Possibility of Pseudo-Obstruction in Lacrimal Canalicular Obstruction Diagnosed with Dacryocystography.

INTRODUCTION Endoscopic dacryocystorhinostomy (DCR) is the treatment of choice for patients with lacrimal drainage system obstruction. Dacryocystography (DCG) is one of the most common preoperative studies and considered as a useful test demonstrating the anatomy of lacrimal drainage systems. OBJECTIVE This study was designed to evaluate the diagnostic efficacy of DCG for canalicular obstruction and to compare surgical outcomes between true-obstruction versus pseudo-obstruction diagnosed with DCG. METHODS A retrospective study was performed on 45 consecutive patients with lacrimal canalicular obstruction who had underwent endoscopic DCR with silicone tube insertion from January 2009 to December 2014 at a single tertiary hospital. A review of medical records included demographic data, preoperative symptoms and signs, results of intraoperative canalicular probing, and surgical outcomes including the postoperative symptom improvement and endoscopic finding. RESULTS Of 45 patients, 34 patients (75.6%) had true-canalicular obstructions and 11 patients (24.4%) had pseudo-canalicular obstructions. The success rate of endoscopic DCR was 50% (17 of 34) in cases with true-canalicular obstruction while 90.9% (10 of 11) in pseudo-canalicular obstruction (p value <0.05). No intraoperative or postoperative complications including sinusitis or synechia were found. CONCLUSIONS About a quarter of lacrimal canalicular obstruction cases diagnosed with DCG seem to be pseudo-obstruction. The success rate of endoscopic DCR in pseudo-canalicular obstruction is similar to that of saccal and nasolacrimal ductal obstruction.