Fig. (1) Schematic illustration of Crawford tubes manipulation.A) Crawford tubes with intraluminal suture applied to the lacrimal puncta (not visualized) that prevents obstruction by debris and mucus B) Knotting of the free distal ends of the tube C) Shortening of the tubes (approximatively 10 mm of length from the distal end of the lacrimal canaliculi) D) anchorage of the knotted tubes to the posterolateral portion of the lacrimal fossa mucosa.