Nasolacrimal duct obstruction (NLDO) is impaired drainage of tears through the lacrimal system from the punctum, canaliculi, lacrimal sac, into the nasolacrimal duct and nasal cavity. Tears produced by lacrimal gland and accessory glands normally drain via the puncta (upper and lower), canaliculi joining at common canaliculus, into the lacrimal sac, then nasolacrimal duct opening at the inferior meatus through the valve of Hasner.
Classification: Congenital NLDO (CNLDO) affects 5-20% of newborns due to incomplete canalization at the valve of Hasner, with 90% spontaneous resolution by age 1; primary acquired NLDO (PANDO) is most common in postmenopausal women (3-7:1 female:male) due to anatomic narrowing, hormonal effects, age-related fibrosis; secondary acquired causes include trauma (midfacial fractures), infection (chronic dacryocystitis, granulomatous inflammation, sarcoidosis), inflammation (Wegener's, IgG4-related), neoplasm (lacrimal sac tumors, lymphoma, squamous cell carcinoma), iatrogenic (post-sinus surgery, radiation), systemic medications (5-FU, docetaxel, radioactive iodine).
Presentation includes epiphora (constant tearing), mucopurulent discharge especially with sac compression, recurrent conjunctivitis, and acute or chronic dacryocystitis (lacrimal sac inflammation/abscess). Diagnosis: Jones I test (fluorescein recovery from nose), Jones II (irrigation with regurgitation indicates obstruction), dye disappearance test, lacrimal probing/irrigation in office, dacryocystography (radiographic), dacryoscintigraphy (functional), and CT/MRI for tumor or trauma. Endonasal endoscopy assesses the valve of Hasner. Treatment of CNLDO: lacrimal sac massage (Crigler maneuver) and topical antibiotics for infections in first 12 months; probing under general anesthesia after 12 months (success >90% at first probing); silicone intubation for failed probing or older children; balloon catheter dilation for recurrent obstruction. Adult NLDO: external dacryocystorhinostomy (DCR) creates an anastomosis between lacrimal sac and nasal cavity (success >90%), endoscopic endonasal DCR avoids skin scar (success 85-95%), laser DCR less common, conjunctivodacryocystorhinostomy (CDCR) with Jones tube for canalicular obstruction. Acute dacryocystitis: warm compresses, oral antibiotics (amoxicillin/clavulanate, cephalexin), incision and drainage if abscess; definitive DCR after acute resolution. Probiotic intubation for partial obstruction. Tumor evaluation with biopsy if mass, blood-tinged tears, or atypical presentation.