This study and data collection protocol were approved by the Institutional Review Board of CHA Bundang Medical Center (CHAMC IRB 2018-01-027), and our study design adhered to the tenets of the Declaration of Helsinki. Informed consent about clinical information and specific consent about publication of identifying information/images in an online open-access publication were obtained from each subject before enrollment.
From July 2017 to December 2020, the medical records of patients diagnosed with LDO and underwent MESI were reviewed retrospectively at CHA Bundang Medical Center, Seongnam, South Korea. Eleven patients, 16 eyes were diagnosed LDO and treated with dacryoendoscopy after the CTx and RAI. (Table 1) We carried out vision and intraocular pressure test, slit lamp examination, history taking, canaliculus irrigation test. The severity of epiphora was graded using Munk’s scale. Tear meniscus height, punctal diameter and punctal reserve were measured by OCT (SPECTRALIS®, Heidelberg Engineering, GmbH, Heidelberg, Germany).
The irrigation test was performed by inserting a 26-gauge needle with a blunt tip into a 2mL syringe filled with normal saline solution, inserted into the punctum, and then injected saline to verify that it was passed over to the nose or throat. According to results, it was classified hard stop/soft stop, and well passed/not passed.
Patient who were strongly suspected of LDO proceeded dacryocystography(DCG). DCG was performed after instilled a drop of proparacaine 0.5% (Alcaine; Alcon, TX, USA) into the conjunctival sac, check whether the contrast agent runs along the lacrimal drainage system by injecting the contrast agent, lohexol (Bonorex®; Central Medical Service, Seoul, South Korea) while scanning x-rays. By DCG, we classified primary; narrowing, obstruction and secondary pattern; beaded, dilation.
By measurement of tear meniscus height, irrigation test and DCG, patients were diagnosed with LDO. Patient who underwent systemic CTx or RAI but who did not know the exact drug were excluded. Also we excluded cases that diagnosed with cancer but performed only surgery. Case that underwent additional ophthalmic surgery such as conjunctivochalasis, conjunctival lesion or caruncle lesion were also excluded.
Surgical treatment was done under general anesthesia or local anesthesia by using dacryoendoscopy and inserting a silicon tube, as we call from now on, MESI (microendoscopic silicone tube insertion). After extending the punctum using the punctum extensor and spring scissor, by inserting the 0.9mm diameter probe tip, bent type dacryoendoscope (RUIDO Fibercope, FiberTech Co., Tokyo, Japan) through the punctum, check the internal conditions of the lacrimal duct system by flowing through saline, leading to the upper and lower canaliculus, lacrimal sac, nasolacrimal duct and inferior turbinate.
Dacryoendoscopic findings were classified according to the location and features of obstruction. The obstructive lesion was pushed out by the sheath guided by the endoscopy and pressure of perfusion solution with a syringe connected with probe, and silicone tube insertion was performed from punctum to nasal cavity and fixed with hemolock. Dacryoendoscopic findings were classified into space-occupying and structural changes. The space-occupying group included mucus, stones, and granulation findings; the structural changes group included fibrotic membrane, stenosis, edematous findings.
Surgeries were deemed successful when the patient’s subjective results are satisfied with result, lower tear meniscus height is less than 300μm and the irrigation test was passed after extubation.
Statistical analysis was performed using IBM SPSS software (ver. 26.0; IBM Corp., Armonk, NY, USA). An independent t test and Mann-Whitney test were used to compare parametric and non-parametric groups, respectively. A paired t test was performed to compare before and after surgery data.