Efficacy of Goniotomy With Kahook Dual Blade in Patients With Uveitis-associated Ocular Hypertension

Abstract

Precis: In a small case series of patients with uveitis-associated ocular hypertension (OHTN) or glaucoma, goniotomy with Kahook Dual Blade (KDB) was an effective surgical treatment option for lowering intraocular pressure (IOP). Purpose: The purpose of this study is to review the success of goniotomy using the KDB with trabecular meshwork (TM) excision in lowering the IOP of patients with uveitis-associated OHTN or glaucoma. Materials and Methods: A retrospective chart review was completed for all patients with uveitis-associated OHTN or glaucoma who underwent KDB goniotomy with TM excision alone or in combination with phacoemulsification cataract surgery at a single institution. The study included 12 patients (16 eyes). Patients were followed for a minimum of 5 months postoperatively. The main outcome measures of this case series included postoperative IOPs, percent IOP reduction, and reduction of glaucoma medications. Results: The mean maximum IOP of the patients before maximum-tolerated medical therapy or surgery was 35.6±5.8 mm Hg. The mean preoperative IOP at the clinical office visit before surgery of these patients was 28.1±8.5 mm Hg on maximum-tolerated medical therapy. Ten eyes (62.5%) have maintained an IOP at or below their goal through their most recent follow-up visit (mean follow-up time of 9.6±5.6 mo). The mean number of glaucoma medications was significantly reduced from 3.6±0.9 medications to 2.1±1.7 medications, for a mean reduction of 1.5±1.4 medications (P=0.004). Conclusions: On the basis of this small case series, KDB goniotomy may be a safe, less invasive, and effective first-line surgical alternative for patients with uveitis-associated OHTN or glaucoma refractory to medical therapy.

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

“…The iStent is labeled for use in eyes with mild to moderate OAG,3 while KDB excisional goniotomy can successfully lower IOP across the spectrum of severity including advanced OAG 6–10. The KDB is also effective in challenging secondary glaucoma such as angle-closure9,10 and uveitic glaucoma,11 and in contrast to the iStent’s label, KDB excisional goniotomy can be performed as a standalone procedure 6…”

“…The Kahook Dual Blade (New World Medical, Rancho Cucamonga, CA) is a surgical knife designed to excise a strip of TM in a procedure known as excisional goniotomy. The procedure can be performed at the time of cataract surgery or as a standalone procedure,6 is effective in mild to advanced OAG,6–9 and has been performed successfully in secondary glaucomas as well 9–11. In clinical studies, KDB-Phaco lowered IOP by ~25% and medications by ~45–65% 7,10,12,13.…”

Microinvasive Glaucoma Surgery: An Evidence-Based Review

“…[26][27][28] When the uveitic glaucoma patients with elevated IOP were studied, only about 38% of them achieved the 20% reduction mark. 29 Although the retrospective studies referenced above focus on KDB as a standalone procedure, KDB has been shown to be similarly effective with cataract surgery. Using the 20% IOP reduction mark as a success standpoint, phaco/KDB demonstrated that 72% of the eyes had ≥20% IOP reduction, which was not statistically different from KDB alone in which 69% had ≥20% IOP reduction.…”

“…24,26,27,30 In terms of medication reduction, as a standalone procedure, KDB may reduce medications by 0-1, and phaco/KDB may reduce medications by 0.1-2.1 in glaucoma of all types and severities. 23,24,[28][29][30] In general, the severity and type of glaucoma have not been significantly correlated with KDB success rates, although most studies were done in mild-to-moderate glaucoma or OHTN patients. 28,30 KDB has been shown to be effective in severe/ refractive OAG and ACG, reducing IOP by up to 24% in these patients.…”

“…The most common complication of KDB was hyphema, which occurred 6%-19% of the time, with the majority resolving by postoperative month 1. 23,24,[26][27][28][29][30] Another complication was surgical failure, with patients requiring further glaucoma surgery in 4%-25% of the cases. 23,24,[26][27][28][29][30] The surgical failure rate appears to be highest in the uveitic group.…”