Bicanalicular silicone intubation using three-piece silicone tubing: direct silicone intubation

The special silicone tube (50-120 mm in length) consists of three pieces. One piece is the thinner central segment [20-40 mm long, 0.64 mm outer diameter (OD), 0.30 mm inner diameter (ID)], and the other two are thicker bilateral segments (10-50 mm long, 0.94 mm OD, 0.51 mm ID). Both ends of the three-piece silicone tubing (TPST) were sealed by the silastic medical adhesive with or without the silicone rod (2 mm long, 0.5 mm diameter) and diagonally cut to taper the end. To push the TPST from the upper and lower puncta into the lacrimal passage, a thin metal probe (0.4-0.6 mm diameter) was inserted into both sides of the tube through a small cut. In this new technique, there is no difficult procedure of retrieving the tip of a metal probe from the nasal cavity. The TPST requires no suture to secure it in position. The success rates were 63.6% (7/11), 100% (5/5) and 50% (1/2) for nasolacrimal-duct obstruction, canalicular obstruction, and canalicular and nasolacrimal-duct obstructions, respectively (follow-up: 3.4-12 months, mean 5.3 months).