Sectoral excisional goniotomy with Kahook Dual Blade: nasal versus inferior angle treatment

The Kahook Dual Blade (KDB) is a minimally invasive glaucoma surgery (MIGS) device designed to excise a strip of trabecular meshwork, enhancing aqueous outflow via Schlemm's canal. While its efficacy is well-documented, there is limited evidence comparing outcomes between anatomical quadrants treated.

To compare intraocular pressure (IOP) reduction, medication burden, visual acuity improvement, and complication rates between nasal and inferior quadrant sectoral excisional goniotomy with KDB combined with cataract surgery.

Retrospective cohort study.

Medical records of patients with primary open-angle glaucoma who underwent combined phacoemulsification and KDB goniotomy between January 2020 and June 2025 at a single tertiary academic center were reviewed. Patients were grouped by treatment location (nasal vs inferior). Primary outcomes were IOP and the number of glaucoma medications; secondary outcomes included best-corrected visual acuity (BCVA) and adverse events. Multivariate linear regression was used to adjust for baseline differences between groups.

Sixty-four eyes (nasal: 50; inferior: 14) met the inclusion criteria. Baseline IOP and BCVA were similar between groups, though the inferior group had fewer medications (1.93 vs 2.68; p = 0.045) and milder visual field loss (MD -8.39 vs -15.18; p = 0.04). Mean treatment extent was approximately 90° in both groups. Both groups achieved significant IOP reduction at all follow-up points, with no long-term differences. At postoperative week 1, the inferior group had higher IOP (18.50 vs 13.99 mmHg; p = 0.0433), potentially due to gravity-dependent hyphema. Medication burden decreased in both groups, with a non-significant trend toward fewer drops in the inferior group. BCVA improved similarly, and complication rates were low and comparable, with no serious adverse events.

Nasal and inferior quadrant KDB goniotomy combined with cataract surgery yields comparable long-term outcomes in IOP, medication burden, visual acuity, and safety. Quadrant selection may be guided by intraoperative visualization and patient-specific anatomy without compromising efficacy.