Monocanalicular intubation with Monoka tubes for the treatment of congenital nasolacrimal duct obstruction

Objective: Nasolacrimal duct intubation with Silastic tubes often is used for the treatment of congenital nasolacrimal duct obstruction. The more established intubation technique uses tubing designed for bicanalicular intubation. A commercial product now is available for monocanalicular intubation (Monoka tube, FCl, Issy-Les-Moulineaux Cedex, France), made possible by a punctal anchor attached to the proximal end of the tubing. The authors evaluated the complications and results of their experience with Silastic tube monocanalicular intubation for treatment of congenital nasolacrimal duct obstruction. Design: The study design was a retrospectively reviewed clinical trial with the results compared to a historic cohort treated with an alternative medical device. Participants: Thirty-nine pediatric patients with 48 obstructed congenital nasolacrimal ducts were available for treatment and postoperative follow-up. The historic cohort included 25 cases of congenital nasolacrimal duct obstruction. Intervention: The participants were treated with monocanalicular Silastic tube intubation. The historic cohort was treated with bicanalicular Silastic tube intubation. The tubes were left in place for 4 to 6 months before planned removal. Main Outcome Measures: Dye disappearance tests were performed before and after surgery after removal of the tube. Intraoperative and postoperative complications were noted. Results: Significant complications of the monocanalicular tubing included 1 case of bilateral preseptal cellulitis, 1 case of migration of the punctal anchor into the canaliculus that required surgical correction, 2 cases of a corneal abrasion, 1 case of a corneal ulcer, and 21 cases of premature removal of the tube. Of the 21 cases with premature tube removal, 13 (62%) of the eyes showed an improvement in the symptoms and results of dye disappearance test. Of the 27 cases that completed the full course of tube placement, all the tubes were removed successfully in an office setting, and 25 (93%) showed an improvement in the symptoms and results of dye disappearance test. Significant complications of the authors' bicanalicular intubation include stretching of the punctum, tube dislodgement, and tube removal requiring general anesthesia to the patient. Of the authors' 25 cases treated with bicanalicular intubation, 17 (68%) showed an improvement in the symptoms and results of dye disappearance test. Conclusion: The recently introduced Silastic monocanalicular tubing offers an alternative to bicanalicular tubing for treatment with intubation of congenital nasolacrimal duct obstruction. Complications due to intubation persist with the monocanalicular tube. However, some of the complications the authors encountered may be avoided by a recent change in the design of the tubing and by familiarity with recommended techniques. The overall success rate of 79% with the Monoka tube is lower than that for published reports of bicanalicular intubation.