Effects of the silicone tube on the canaliculus: an animal experiment.

A silicone tube is often passed through a fellow normal canaliculus in the treatment of a lacerated canaliculus in order to form a loop in the medial canthus and unite the ends of the tube in the nose. The histopathologic effects of the tube on the canaliculus and the constant frictional trauma caused by movement of the tube with blinking are not known. We intubated both normal and lacerated canaliculi of dogs to determine whether any damage occurred to the normal canaliculus and whether the inflammatory response following surgical repair of canalicular lacerations was prolonged or altered by the tube. We found no significant damage to the normal canaliculus and no increase in the surgical inflammation. Following the repair of a laceration, the canalicular epithelial layer healed along the silicone tube in spite of the constant frictional trauma. These findings support the safety of the use of the silicone tube in the treatment of canalicular disorders.