36-Month Outcomes of Standalone Kahook Dual Blade Goniotomy Compared with Ab-Interno Closed Conjunctiva Xen Gel Stent Implantation.

Purpose: To compare the safety and effectiveness of standalone Kahook Dual Blade (KDB) excisional goniotomy to standalone ab-interno Xen gel stent implantation in eyes with moderate-to-severe open-angle glaucoma (OAG). Methods: A single-center, retrospective study including eyes with moderate-to-severe OAG undergoing standalone KDB goniotomy or Xen gel stent implantation was conducted. Intraocular pressure (IOP), the number of antiglaucoma medications taken daily, and best-corrected visual acuity (BCVA) were recorded at baseline and for up to 36-months. Primary outcomes assessed included changes from baseline in IOP and the number of antiglaucoma medications taken. Intergroup comparisons were conducted using independent-samples Student's t-tests. The incidence of intraoperative and postoperative adverse events and the need for glaucoma surgical re-interventions were also recorded. Results: Eyes receiving standalone KDB (n=26) or Xen gel stent (n=45) surgery were analyzed. The baseline mean IOP and number of antiglaucoma medications in both groups were as follows: KDB: 23.2 ± 6.0 mmHg, 2.2 ± 1.4 medications; Xen: 22.7 ± 8.8 mmHg, 3.0 ± 1.0 medications. At 36 months, IOP was reduced to 16.6 ± 5.4 mmHg in KDB eyes (n=23, -23.5%; p=0.0004) and 15.3 ± 5.6 mmHg in Xen gel stent eyes (n=15, -22.1%; p=0.006), while number of antiglaucoma medications was reduced to 1.1 ± 0.7 (-30.8%; p=0.0005) and 2.2 ± 1.4 (-25.6%; p=0.01), respectively. Three eyes (11.5%) in the KDB group and 19 eyes (42.2%) in the Xen gel stent group required additional surgery before month 36 due to refractory high IOP. Conclusion: Both KDB goniotomy and Xen gel stent implantation significantly lowered the IOP and antiglaucoma medication burden in patients with moderate-to-severe OAG. While the Xen gel stent is frequently used to treat moderate-to-severe OAG patients with uncontrolled IOP, standalone KDB goniotomy may be equally effective as a long-term intervention, reducing the need for subsequent glaucoma surgery.

Ab-Externo XEN Gel stent implantation effectively treated refractory glaucoma with prior failed shunt tube.

PURPOSE: To assess the efficacy of a gelatin stent (XEN 45 Gel Stent; Allergan) implant in advanced glaucoma eyes that have failed prior aqueous shunt implantation. METHODS: We retrospectively reviewed 6 patients with refractory glaucoma, defined as persistently high IOP (> 21 mmHg) despite taking at least 3 IOP-lowering medications subsequent to undergoing a glaucoma drainage device (GDD) with or without a second GDD or cilioablative procedure. Eyes with previous failed GDD underwent subconjunctival 0.3 cc (0.4 mg/ml) mitomycin C, tenonectomy, and placement of an ab- externo XEN stent. The outcome measures included change in IOP and the number of glaucoma medications. Success was defined as patients achieving an IOP ≤ 18 mmHg with a percentage reduction of 25% or 15 mmHg and 40% mean IOP reduction from baseline while taking the same number or fewer medications. RESULTS: All six eyes with age of 77.6 ± 7.82 years who underwent XEN implantation following previous GDD surgery had primary open-angle glaucoma. The IOP decreased significantly from 32.33 ± 5.99 to 12.67 ± 3.27 mmHg (p < 0.001) with a follow-up of 13.9 ± 2 (11.7-16.7) months. Visual acuity and visual field remained stable after XEN placement. Compared to the baseline number of medications of 4.2 ± 0.8, all medication was discontinued except in one eye on two drops at the end of the follow-up. The overall surgical success rate was 100%. No complications, needling, or additional procedures were required. CONCLUSION: This study described successful implantation of the XEN stent following failed GDD. XEN Gel stent implantation associated with mitomycin C and tenonectomy can be considered a viable surgical option for patients with a history of previously failed tube shunt requiring further IOP lowering.

XEN45 gel stent in the treatment of pigmentary glaucoma: A two-year follow-up.

