Canaloplasty Improves Successful Positioning of Trabecular Microstent: A Retrospective Comparative Study

Purpose: To evaluate whether preceding Hydrus Microstent implantation with canaloplasty improves the rate of successful device positioning and reduces the incidence of device malposition. Setting: Private glaucoma referral center, United States. Design: Retrospective comparative cohort study. Methods: This study included 368 eyes undergoing phacoemulsification with Hydrus implantation, with or without prior canaloplasty using the OMNI Surgical System. The primary outcome was the rate of successful Hydrus implantation, defined as the absence of both downward tip malposition and intraoperative insertion failure. Complication rates were compared between groups using appropriate statistical analyses. Results: Of 368 eyes, 236 received Hydrus alone and 132 underwent canaloplasty followed by Hydrus. Successful implantation occurred in 206 of 236 eyes (87.3%) in the Hydrus-only group and 124 of 132 eyes (93.9%) in the Canaloplasty + Hydrus group (p = 0.048). Downward tip malposition occurred in 21 of 236 eyes (8.9%) versus 5 of 132 eyes (3.8%), and insertion failure occurred in 9 of 236 eyes (3.8%) versus 3 of 132 eyes (2.3%) in the Hydrus-only and Canaloplasty + Hydrus groups, respectively; these subgroup differences were not statistically significant. However, the downward malposition rate demonstrated a 57% relative risk reduction in the canaloplasty group. Conclusion: Preceding Hydrus implantation with canaloplasty was associated with improved technical delivery success, reflected by reduced downward tip malposition and fewer insertion failures. Canaloplasty was also associated with an unexpected, distinct type of malposition, highlighting the importance of recognizing different malposition patterns and careful intraoperative assessment.