Nasolacrimal duct obstruction is common in the first year of life and usually resolves spontaneously. It causes eye watering and recurrent infections of the lacrimal sac and conjunctiva especially when the child has a cold, when the partial obstruction to lacrimal drainage is excarcerbated by swelling of the mucosa that lines the drainage tract.
When watering fails to improve after one year, syringing and probing of the nasolacrimal duct is recommended. This requires a general anaesthetic and has been reported to have a success rate of 79% for children between 1 and 3 years and of 56% for children between 3 and 4. (Pediatric Eye disease Investigator Group, Ophthalmology March 2008). The success rate for probing in patients was lower for those with bilateral disease (adjusted relative risk 0.88). These children may have more significant anatomical variations in the nasolacrimal duct.