PURPOSE: To investigate safety and efficacy of the XEN gel stent in patients with pigmentary glaucoma (PG). METHODS: A retrospective analysis of 26 eyes of 19 patients with PG undergoing XEN gel stent implantation was performed. Best-corrected visual acuity, intraocular pressure (IOP), and number of antiglaucoma medications were analyzed preoperatively, and at 2 weeks and 3, 6, 12, and 24 months after surgery. Success, needling, and complications were analyzed. Complete success was defined as an IOP reduction of >20% and achieving a target IOP of ≤18, ≤15, or ≤12 mmHg without antiglaucoma medication. Qualified success was indicated if the IOP target was reached with or without medication. RESULTS: Mean IOP decreased significantly from 27.6 ± 14.3 (standard deviation, SD) mmHg to 14.3 ± 4.6 mmHg after one year (p < 0.001) and 15.1 ± 2.7 mmHg (p < 0.001) after two years. The median number of hypotensive drugs declined significantly from 4 (range: 3-5) to 0 (0-2) and 0 (0-3) after one and two years, respectively. After two years, complete success with an IOP of ≤18 mmHg and ≤15 mmHg was achieved in 73.1% and 61.5%, respectively. Half of the eyes required needling after a median time of 8 months (0.5-34 months). No sight-threatening complications were observed. CONCLUSION: The XEN gel stent is a safe and effective surgical treatment option for PG. Needling is an important part of the procedure and should be communicated preoperatively to the patients.

Complications of XEN gel stent implantation for the treatment of glaucoma: a systematic review.

Aim: This study was aimed to summarize the complications and their management associated with XEN gel stent implantation. Methods: A systematic review of literature was conducted using Medline (via PubMed), EMBASE, the Cochrane Library databases, and China National Knowledge Infrastructure, from their inception to February 1, 2024. Results: A total of 48 studies published between 2017 and 2024 were identified and included in the systematic review, including 16 original studies (retrospective or prospective clinical studies), 28 case reports, and 4 case series, which followed patients for up to 5 years. Early postoperative complications of XEN gel stent implantation include hypotony maculopathy (1.9-4.6%), occlusion (3.9-8.8%), suprachoroidal hemorrhage (SCH), choroidal detachment (0-15%), conjunctival erosion, and exposure of the XEN gel stent (1.1-2.3%), wound and bleb leaks (2.1%) and malignant glaucoma (MG) (2.2%). Mid-postoperative complications of XEN gel stent implantation included migration of XEN (1.5%), ptosis (1.2%), endophthalmitis (0.4-3%), macular edema (1.5-4.3%), hypertrophic bleb (8.8%) and subconjunctival XEN gel stent fragmentation (reported in 2 cases). Late postoperative complications reported in cases included spontaneous dislocation and intraocular degradation. Conclusion: XEN gel stent implantation is a minimally invasive glaucoma surgery (MIGS) procedure for glaucoma, known for its potential to minimize tissue damage and reduce surgical duration. However, it is crucial to note that despite these advantages, there remains a risk of severe complications, including endophthalmitis, SCH, and MG. Therefore, postoperative follow-up and early recognition of severe complications are essential for surgical management.

Comparing Outcomes of 45 µm Gelatin Stent Placed ab Externo with Open Conjunctiva to ab Externo with Closed Conjunctiva.

PURPOSE: Compare outcomes of a gelatin stent (XEN45 Gel Stent [XGS]) placed either ab externo with open conjunctiva (AEO) or ab externo with closed conjunctiva (AEC) with or without cataract surgery in patients with glaucoma. DESIGN: Retrospective nonrandomized comparative study. PARTICIPANTS: A total of 86 eyes from 86 glaucoma patients who received XGS placed either AEO (N = 49) or AEC (N = 37) with or without cataract surgery between May 2019 and April 2022 at Massachusetts Eye and Ear. METHODS: Reviewed and analyzed 809 visits from patient charts from a level 3 triage center. MAIN OUTCOME MEASURES: Intraocular pressure (IOP), medication burden, Kaplan-Meier (KM) success rates, 5-fluorouracil (5-FU) impact, and complications. RESULTS: Baseline demographics were similar between both groups, except for baseline IOP and glaucoma type. Both AEO and AEC procedures resulted in significant patterns of IOP and medication reduction from baseline up to 1 year. The AEO procedure had significantly higher KM qualified success (QS) rates than the AEC procedure, but similar complete success (CS) rates. Under QS, the cumulative probability of survival was 73% in the AEO group and 51% in the AEC group at month 6 and 62% in the AEO group and 20% in the AEC group at year 1. Under CS, the cumulative probability of survival was 41% in the AEO group and 37% in the AEC group at month 6 and 29% in the AEO group and 14% in the AEC group at year 1. The AEO procedure had significantly more IOP reduction than the AEC procedure at all postoperative time points beyond week 2, but similar medication burden reduction. At postoperative year 1 (POY1), the mean IOP was reduced to 10.72 ± 5.71 mmHg on 1.16 ± 1.68 medications after AEO and 17.03 ± 2.37 mmHg on 1.59 ± 1.21 medications after AEC. Phacoemulsification (phaco) was not a significant factor while 5-FU usage trended toward significance. Procedure time was longer for standalone XGS AEO. CONCLUSIONS: We demonstrate that both placements reduce medication and IOP from baseline, with AEO placement having more favorable XGS success rates and IOP control at the expense of longer procedure time and greater 5-FU usage. FINANCIAL DISCLOSURE(S): Proprietary or commercial disclosure may be found in the Footnotes and Disclosures at the end of this article.

