Outcomes and risk factors for Kahook Dual Blade excisional goniotomy with concomitant phacoemulsification: a multicentre Canadian study

Objective: To assess the outcomes and failure risk factors for Kahook Dual Blade (KDB) excisional goniotomy with cataract surgery (phaco-KDB) in eyes with various glaucoma subtypes and severities. Methods: This multisurgeon consecutive case series included glaucomatous eyes with cataract that underwent phaco-KDB and had a minimum follow-up of 12 months postoperatively. Efficacy was assessed by absolute and qualified surgical success (defined by different criteria) and changes in intraocular pressure (IOP) and antiglaucoma medication (AGM) at the last postoperative follow-up. Safety included best- corrected visual acuity, cup-to-disc ratio, visual field mean deviation, retinal nerve fibre layer thickness, and adverse events. Results: A total of 108 eyes of 89 patients with a median follow-up of 18 months (range, 12-47 months) were included. IOP decreased by 26% from 19.1 f 5.0 mm Hg to 14.1 f 3.5 mm Hg (p < 0.001), AGM use decreased by 29% from 2.4 f 1.3 medications to 1.7 f 1.3 (p < 0.001), and 25% of eyes became free of AGMs (vs 3% at baseline). Qualified success rates achieved for IOP cutoffs of 18, 15, and 12 mm Hg were 87%, 68%, and 46%, respectively. Higher baseline IOP and postoperative incidence of IOP spikes were associated with a higher risk of surgical failure. Best-corrected visual acuity improved postoperatively (p < 0.001), and visual field mean deviation, cup-to-disc ratio, and retinal nerve fibre layer thickness remained stable. Overall, safety was favourable, and adverse events were transient and not sight threatening. Conclusion: This multicentre Canadian study provides real-world data that support the safety and efficacy of phaco-KDB in reducing IOP and AGM use with no evidence of disease progression during the follow-up period.