External dacryocystorhinostomy (DCR). A, The incision is marked 10 mm from the medial canthus, starting just above the medial canthal tendon and extending inferiorly. B, Bone from the lacrimal fossa and anterior lacrimal crest has been resected. Flaps have been fashioned in the nasal mucosa. A lacrimal probe extends through an incision in the lacrimal sac. C, The anterior lacrimal sac flap is sutured to the anterior nasal mucosal flap after a silicone tube is placed. D, Final position of the silicone tube following closure of the skin incision.