Five-year outcomes of ab interno Xen 45 gel stent implantation.

BACKGROUND: To assess the safety and 5-year efficacy of ab interno XEN 45 gel stent implantation with phacoemulsification in primary open-angle glaucoma (POAG). METHODS: Single-centre, single-surgeon, retrospective case note review of consecutive OAG patients who underwent ab-interno gel stent placement combined with phacoemulsification. Surgeries were performed between 2/01/2014 and 2/01/2016. PRIMARY OUTCOME MEASURES: mean reduction in intraocular pressure (IOP) and change in number of ocular hypotensive medications from baseline (follow-up range 1-7 years; mean 54 months). SECONDARY OUTCOME MEASURE: change in visual field mean deviation (VFMD) from baseline. Safety data included intraoperative and post-operative complications and adverse events. Failure was defined by IOP reduction < 20% despite maximum medical therapy, the need for further laser or surgical intervention. At 5 years, 75% of eyes were free from failure (95% CI 64 to 83%). RESULTS: Ninety-one eyes were analysed. Mean (SD) IOP and medications decreased from 20.2 (6.4) mmHg and 2.9 (1.0) at baseline to 15.4 (3.6) mmHg (p < 0.001) and 1.5 (1.4) medications at 5 (p < 0.001) years. Baseline mean VFMD (SD) was - 10.3dB (8.5) reducing to - 10.9(8.2) (p < 0.01) at 5 years. Two (2%) eyes had intraoperative complications, 4 (4.3%) experienced post-operative AEs, and 13 (14%) required secondary surgical intervention (SSI). CONCLUSION: The gel stent combined with phacoemulsification was effective in reducing IOP and medications over 5 years, with an acceptable safety profile. Visual field change was clinically acceptable through the study period.

Comparing Outcomes of Trabeculotomy with Mitomycin C to 45-µm Gelatin Stent Placed Ab Externo with Open Conjunctiva.

PURPOSE: To compare trabeculectomy with mitomycin C (trab-MMC) and XEN45 Gel Stent placed ab externo with open conjunctiva (XGS AEO) with or without cataract surgery in patients with glaucoma. DESIGN: Nonrandomized, retrospective, comparative study. SUBJECTS: A total of 204 eyes from 204 glaucoma patients who received XGS AEO or underwent trab-MMC with or without cataract surgery between July 2018 and August 2021 at Massachusetts Eye and Ear. METHODS: Visits from 204 patient charts were reviewed after either trab-MMC or XGS AEO from 2018 to 2021 from a level 3 triage center. MAIN OUTCOME MEASURES: Intraocular pressure (IOP), medication burden, Kaplan-Meier success rates, 5-fluorouracil impact, and complications. RESULTS: One hundred fifty-seven patients underwent trab-MMC and 47 underwent XGS AEO. Groups had similar baseline intraocular pressure (IOP) and medications (meds). Intraocular pressure and meds decreased similarly at 1.5 years (11.2 mmHg vs. 7.4 mmHg, P = 0.62; 2.9 vs. 2.8 meds, P = 0.92, respectively for trab-MMC and XGS AEO). Success was defined as IOP reduction ≥ 20% with 5 mmHg ≤ IOP ≤ 18 mmHg for 2 consecutive visits. Complete success (CS) did not allow meds; qualified success (QS) allowed for ≤ baseline meds. When IOP fluctuations in the first 60 days were not counted as failures, CS was 43% for trab-MMC, about 8.5% higher than for XGS AEO (P < 0.01). Qualified success was similar between the groups (65%-67%). Procedure time was shorter for XGS AEO than trab-MMC (44 vs. 63 minutes, P < 0.01). CONCLUSIONS: XEN45 Gel Stent AEO may provide similar benefits to trab-MMC, especially for patients who tolerate some meds, with shorter procedure times. FINANCIAL DISCLOSURE(S): Proprietary or commercial disclosure may be found in the Footnotes and Disclosures at the end of this article.

