In some children the nasolacrimal duct fails to canalise by birth. If so it can lead to recurrent conjunctivitis, and sticky discharge. It will often resolve within the first year, but if not children may be managed by a 'syringe and probe' under GA, in which saline is injected into the punctum to see if the canuli are open, and if not a metal probe is inserted along the canaliculus and then down into the nose