Comparison of digital subtraction dacryocystography and dacryoendoscopy in patients with epiphora

Objective To assess the diagnostic information provided by digital subtraction dacryocystography (DCG) and dacryoendoscopy in patients with epiphora. Methods Sixty-eight lacrimal systems of 34 patients with epiphora were prospectively studied. Patients were initially examined with syringing, followed by digital subtraction DCG and dacryoendoscopy to confirm the diagnosis. Obstructions in lacrimal pathways were evaluated by degree, location, and cause. The weighted kappa coefficient was used to compare the agreement between the tests. Results Of the 68 lacrimal pathways, partial or complete obstructions were identified in 56 cases (82.3%) with syringing, in 38 cases (55.9%) with DCG, and in 60 cases (88.2%) with dacryoendoscopy. DCG and dacryoendoscopy showed the same result in 42 of the 68 (61.8%) lacrimal pathways. The weighted kappa value for DCG and dacryoendoscopy was 0.60 (95% CI: 0.40-0.81). The most common sites of obstruction were the common canaliculus (36.7%) and the nasolacrimal duct (28.3%) in dacryoendoscopy. Thirty-three lacrimal pathways (48.5%) were identified to have obstructions on the same level between DCG and dacryoendoscopy. Among the 30 lacrimal pathways (44.1%) that were normal by DCG, obstruction was revealed in 22 cases by dacryoendoscopy, with 11 cases in the common canaliculus. Additional useful information on the cause of obstruction and identification of multiple obstructed sites was provided by dacryoendoscopy. Conclusions DCG and dacryoendoscopy showed moderate agreement in detecting lacrimal pathway obstruction. Dacryoendoscopy allowed for comprehensive investigations of the lacrimal pathway and can help explain unidentified factors associated with lacrimal pathway obstruction in patients with epiphora.