Bleb Morphology on Anterior-Segment Optical Coherence Tomography after XEN Gel Stent Implantation.

We investigated the internal morphology of filtration blebs after XEN gel stent implantation using anterior segment optical coherence tomography (AS-OCT) and identified factors related to intraocular pressure (IOP) postoperatively. Eighteen eyes of 18 patients who had undergone XEN gel stent implantation were analyzed. Blebs were imaged using Visante OCT (Carl Zeiss Meditec AG, Germany) at 6 months and 1 year after surgery and evaluated for quantitative parameters including bleb height, maximum height of internal cavity, maximum bleb wall thickness, and maximum bleb epithelial thickness. Subjects were classified into two groups according to the presence or absence of a definite internal cavity between the conjunctiva and sclera using AS-OCT imaging. Nine eyes (50%) were assigned to the internal cavity group and 9 (50%) to the uniform group. Postoperative IOP was significantly lower in the internal cavity group than in the uniform group both at 6 months and 1 year after surgery (p = 0.024 and p = 0.040). Postoperative IOP showed statistically significant negative correlations with bleb height and the height of the internal cavity (Spearman correlation coefficient r = -0.518, p = 0.028 and r = -0.453, p = 0.034, respectively). AS-OCT facilitates analysis of bleb morphology after XEN gel stent implantation. A larger height of the internal cavity of the bleb appeared to correlate with lower IOP after XEN implantation.

A case of mitomycin C toxicity after XEN gel stent implantation with the XEN air technique in a glaucoma patient.

BACKGROUND: To discuss the first case of mitomycin C (MMC) toxicity after XEN® gel stent implantation in a glaucoma patient, conducted using the XEN "air" technique with an ophthalmic viscosurgical device (OVD). CASE PRESENTATION: A 44-year-old Asian male presented with increased intraocular pressure (IOP; 52 mmHg) accompanied by keratic precipitates and an edematous cornea. He was diagnosed with uveitic glaucoma in the left eye, and the IOP was controlled with a topical anti-glaucoma agent. However, glaucoma progression was revealed by Humphrey visual field (HVF) and optical coherence tomography (OCT) examinations. The patient underwent uneventful XEN gel stent implantation using the XEN air technique and an MMC (0.02%, 0.1 mL) injection, with subconjunctival air and OVD injection provided prior to XEN implantation in the left eye. The patient exhibited a decreased IOP (11 mmHg), elevated bleb, and extensive subconjunctival hemorrhage on postoperative day 1. On postoperative day 18, diffuse conjunctival injection and a large avascular bleb was noticed around the XEN gel stent. The patient complained of severe eye pain and discomfort, suggestive of MMC toxicity, and the IOP was 12 mmHg. The patient was treated with a topical steroid and antibiotics tapered over a 6-month period. Finally, the toxicity was successfully controlled, with the IOP stabilizing at around 15 mmHg. CONCLUSIONS: Although significantly greater lowering of the IOP can be expected with the use of subconjunctival OVD injection and MMC during XEN gel stent implantation, a cautious approach and a longer monitoring period are required.

Recanalization of Xen45 gel stent implant occlusion using 10 - 0 nylon suture in refractory glaucoma: a case report.

BACKGROUND: Xen Gel Stent implant is a new minimally invasive surgical treatment for glaucoma that has been proven effectiveness and safety profile. However, it may also lead to some complications. Xen Gel Stent occlusion is a relatively rare complication reported less frequently and has limited treatment experience. In our case report, we proposed a novel surgical treatment using a 10 - 0 nylon suture to successfully recanalize the occluded Xen45 Gel Stent. CASE PRESENTATION: A 16-year-old female patient had bilateral juvenile glaucoma for the past 5 years. Her right eye had undergone three glaucoma surgeries but failed. At a presentation to our hospital, the right eye's intraocular pressure (IOP) was 30 mmHg despite applying four different active principles. Xen45 Gel Stent implant was chosen for treatment, but six days after implantation, the IOP rose to 40 mmHg as a result of an anterior chamber tip occlusion of the Xen45 Gel Stent. Nd: YAG laser shockwave therapy was attempted but failed. The patient eventually had to return to the operating room for a revision procedure. The Xen45 Gel Stent was recanalized from the ab externo by making an L-shaped conjunctival incision at the fornix base and threading a 10 - 0 nylon suture through it. The IOP was successfully controlled in the 11-month follow-up without medication. CONCLUSION: If postoperative occlusion arises after Xen45 Gel Stent implantation, surgery using 10 - 0 nylon suture to recanalize Xen45 Gel Stent should be considered as a relatively safe, effective that does not require removal of Xen45 Gel Stent.

