Migration of XEN45 Implant: Findings, Mechanism, and Management

Abstract

AimThe aim of this study is to report the mechanism of XEN migration and its management.BackgroundOver the past decade, new less invasive surgical approaches for glaucoma have been devised and carried out successfully. One such technique is the use of the XEN gel stent. We present a rare and relatively unknown complication of XEN migration and present in detail the likely mechanism by which this occurs, and its subsequent management.Case descriptionA 73-year-old male with primary angle closure on maximal medical treatment presented with an intraocular pressure of 30 mm Hg in the left eye. The visual acuity was 6/5, iridocorneal angles were open in all four quadrants, and the cup disc ratio was 0.4. As phacoemulsification alone was unlikely to adequately lower intraocular pressures, the patient underwent combined phacoemulsification and XEN implantation. Although the patient had a good postoperative result with pressures lowered to 11 mm Hg, 4 months after the operation, the XEN was found to have migrated 4 mm into the anterior chamber, associated with a low-grade uveitis. The patient subsequently had the XEN explanted a new XEN inserted. Pressures lowered 1 month postoperatively to 14 mm Hg.ConclusionXEN migration is likely due to a combination of mechanical and frictional forces. If the XEN is positioned such that more than 2 mm is in the subconjunctival space, the XEN is likely to be angled upward and, therefore, be more susceptible to these forces and undergo migration.Clinical significanceIt is essential that XEN implants are correctly sited and that this is confirmed intraoperatively to prevent the need for further procedures.How to cite this articleAli ZC, Khoo DI, et al. Migration of XEN45 Implant: Findings, Mechanism, and Management. J Curr Glaucoma Pract 2019;13(2):79–81.

Aktuelle Glaukomchirurgie

“…Allerdings gibt es einen Fallbericht über eine hämorrhagische Aderhautblutung nach XEN-Gelstent-Implantation in der Literatur [ 34 ]. Außerdem ist die Migration des Stents unter der Bindehaut und auch in der Vorderkammer beschrieben [ 35 , 36 ].…”

Migration of the XEN45 Gel Stent into the Anterior Chamber Managed by Trimming the Implant

“…Complications so far reported include IOP spikes, implant exposure hypotony with maculopathy and choroidal effusions, cyclodialysis clefts, and endophthtalmitis 1. The complications of both implant migration into the anterior chamber and dislocation into the anterior chamber have been previously reported 2–4…”

“…1 The complications of both implant migration into the anterior chamber and dislocation into the anterior chamber have been previously reported. [2][3][4] Ali and colleagues described a case of a 73-year-old male with primary angle closure on maximal medical therapy who underwent combined phacoemulsification with XEN implant with a good postoperative result. At 4 months postoperatively, however, the implant was found to have migrated 4 mm into the anterior chamber, with associated uveitis.…”

“…In this case, the XEN implant was explanted and a new implant was placed in the same region. 2 Gillman and colleagues reported a case of a 64-yearold female who underwent bilateral XEN implants for normal-tension glaucoma. In the left eye, the implant migrated into the anterior chamber 2 months after needling revision.…”

“…They postulated that both mechanical and frictional forces exerted on the globe by the lid on blinking may result in migration of the implant, especially if it is not properly placed; with <2 mm in the subconjunctival space the implant may be angled upwards and more susceptible to these forces that may push the implant into the anterior chamber. In this case, the XEN implant was explanted and a new implant was placed in the same region 2…”