XEN glaucoma treatment system in the management of refractory glaucomas: a short review on trial data and potential role in clinical practice

Figures & data

Figure 1 (A) XEN gel stent; (B) preloaded injector and correct handling.

Figure 2 (A) MMC subconjunctival injection; (B) massage; (C) hydroexpansion.

Abbreviation: MMC, mitomycin C.

Figure 3 Sequence of XEN45 gel stent implant (A–D).

Figure 4 Correct implantation of XEN45 gel stent (2.0 mm of exposed implant in the subconjunctival space, 1.0 mm in the anterior chamber, and 3.0 mm tunneled through sclera).

Table 1 Outcomes of published studies at 12-month follow-up

Author, year	Study design	XEN model ± MMC	Eye number	Previous glaucoma surgery, %	% IOP reduction	Patients off medications after XEN, %	% medication classes reduction	Needling rate, %
Sheybani et al,^Citation13 2015	Prospective	XEN140 and XEN63	37	None	32.25	50	64	32
Sheybani et al,^Citation14 2016	Prospective	XEN140	49	45	36.4	42	56.6	43
Pérez-Torregrosa et al,^Citation15 2016	Prospective	XEN45 + MMC	30	None	29.34	90	94.57	None
De Gregorio et al,^Citation12 2017	Prospective	XEN45 + MMC	41	2.4	41.82	80.4	84	2.4
Schlenker et al,^Citation16 2017	Retrospective	XEN45 + MMC	185	None	45.83	74.9	Not specified	43.2
Grover et al,^Citation17 2017	Prospective	XEN45 + MMCa	65	84.6	35.6	38.5	51.42	32.3
Galal et al,^Citation18 2017	Prospective	XEN45 + MMC	13	None	29.4	42	94.57	30.7

Notes: MMC: pretreatment with MMC injected in the subconjunctival space.

a MMC pretreatment with sponges after conjunctival incision.

Abbreviations: IOP, intraocular pressure; MMC, mitomycin C.

Table 2 Postoperative complications correlated to XEN45 implant reported in published studies

Postoperative complications	Author, year
	Sheybani et al,^Citation13 2015	Sheybani et al,^Citation14 2016	Pérez-Torregrosa et al,^Citation15 2016	De Gregorio et al,^Citation12 2017	Schlenker et al,^Citation16 2017	Grover et al,^Citation17 2017	Galal et al,^Citation18 2017	Prokosch-Willing et al,^Citation19 2017
Additional glaucoma surgery	–	3 (6.1%)	–	1 (2.4%)	19 (10.3%)	7 (10.7%)	2 (15.3%)	–
Requiring needling	12 (32%)	21 (43%)	–	1 (2.4%)	79 (43.2%)	21 (32.3%)	4 (30.7%)	–
Corneal edema	–	–	–	–	–	1 (1.5%)	–	–
Choroidal detachment (transient)		–	–	–	–	–	2 (15.3%)	–
Choroidal effusion	–	–	–	–	–	–	–	–
Choroidal folds	–	–	–	–	1 (0.5%)	–	–	–
Dellen	–	–	–	–	2 (1.08%)	1 (1.5%)	–	–
Device explant	–	–	–	1 (2.4%)	–	1 (1.5%)	1 (7.7%)	–
Device extrusion	–	–	–	–	1 (0.5%)	1 (1.5%)	1 (7.7%)	–
Device migration	–	–	–	1 (2.4%)	–	1 (1.5%)	–	–
Device obstruction	–	–	–	1 (2.4%)	1 (0.5%)	–	–	–
Flat AC requiring AC refill	2 (5.4%)	4 (9%)	–	–	–	1 (1.5%)	–	–
Hyperhemia	–	–	–	–	–	1 (1.5%)	–	–
Hyphema	–	–	–	–	2 (1.08%)	3 (4.6%)	–	–
Hypotony maculopathy	–	–	–	–	2 (1.08%)	–	–	–
Malignant glaucoma	–	–	–	–	4 (2.1%)	–	–	–
Microstent-iris touch	–	–	–	–	2 (1.08%)	1 (1.5%)	–	–
Transient hypotonia <6 mmHg	13 (35.1%)	–	–	1 (2.4%)	–	16 (24.6%)	2 (15.3%)	–
Persistent hypotony >1 month	–	–	–	–	–	–	–	–
Suprachoroidal bleeding	–	–	–	–	–	–	–	1a
Transient choroidal detachment	–	–	–	1 (2.4%)	–	–	–	–
Uveitis/AC cells	–	–	–	–	2 (1.08%)	2 (3.1%)	–	–
Vitreous hemorrhage	–	–	–	–	2 (1.08%)	–	–	–
Wound leak	–	–	–	–	3 (1.6%)	6 (9.2%)	–	–

Notes:

a Complication reported in a case report. “–” indicates no data.

Abbreviation: AC, anterior chamber.

Figure 5 XEN45 gel stent dislocation in the anterior chamber.

Figure 6 Lower-lying filtering bleb in XEN45 gel implant at 6 months.

Figure 7 (A) Hypertrophic XEN45 bleb; (B) after inferior bleb needling.

Figure 8 (A and B) AS-OCT analysis of XEN45 bleb at 6 months.

Abbreviation: AS-OCT, anterior segment-optical coherence tomography.

SheybaniALenzhoferMHohensinnMReitsamerHAhmedIIPhacoemulsification combined with a new ab interno gel stent to treat open-angle glaucoma: Pilot studyJ Cataract Refract Surg20154191905190926482822

 PubMed Web of Science ®Google Scholar

SheybaniADickBAhmedIIEarly clinical results of a novel Ab interno gel stent for the surgical treatment of open-angle glaucomaJ Glaucoma2016257e691e69626561420

 PubMed Web of Science ®Google Scholar

Pérez-TorregrosaVTOlate-PérezÁCerdà-IbáñezMCombined phacoemulsification and XEN45 surgery from a temporal approach and 2 incisionsArch Soc Esp Oftalmol2016919415421 Spanish26995503

 PubMedGoogle Scholar

De GregorioAPedrottiERussoLMorselliMMinimally invasive combined glaucoma and cataract surgery: clinical results of the smallest Ab interno gel stentInt Ophtalmol Epub2017529

 Web of Science ®Google Scholar

SchlenkerMBGulamhuseinHConrad-HengererIEfficacy, safety, and risk factors for failure of standalone Ab interno gelatin microstent implantation versus standalone trabeculectomyOphthalmology2017124111579158828601250

 PubMed Web of Science ®Google Scholar

GroverDSFlynnWJBashfordKPPerformance and safety of a new Ab interno gelatin stent in refractory glaucoma at 12 monthsAm J Ophthalmol2017183253628784554

 PubMed Web of Science ®Google Scholar

GalalABilgicAEltanamlyROsmanAXEN glaucoma implant with mitomycin C 1-year follow-up: result and complicationsJ Ophthalmol20172017545724628348884

 PubMed Web of Science ®Google Scholar

Prokosch-WillingVVossmerbaeumerUHoffmannEPfeifferNSuprachoroidal bleeding after XEN gel implantationJ Glaucoma20172612e261e26328984715

 PubMed Web of Science ®Google Scholar