[Diagnosis and management of congenital nasolacrimal duct obstruction].

Congenital nasolacrimal duct obstruction (CNLDO) represents the most prevalent cause of epiphora in infancy, with a reported incidence of approximately 6-20% of newborns. In the majority of cases, a membranous occlusion at the valve of Hasner is responsible, with spontaneous resolution occurring in up to 96% within the first year of life.Clinical signs comprise persistent tearing, an elevated tear meniscus and recurrent mucopurulent discharge; digital pressure on the lacrimal sac may induce retrograde reflux. Ophthalmic examination is indispensable to exclude differential diagnoses such as congenital glaucoma, keratoconjunctivitis or eyelid malposition.Given the high probability of spontaneous resolution, conservative management is the treatment of choice during the first 6-12 months of life, including parental instructions, consistent lid hygiene, and lacrimal sac massage. Topical antibiotics should be restricted to short-term application in the presence of bacterial superinfection.In cases of persistent obstruction or complicated disease lacrimal probing is indicated, usually after 12 months of age in general anaesthesia. Silicone intubation is recommended for complex or recurrent obstructions, failed probing, or in older children, and associated with substantially improved success rates. Endoscopic techniques including transcanalicular dacryoendoscopy, ballon dacryoplasty, and endonasal endoscopy can be helpful in refractory and anatomically complex cases. Dacryocystorhinostomy serves as ultima ratio surgery in treatment-refractory or bony stenosis and should not be performed before the age of one year.A staged, evidence-based therapeutic management beginning with conservative measures and escalating to age- and anatomy-adapted interventions, is recommended to achieve favourable outcomes.