Available online at www.medicinescience.org CASE REPORT Medicine Science 2019;8(3):763-5 Inferonasal XEN gel stent implantation in a refractory glaucoma patient with failed multiple glaucoma fltration surgeries: Case report Abdurrahman Alpaslan Alkan 1 , Eyup Duzgun 1 , Ali Olgun 1 , Ece Ozdemir Zeydanli 1 , Murat Karapapak 2 1 Sisli Hamidiye Etfal Education and Research Hospital, Deparment of Ophthalmology, Istanbul, Turkey 2 Polatli Duatepe State Hospital, Clinic of Ophthalmology, Istanbul, Turkey Received 13 March 2019; Accepted 22 March 2019 Available online 10.05.2019 with doi:10.5455/medscience.2019.08.9034 Copyright © 2019 by authors and Medicine Science Publishing Inc. Abstract A 59-year-old male with a history of diabetes mellitus and bilateral primary open angle glaucoma was referred to our clinic due to uncontrolled intraocular pressure (IOP) in the right eye. On examination, the visual acuity was 20/20 in both eyes and IOP was measured 22 mmHg in his right eye and 14 mmHg in his left eye despite maximal medical treatment. The patient had undergone two trabeculectomy and an EX-Press shunt surgery in the right eye previously. XEN gel stent (Allergan, Dublin, CA) implanted in the inferonasal quadrant due to the scarring in superior and nasal conjunctiva as a result of failed surgeries. The patient was followed up for 18 months with an IOP under 10 mmHg without any medication or a second intervention. XEN stent implantation may be considered as an efective option where other surgical techniques failed, and the conjunctiva is unsuitable in the superior quadrant. Keywords: Refractory glaucoma, XEN gel stent, inferonasal quadrant Medicine Science International Medical Journal 763 Introduction Trabeculectomy is the gold standard treatment for the control of intraocular pressure (IOP) in patients with open-angle glaucoma (OAG) which can not be controlled by medical treatment [1]. However, in recent years, studies have been carried out to prevent complications related to trabeculectomy and to fnd less traumatic surgical options. As a result, various minimally invasive glaucoma surgery (MIGS) techniques have started to be used in mild to moderate glaucoma patients with poor medication compliance [2]. One of these surgical techniques is the implantation of the XEN gel stent (Allergan, Dublin, CA). The XEN stent is a hydrophilic tube, which is produced by using porcine collagen-derived gelatin cross-linked with glutaraldehyde. One of the most important advantages of this technique is that it is less traumatic than other surgical techniques since it does not require a conjunctival or scleral incision [3]. With increased clinical experience and encouraging results with XEN stent, it has started to be used to after unsuccessful trabeculectomy or Ahmed Glaucoma Valve (AGV) implantation surgeries in which the superonasal conjunctiva has been preserved. [4-6]. Here, we present a case of refractory glaucoma patient who *Coresponding Author: Abdurrahman Alpaslan Alkan, Sislili Hamidiye Etfal Education and Research Hospital, Deparment of Ophthalmology, Istanbul, Turkey E-mail: alpaslan alkan@hotmail.com underwent XEN stent implantation in the inferonasal quadrant due to conjunctival scarring in the superior quadrant following multiple failed glaucoma surgeries. Case Report A 59-year-old male was referred to our glaucoma clinic for uncontrolled IOP in the right eye despite medical and surgical treatments. His past medical history was notable for type II Diabetes Mellitus. Past ocular history revealed that he had a diagnosis of primary OAG and a mini-Ex-Press Glaucoma Filtration Device (Alcon lab., Fort Worth, TX) implanted four years ago due to IOP over 30 mmHg that couldn’t be controlled with maximal medical therapy. Two years later, combined trabeculectomy with phacoemulsifcation was performed for progressive feld loss along with cataract development. Despite the surgery, adequate IOP reduction could not be achieved and a second trabeculectomy was performed six months later. After the last operation, the patient was referred to our glaucoma clinic for refractory glaucoma. On admission, the best-corrected visual acuity (BCVA) was 20/20 in both eyes. Intraocular pressure was 22mmHg in the right eye and 14mmHg in the left eye (Goldmann applanation tonometer). Biomicroscopic examination revealed iridectomies secondary to trabeculectomy surgeries at superonasal and superotemporal quadrants, fat blebs at both sides and a posterior chamber intraocular lens (IOL) in his right eye and anterior segment evaluation of the