Comparison Of Surgical Outcomes Between Excisional Goniotomy Using The Kahook Dual Blade And iStent Trabecular Micro-Bypass Stent In Combination With Phacoemulsification

Purpose: To compare 6-month surgical outcomes of patients who underwent phacoemulsification (Phaco) combined with iStent implantation (iStent) versus excisional goniotomy using Kahook Dual Blade (KDB).

Methods: Retrospective comparative case series of 58 iStent-Phaco eyes and 44 KDB-Phaco eyes operated upon by a single surgeon between 2016 and 2018. Preoperative, intraoperative, and postoperative intraocular pressure (IOP) and IOP-lowering medication data were collected. The primary outcome was the proportion of eyes using ≥1 fewer IOP-lowering medication at Month 6 while maintaining IOP ≤ 18 mmHg.

Results: Baseline IOP was 17.2 (standard error 0.7) in the KDB-Phaco group using a mean of 1.9 (0.2) medications; at Month 6, mean IOP was 14.8 mmHg P=0.002) on 1.0 (0.2) medications (P<0.002). Baseline IOP was 16.7 (0.4) in the iStent-Phaco group using a mean of 1.4 (0.1) medications; at Month 6, mean IOP was 14.2 mmHg (P<0.002) on 1.4 (0.1) medications P=0.374). Changes in IOP and medications were not significantly different between groups (P>0.05). Significantly more KDB-Phaco eyes than iStent-Phaco eyes (43.2% vs 17.2%, P=0.004) were using ≥1 fewer medications while maintaining IOP ≤18 mmHg at Month 6. Adverse events were uncommon and similar in nature and frequency between groups with the exception that more KDB-Phaco eyes than iStent-Phaco eyes (8 [18.2%] versus 1 [1.7%]) experienced an IOP elevation presumed to be related to steroid use.

Conclusion: KDB-Phaco and iStent-Phaco provided comparable IOP and medication reductions. The proportion of eyes able to discontinue 1 or more medications while maintaining IOP ≤ 18 mmHg was significantly greater in eyes undergoing KDB-Phaco.