A clinical trial of endoscopic vs external dacryocystorhinostomy for partial nasolacrimal duct obstruction

Abstract

A literature review revealed there is no outcome data for endoscopic endonasal dacryocystorhinostomy (EES-DCR) in the subgroup of patients with acquired partial nasolacrimal duct obstruction (NDO). This study aimed to compare the results of EES-DCR vs external DCR (ext-DCR) in the treatment of partial NDO. This study is designed as a prospective nonrandomised comparative clinical trial. In total, 46 adult patients with acquired partial NDO participated in this study. Partial (sometimes called 'functional') NDO (epiphora in the presence of patent syringing) was confirmed by nuclear lacrimal scintigraphy or delayed drainage on dacryocystography. Patients with 'functional' epiphora from other causes were excluded. Post-operative outcome was assessed at 6 months. Overall, 21 (46%) patients had EES-DCR and 25 patients had (54%) ext-DCR. Subjective success was based on patient symptoms, objective success on patency with syringing and a functioning rhinostomy evaluated using the functional endoscopic dye test (FEDT). In total 18 out of 21 (86%) of EES-DCR patients had marked reduction (n=11) or complete resolution (n=7) and 25 out of 25 (100%) of ext-DCR had marked reduction (n=9) or complete resolution (n=16) of epiphora. In total 17 out of 18 (94%) of the EES-DCR patients with subjective success had a positive FEDT. All 25 out of 25 (100%) ext-DCR patients with subjective success had a positive FEDT. The three failed EES-DCR patients were all blocked on syringing. Statistically, EES-DCR does not achieve the same success rate as ext-DCR in this study (P=0.09, two-tailed Fisher's exact test, 0.045 one-tailed). Both endoscopic and external DCRs provide satisfactory outcomes in acquired partial NDO. The success rate is nevertheless higher in ext-DCR compared with EES-DCR.