Reduction of Intraocular Pressure after Use of a Novel Goniotomy Blade Combined with Phacoemulsification

Abstract

Purpose : The Kahook Dual Blade (KDB, New World Medical Rancho Cucamonga, CA) is a single-use goniotomy knife designed to make parallel incisions in the trabecular meshwork allowing aqueous humor unimpeded access to collector channels. The study's purpose was to assess the IOP lowering efficacy of combined KDB and phacoemulsification (PE). Reduction of dependence on IOP lowering medications as well as the safety profile of the procedure was also assessed.

Methods : This was a prospective consecutive case series of patients undergoing combined KDB goniotomy and PE with participation from eight surgeons at six surgical centers in the United States and one in Mexico. Glaucoma type and severity, glaucoma medications, and baseline pretreatment IOP were collected on the operative day. Adverse events (AE) were collected on the operative day and on each subsequent visit. Each surgeon also completed an ease of use questionnaire after each case. Changes in IOP and dependence on glaucoma medications from baseline were analyzed using mixed models.

Results : Data were collected on 71 eyes of which 70% had primary open angle glaucoma, 17% chronic angle closure glaucoma, 6% pigmentary glaucoma and 3% pseudoexfoliation glaucoma. 35% and 23% of the eyes were assessed as severe and moderate glaucoma respectively. In 96% of cases, surgeons either strongly agreed or agreed that KDB use was straightforward, entry into the canal of Schlemm was uncomplicated and advancement along the treatment pathway was smooth. In 75% of eyes, blood reflux was observed intraoperatively, indicating a patent distal outflow pathway. At 12 months, IOP was significantly reduced to 12.4±2.6 mmHg compared to 17.4±1.6 at baseline (P<0.001). Glaucoma medication burden was also significantly reduced to 0.9±1.0 at 12 month from 1.6±1.3 at baseline (p=0.001). The most common AE was retained anterior chamber blood in 3.4% of eyes at 1 week. There was one case each of iridodialysis, clyclodialysis and a small descemet tear, none of which required treatment or resulted in deterioration of vision.

Conclusions : KDB+PE resulted in statistically significant reduction of IOP and dependence on glaucoma medications after 12 months of follow-up. The KDB treatment was safe with a short learning curve. Further data collection is ongoing to help understand the IOP lowering efficacy of KDB when combined with cataract extraction beyond one year of follow-up.

This is an abstract that was submitted for the 2017 ARVO Annual Meeting, held in Baltimore, MD, May 7-11, 2017.