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Dacryostenosis is obstruction or stenosis of the nasolacrimal duct, causing excess tearing.
Nasolacrimal obstruction may be congenital or acquired. One cause of congenital obstruction is inadequate development of any part of the nasolacrimal ducts. Typically, a membrane at the distal end of the nasolacrimal duct persists. There is tearing and purulent discharge; the condition may manifest as chronic conjunctivitis, usually beginning after the age of 2 wk (most often at age 3 to 12 wk).
There are many causes of acquired nasolacrimal duct obstruction (see Table: Causes of Acquired Nasolacrimal Duct Obstruction). The cause is most often age-related stenosis of the nasolacrimal duct. Other causes include past nasal or facial bone fractures and sinus surgery, which disrupt the nasolacrimal duct; inflammatory diseases (eg, sarcoidosis, granulomatosis with polyangiitis [formerly Wegener granulomatosis]); and dacryocystitis (see Dacryocystitis).
Causes of punctal or canalicular stenosis include chronic conjunctivitis (especially herpes simplex), certain types of chemotherapy, adverse reactions to eye drops (especially topical echothiophate iodide), and radiation.
Congenital nasolacrimal duct obstruction often resolves spontaneously by about age 6 to 9 mo; before 1 yr, manual compression of the lacrimal sac 4 or 5 times/day may relieve the obstruction. After age 1 yr, the nasolacrimal duct may need probing, usually under general anesthesia; if obstruction is recurrent, a temporary silastic tube may be inserted.
In acquired nasolacrimal duct obstruction, the underlying disorder is treated when possible. If treatment is not possible or is ineffective, a passage between the lacrimal sac and the nasal cavity can be created surgically (dacryocystorhinostomy).
In cases of punctal or canalicular stenosis, dilation is usually curative. If canalicular stenosis is severe and bothersome, a surgical procedure that places a tube made of low thermal-expansion borosilicate glass (Jones tube) leading from the caruncle into the nasal cavity can be considered.
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