Obstruction of nasolacrimal drainage apparatus results in epiphora and can be primary or secondary, congenital or acquired. Obstruction can occur in canaliculi, lacrimal sac, or nasolacrimal duct (post saccular) levels.
Acquired obstruction can be primary (PANDO) or secondary due to a wide range of detectable causes such as trauma and facial fractures, surgery, inflammatory diseases such as sarcoidosis and Wegener's granulomatosis, primary or secondary neoplasms, enlarged ethmoid mucoceles. Secondary acquired obstruction of the canaliculi includes infections, skin burns, drugs for glaucoma, or chemotherapeutic agents such as fluorouracil.
- 1. Russell EJ, Czervionke L, Huckman M et-al. CT of the inferomedial orbit and the lacrimal drainage apparatus: normal and pathologic anatomy. AJR Am J Roentgenol. 1985;145 (6): 1147-54. doi:10.2214/ajr.145.6.1147 - Pubmed citation
- 2. Janssen AG, Mansour K, Bos JJ et-al. Diameter of the bony lacrimal canal: normal values and values related to nasolacrimal duct obstruction: assessment with CT. AJNR Am J Neuroradiol. 2001;22 (5): 845-50. AJNR Am J Neuroradiol (full text) - Pubmed citation