The technique and its role of dacryoendoscopy in the management of the false passage of the lacrimal drainage system

This is a retrospective study of patients with primary acquired nasolacrimal duct obstruction (PANDO) who underwent dacryoendoscopy (FT-203F; Fibertech Co., Tokyo, Japan) and sheath-guided silicone intubation for 830 cases with PANDO from March 2016 to December 2020. 19 cases (2.3%) were observed as false passage in the lacrimal drainage system (LDS). Dacryoendoscopic findings revealed that the following factors were associated with LDS obstruction (% cases): structural change of 63.2% (stenosis, 42.1%; fibrotic membrane, 21.1%), and secretory change of 36.8% (mucus, 15.8%; stone, 10.5%; and granulation, 10.5%). The obstruction sites were distributed through LDS. The false passages detected in LDS were managed as follow: usage of fluid irrigation pressure to check the true passage following the previously intubated silicone tube as a reference, and confirmation the end of passage through the inferior meatus with nasal endoscopy. The overall success rate was 73.7% using this management technique. Dacryoendoscopy enables real-time observation of the lumen of the LDS, thus facilitating management of pathological lesions including false passages. With this technique, we are better able to make customized treatment of patients with false passages, with a safer and more effective results leading to the success of dacryoendoscopy guided silicone tube intubation in PANDO patients.