height and dye clearance on fluorescein dye disappearance test. For patients who underwent a dacryocystorhinostomy (DCR), a minimum follow-up of 1-year post-DCR was considered for outcome analysis.

Of the 2714 cases of CNLDO managed during this period, 482 (17.75%) were diagnosed as complex CNLDO. C-CNLDO showed predilection to the male gender (60.3%, 291/482). A significant number of patients (40.2%, 194/482) presented beyond 36 months of age. The common subtypes of C-CNLDO were atonic sacs (33.8%, 163/482), buried probes (19.7%, 95/482), and associated proximal lacrimal drainage anomalies (11.2%, 54/482). Since C-CNLDO is usually confirmed during the initial endoscopy-guided probing, the managements varied based on the type of C-CNLDO. Silicone intubation and/or balloon dacryoplasty (BDCP), and/or additional minimally invasive procedures were added to the initial endoscopy-guided irrigation and probing based on the nature of C-CNLDO. The overall resolution rate with these non-bypass modalities was 72.6% (350/482). Although the success rates start dropping in C-CNLDO patients beyond 3-years of age, significant success rates with multi-modal (non-bypass) management were noted in age-groups 3-5 years (71.8%, 79/110) and encouraging results (38.5%, 27/70) in 5-10 years age group. The anatomical and functional outcomes in those who underwent endoscopic or external dacryocystorhinostomy with a follow-up beyond 1-year was 96.4% (55/57).

The age at presentation is delayed in patients with C-CNLDO. Multi-modal endoscopy-guided management facilitates the identification of several sub-types of C-CNLDO, and achieves significantly high favourable outcomes in older children. C-CNLDO refractory to probing, intubation and BDCP demonstrates high success with external or endoscopic dacryocystorhinostomy.