On reaching the site of the blockage a pseudo punctum is fashioned. A silicone tube is then inserted through the same route. Alternatively canaliculoplasty by closed technique bicanalicular silicone tube insertion can be performed. In cases of failure of the above procedures, a by-pass operation is the only remaining option. It seems that in such cases other underlying causes have been responsible such as punctal phimosis.
Treatment remains controversial.
After identification of the site of blockage an appropriate plan of action should be adopted. Probing of the canaliculi in experienced hands is an effective diagnostic tool. Partial canalicular blockage can be treated by either DCR and silicone tube insertion or by closed technique canaliculoplasty involving bicanalicular insertion of a stent into the naso-lacrimal duct. Extensive canalicular blockage requires more complex surgery. Canaliculo-DCR for distal obstruction and DCR with retrograde intubation for proximal obstruction.