Comparison of Efficacy of Combined Phacoemulsification and iStent Inject versus Combined Phacoemulsification and Hydrus Microstent

Aim: This study aims to compare the efficacy and safety of combined phacoemulsification with iStent inject (Phaco-iStent) and Hydrus microstent (Phaco-Hydrus). Methods: This was a retrospective comparative study of patients who underwent Phaco-iStent from April 2019 to August 2020 and Phaco-Hydrus from August 2019 to December 2020 at a tertiary eye centre in Singapore. Sixty-nine Phaco-iStent eyes and 49 Phaco-Hydrus eyes were included in this study. Complete surgical success was defined as freedom from second glaucoma surgery, Intraocular pressure (IOP) of 18 mmHg or less, and discontinuation of all antiglaucoma medications. Results: At 12 months, both Phaco-iStent and Phaco-Hydrus groups had comparable surgical success rate (68.1% vs 51%, p=0.061), reduction in antiglaucoma medication use (-1.3 +/- 0.1 vs -1.4 +/- 0.10, p=0.880) and intraocular pressure reduction (-1.1 +/- 0.5 mmHg vs -1.6 +/- 0.9 mmHg, p=0.323). Overall intraoperative and postoperative complications rate were similar in both groups, though hyphema was more commonly seen in early postoperative period in the Phaco-Hydrus compared to the Phaco-iStent group (8% vs 0%, p=0.028), with majority of cases resolving without any need for surgical intervention. Device obstruction was also more common in the Phaco-Hydrus group compared to the Phaco-iStent group (14% vs 4.3%, p=0.04). Conclusion: Phaco-iStent and Phaco-Hydrus have similar surgical efficacy and safety profiles at 12 months.