(b) The mucous nasolacrimal duct and the lacrimal sac are elevated from the bony nasolacrimal canal and the orbital periosteum. The nasolacrimal duct is then severed at the lower end.

Using a metal cannula may damage the lacrimal sac and nasolacrimal duct; a safer alternative is a soft Teflon catheter (Fig. 2). Trauma can result in scar tissue formation, which can result in ...