An animal model studying reconstruction techniques and histopathological changes in repair of canalicular lacerations

We designed an animal model using sheep to evaluate three methods of canalicular reconstruction after laceration: direct sutured reapposition of the canaliculus without silicone intubation (4 eyelids), silicone intubation of the canalicular system without mucosal anastomosis (14 lids) and silicone intubation with mucosal anastomosis (10 lids). We also wished to determine the appropriate time of silicone tube removal. In the canaliculi repaired using silicone intubation the tubes were removed at 4, 8 or 12 weeks. Patency of the canalicular system was assessed at 16 weeks by probing. Sections of eyelid tissue were examined histopathologically to confirm patency and to compare the tissue alteration caused by the various methods of repair. We found that silicone intubation was necessary to reestablish patency of the canaliculus and that silicone intubation with and intubation without mucosal anastomosis were equally efficacious in restoring canalicular patency. The optimum time for removal of the tube was 12 weeks. Histopathologically, all canaliculi found to be patent by probing demonstrated mucosal continuity along the canalicular lumen.