A multicenter retrospective comparison of goniotomy versus trabecular bypass device implantation in glaucoma patients undergoing cataract extraction

Purpose: The aim of this study was to compare intraocular pressure (IOP) outcomes in eyes with cataract and glaucoma undergoing phacoemulsification (phaco) in combination with goniotomy using the Kahook Dual Blade (KDB) or implantation of a single iStent trabecular bypass device. Methods: Retrospective analysis of IOP and IOP-lowering medication reduction in eyes undergoing phaco-goniotomy with KDB (n=237) or phaco-iStent (n=198). Preoperative, intraoperative, and postoperative data were collected through 6 months of follow-up. Outcome measures included mean IOP reduction, mean reduction in IOP-lowering medications, and the proportion of eyes achieving >= 20% IOP reduction or >= 1 medication reduction from baseline. Results: Mean IOP in the phaco-goniotomy with KDB group decreased from 17.9 +/- 4.4 mmHg at baseline to 13.6 +/- 2.7 mmHg at Month 6 (P<0.001), with mean medication use decreasing from 1.7 +/- 0.9 to 0.6 +/- 1.0 (P<0.001). In the phaco-iStent group, mean IOP decreased from 16.7 +/- 4.4 mmHg to 13.9 +/- 2.7 mmHg (P<0.001), with mean IOP-lowering medication use decreasing from 1.9 +/- 0.9 to 1.0 +/- 1.0 (P<0.001). Mean IOP reduction from baseline was significantly greater in the phaco-goniotomy with KDB group at Month 6 (phaco-goniotomy with KDB -4.2 mmHg [23.7%] vs phaco-iStent -2.7 mmHg [16.4%]; P<0.001). IOP-lowering medication reduction was greater in the phaco-goniotomy with KDB group compared to the phaco-iStent group (1.1 vs 0.9 medications, respectively; P=0.001). The most common adverse event was IOP spikes occurring in 12.6% of phaco-iStent eyes and 6.3% of phaco-goniotomy with KDB eyes (P=0.024). Conclusion: Goniotomy with the KDB combined with cataract surgery significantly lowers both IOP and the need for IOP-lowering medications compared to cataract extraction with iStent implantation in glaucomatous eyes through 6 months of postoperative follow-up.