Associated factors of functional failure of external dacryocystorhinostomy

Objective To evaluate the incidence and associated factors of functional failure of anatomically patent external dacryocystorhinostomy (DCR). Design Prospective, nonrandomized case series. Participants Thirty-four consecutive patients who underwent external DCR at the oculoplasty clinic in the Department of Ophthalmology, Seoul National University Hospital between December 2008 and July 2009. Methods All patients underwent external DCR for primary acquired nasolacrimal duct obstruction. The silicone tubes were removed around 6 months after the DCRs, and patients were examined 1 month after tube removal. Anatomical patency was evaluated by a nasal endoscopic dye test and lacrimal syringing test. Tearing symptoms were evaluated using Munk’s scoring system. Patients were divided into 2 groups according to the presence of epiphora symptom; a functional success and functional failure group, and the incidence of functional failure were calculated. Potential associated factors were also compared between 2 groups. Results This study involved 50 eyes of 34 patients, and 8 eyes of 6 patients showed significant epiphora in spite of anatomical patency (16% functional failure). We compared associated factors between 42 functionally successful and 8 functionally failed DCRs. Among variables studied, demographic factors and intraoperative surgical findings were not statistically different between the 2 groups. With respect to intranasal endoscopic findings, the shape of the rhinostomy showed significant differences between the 2 groups (p = 0.03, Fisher’s exact test). In the functional failure group, there were no flat shape rhinostomies. Three showed alcove shape rhinostomies, and the other 5 showed cavern shape rhinostomies. Conclusions Among anatomically patent DCRs, the incidence of persistent epiphora was 16%. The shape of rhinostomy is a possible associated factor for functional failure after external DCR.