tears (defective drainage, eye)
This describes excessive tearing due to defective drainage of tears through the lacrimal passages.
Major causes include:
- facial palsy - orbicularis oculi muscle weakness which impairs the pumping action of the canaliculi
- punctal malposition - ectropion
- punctal occlusion - congenital absence, scarred, blockage e.g. due to chronic infection with staphylococcus or herpes simplex, or following chronic drug administration
- canalicular obstruction secondary to canaliculitis
- nasolacrimal duct obstruction
The patency of the lacrimal system should be explored to assess the precise cause of the epiphora. Careful inspection will reveal an ectropion or punctal occlusion. Probing and syringing of the lacrimal passages will reveal obstruction in the canaliculus or the nasolacrimal duct; the site may be precisely delineated by contrast radiography - dacryocystography. In infants, the patency of the nasolacrimal duct may be explored by syringing.
Last reviewed 01/2018