Nasolacrimal Duct Obstruction

This prospective, single-arm interventional clinical study aims to evaluate the short- and intermediate-term anatomical, functional, and quality-of-life outcomes of primary stentless endoscopic dacryocystorhinostomy (En-DCR) in adult patients with primary acquired nasolacrimal duct obstruction (PANDO). Endoscopic DCR bypasses the obstructed distal lacrimal drainage pathway by creating a permanent communication between the lacrimal sac and the nasal cavity. While silicone intubation is traditionally used to prevent early restenosis, its routine use remains controversial due to potential foreign-body morbidity, including canalicular trauma, granuloma formation, tube displacement, and the necessity for a secondary removal procedure. The rationale for this study is based on the concept that surgical success is determined by adequate osteotomy, wide sac marsupialization, mucosal flap preservation, and structured postoperative care, rather than the presence of a permanent foreign body. The study will recruit approximately 40 eligible adults (aged $\\ge$16 years) with objectively confirmed, symptomatic PANDO to undergo a standardized stentless En-DCR procedure. Participants will undergo rigorous postoperative clinical and endoscopic assessments at 1 week, 1 month, 3 months, 6 months, and 12 months. The primary endpoint is the overall composite success rate at 12 months, defined by both objective anatomical patency of the rhinostomy (verified via endoscopy and lacrimal irrigation) and clinically meaningful functional resolution of epiphora (Munk score 0-1). Secondary objectives include quantifying changes in disease-specific quality of life using the Lac-Q questionnaire, documenting postoperative endoscopic healing parameters, and evaluating the incidence and mechanisms of surgical failure or complications.

The association of radioiodine therapy for the treatment of thyroid cancer with nasolacrimal duct obstruction has been well documented in the medical literature. Prior case reports have documented radioactive iodine detection in the tears of patients following radioiodine therapy. It is possible that radioactive uptake by the cells in the lacrimal sac and nasolacrimal duct lead to inflammation, fibrosis, and obstruction of the tear duct over time. A recent study has shown that the administration of artificial tears decreases the level of detectable radioiodine in the tears of patients undergoing radioiodine therapy for thyroid cancer. The purpose of this study will be to assess whether administering tears after radioactive iodine therapy for thyroid cancer decreases the incidence of nasolacrimal duct obstruction in the two years following radioactive iodine treatment.

Congenital nasolacrimal duct obstruction (CNLDO) is a common ophthalmic condition in children, presenting with tearing and pus overflow, with a prevalence of 5%-20% within 1 year of age. Although most cases resolve spontaneously within 1 year of age, some children require treatment. Lacrimal sac massage is a non-invasive, easy and cost-effective conservative treatment that helps to unblock the obstruction by increasing the pressure in the tear duct. Studies have shown that massage has a 93% cure rate in children under 8 months of age. In contrast, tear duct probing is effective but invasive and risky. In recent years, with the development of minimally invasive techniques, lacrimal sac massage has received renewed attention, and studies have shown its efficacy to be comparable to probing. However, there are problems of non-standardized massage timing and techniques in clinical practice, which affects the therapeutic efficacy. This study aims to assess whether the efficacy of standardized dacryocystic massage is not inferior to that of dacryocystorhinostomy through a randomized controlled trial, providing a reference for the treatment of CNLDO.