The Factors That Affected the Outcome of Treatment of Congenital Nasolacrimal Duct Obstruction

"A punctal dilator was used for dilating the punctum. The nasolacrimal system was irrigated through either the lower or upper punctum with a hollow 23-gauge irrigating cannula attached to a syringe. A #0 (or #00) Bowman probe was passed through either the lower or upper canaliculus into the lacrimal sac and then directed downward through the nasolacrimal duct into nasal cavity. A Hard resistance could be felt as the probe touched the end of the nasolacrimal duct. A Pop tactile sensation might be noted while the probe passing through an obstruction at the valve of Hasner."