nasolacrimale

Nasolacrimale refers to the nasolacrimal drainage system, the anatomical pathway that carries tears from the ocular surface into the nasal cavity. The main components are the lacrimal gland and tear film, the lacrimal puncta at the inner corners of the eyelids, the superior and inferior canaliculi, the lacrimal sac, and the nasolacrimal duct. The duct runs from the lacrimal sac through surrounding bone to open into the inferior meatus of the nasal cavity, typically near the inferior nasal concha. The distal end of the duct features the Hasner valve, which helps regulate tear outflow into the nose.

Physiology and function depend on the coordinated action of tear production, distribution, and drainage. Tears are produced by the lacrimal gland and spread across the ocular surface during blinking, forming a tear film with lipid, aqueous, and mucous layers. Excess tears are collected by the puncta, pass through the canaliculi into the lacrimal sac, and drain via the nasolacrimal duct into the nasal cavity. The system helps keep the ocular surface moist and clear of debris.

Clinical relevance includes nasolacrimal duct obstruction (NLDO), a condition that can be congenital or acquired. In infants, NLDO often presents with excess tearing (epiphora) and may spontaneously resolve within the first year. In adults, NLDO may result from inflammation, infection, trauma, or chronic rhinosinusitis and can cause persistent tearing and recurrent infections. Diagnosis commonly involves lacrimal irrigation, dye tests, and imaging such as dacryocystography.

Treatment ranges from conservative management in infants—such as nasolacrimal sac massage and monitoring—to surgical intervention in persistent cases. The standard adult procedure is dacryocystorhinostomy (DCR), sometimes combined with silicone stenting or balloon dilation of the duct.