Lacerated tear ducts can be quickly and accurately repaired with a minimum of trauma and a good functional result by a method based on localization of the distal side of the lacerated canaliculus by injection of air into the lacrimal sac. The air is injected by way of the intact canaliculus on the same side. Before injection of air, the nasolacrimal ostium in the nose is blocked in order to form a closed system except at the point of laceration where the air can escape.
Before the area is surgically prepared, the anterior end of the inferior turbinate is exposed with a nasal speculum so that a cotton tampon can be inserted into the inferior meatus. This tampon closes off the nasal end of the nasolacrimal duct, the ostium lacrimal. The ostium is usually about 15 mm behind the leading margin of the inferior turbinate and about the same distance
MORRISON FD. An Aid to Repair of Lacerated Tear Ducts. Arch Ophthalmol. 1964;72(3):341-342. doi:10.1001/archopht.1964.00970020341010