Kahook Dual Blade Goniotomy vs iStent inject: Long-Term Results in Patients with Open-Angle Glaucoma

Figures & data

Table 1 Preoperative Baseline Demographics and Clinical Characteristics in Patients Undergoing Kahook Dual Blade (KDB) Goniotomy or iStent inject Implantation as Sole Procedures (-Alone) or in Combination with Standard Phacoemulsification Cataract Surgery (Phaco-)

Parameters		KDB-Alone	Phaco-KDB	iStent inject-Alone	Phaco-iStent inject	P value
No. of eyes		13	19	14	16
Mean age (years ±SD)		62.0±13.9	66.5±9.0	72.0±12.1	77.7±6.7	0.138
Gender
	Female	7	11	13	10
	Male	6	8	1	6
Glaucoma diagnosis
	POAG	2	9	6	3
	PXG	8	7	5	12
	PDG	2	1
	NTG				1
	OHT	1	2	3
Preoperative lens status
	Phakic	5		5
	Pseudophakic	8		9
Mean BCVA ±SD, logMAR (median)		0.02±0.10 (0.00)	0.14±0.19 (0.10)	0.13±0.15 (0.10)	0.20±0.19 (0.20)	0.034
Mean visual field ±SD, MD (median)		−5.98±3.09 (−5.31)	−6.30±5.44 (−2.75)	−9.34±4.20 (−9.83)	−8.27±4.67 (−7.22)	0.309
Mean IOP ±SD, mmHg		22.2±5.8	24.2±6.8	20.6±5.4	20.9±5.5	0.265
Mean no. of glaucoma medications ±SD		3.2±1.6	2.9±1.6	3.0±1.1	2.9±1.1	0.905

Abbreviations: BCVA, best-corrected visual acuity; IOP, intraocular pressure; NTG, normal-tension glaucoma; OHT, ocular hypertension; PDG, pigment dispersion glaucoma; POAG, primary open-angle glaucoma; PXG, pseudoexfoliative glaucoma; SD, standard deviation.

Figure 1 Intraocular pressure and number of IOP-lowering medications throughout the first 24 months of follow-up with KDB goniotomy and iStent inject implantations, categorized as stand-alone procedures or combined with phacoemulsification cataract surgery (error bars representing SD). A statistically significant IOP-lowering at 24 months compared to baseline was observed in the phaco-KDB and phaco-iStent inject subgroups (P=0.002 and P=0.002, respectively), non-significantly so in the KDB-alone and iStent inject-alone subgroups (P=0.094 and P=0.109, respectively). The phaco-iStent inject subgroup demonstrated a statistically significant lowering of number of glaucoma medications at 24 months (P=0.011) while the KDB-alone, phaco-KDB and iStent inject-alone subgroups did not (P=0.750, P=0.104 and P=0.451, respectively). (A) iStent inject-alone vs phaco-iStent inject implantation; (B) Kahook Dual Blade goniotomy single procedure vs phaco-KDB; (C) iStent inject-alone vs KDB-alone; (D) Phaco-iStent inject vs phaco-KDB.

Note: *P<0.05.

Abbreviations: IOP, intraocular pressure; KDB, Kahook Dual Blade; Meds, number of medications; SD, standard deviation.

Figure 2 Subgroup comparison of IOP reduction (mmHg) from baseline showing the differences between iStent inject-alone, phaco-iStent inject, KDB goniotomy-alone and phaco-KDB. (A) A statistically significant mean IOP reduction (error bars indicating ±SD) at 24 months compared to baseline was observed in the combined KDB and iStent inject subgroups (P=0.002 and P=0.002, respectively); (B) At last follow-up, the KDB-alone (P=0.004), phaco-KDB (P=0.001) and phaco-iStent inject (P=0.003) subgroups all showed a statistically significant mean reduction of IOP while the iStent inject-alone group (P=0.598) failed to do so. Mean follow-up ±SD in brackets.

Note: *P<0.05.

Abbreviations: IOP, intraocular pressure; KDB, Kahook Dual Blade; SD, standard deviation.

Figure 3 Success rates (% of all patients per subgroup) at the target IOP level of <19 mmHg as well as proportional IOP reduction of >20% from baseline to last follow-up, comparing all study subgroups (KDB goniotomy as a single procedure, combined phaco-KDB, iStent inject as a stand-alone procedure and phaco-iStent inject).

Abbreviations: IOP, intraocular pressure; KDB, Kahook Dual Blade.