XEN Gel Stent for Conjunctiva with Minimal Mobility Caused by Scleral Encircling: A Case Report.

This case report describes the successful use of a XEN gel stent for controlling intraocular pressure (IOP) in a patient who had previously undergone scleral encircling for rhegmatogenous retinal detachment. The patient had very limited mobile conjunctiva due to scarring caused by the earlier surgery, which limited their options for glaucoma surgery. The XEN gel stent, a minimally invasive glaucoma surgery (MIGS) procedure that does not require opening the conjunctiva, was implanted in the subconjunctival space using an ab interno approach. Postoperative blebs were imaged using anterior segment optical coherence tomography, and IOP was monitored over six months. This study found that the XEN gel stent effectively controlled the IOP, and there were no complications during or after surgery. This case report may expand the indication for the XEN gel stent, which could be considered a viable option for patients who have undergone scleral buckling and have limited mobile conjunctiva.

A Comparative Analysis of Morphology and Dimensions of Functional Blebs following PRESERFLO-Microshunt and XEN-Gel-Stent, a Study Using Anterior Segment OCT.

Evaluation of bleb morphology is a vital part of successful filtration glaucoma surgery. The PRESERFLO-MicroShunt (PRESERFLO) and XEN-Gel-Stent (XEN) are drainage devices implanted using different surgical approaches (ab externo and ab interno, respectively), potentially resulting in distinct bleb morphology. Understanding these morphological differences is essential for postoperative care. In this study, we retrospectively examined functioning blebs following PRESERFLO and XEN implantation using high-resolution anterior segment OCT imaging. Qualitative assessment utilizing the Jenaer Bleb Grading System and quantitative assessment measuring 12 parameters representing bleb dimensions were conducted, and the results were compared between the two groups. A total of 80 eyes from 80 patients were included (41 after PRESERFLO, 39 after XEN). Functioning blebs following PRESERFLO exhibited a higher frequency of hyperreflective tenon changes compared to XEN (31.7% vs. 10.3%, respectively, p = 0.02) and a lower frequency of cavernous changes (17.1% vs. 35.9%, p = 0.05). Additionally, PRESERFLO blebs showed a higher frequency of visible episcleral lakes (92.7% vs. 30.8%, p < 0.001). Furthermore, PRESERFLO blebs demonstrated larger height (2.13 ± 0.5 vs. 1.85 ± 0.6 mm, p = 0.03), width (10.31 ± 2.3 vs. 9.1 ± 2.3 mm, p = 0.02), length (9.13 ± 1.8 vs. 8.24 ± 1.9 mm, p = 0.04), posterior location relative to the limbus (6.21 ± 1.2 vs. 5.21 ± 1.8 mm, p = 0.005), and a thicker bleb wall (1.60 ± 0.5 vs. 1.1 ± 0.4 mm, p = 0.004). Functioning blebs following PRESERFLO and XEN displayed morphological distinctions, likely attributed to variations in surgical techniques (ab externo vs. ab interno) and stent dimensions. These morphological differences should be taken into consideration when evaluating blebs, as they could impact assessments of bleb functionality and influence decisions regarding postoperative interventions.

Utilidad del injerto de membrana amniótica en el manejo de la exposición del implante XEN® / Usefulness of the amniotic membrane graft in the management of the exposure of the XEN® implant

Se presenta el caso de una mujer de 79 años con glaucoma severo y falta de adherencia al tratamiento, que es sometida a cirugía de catarata e implante XEN® en su ojo izquierdo. Dos semanas después de la intervención se objetiva una erosión conjuntival con exposición del extremo distal del implante, por lo que se realiza una reparación quirúrgica mediante la combinación de una sutura aposicional del tubo, adaptando su trayectoria a la curvatura escleral, y el recubrimiento con injerto de membrana amniótica. Tras 6 meses de seguimiento, presenta una presión intraocular controlada, sin necesidad de tratamiento adicional, y sin mostrar progresión de su enfermedad (AU)

We report a case of a 79-year-old woman with severe glaucoma and absence of therapeutic adherence, who underwent cataract surgery and XEN® implant in her left eye. Two weeks after the intervention, conjunctival erosion was observed with exposure of the distal end of the implant, so a surgical repair was performed by combining an appositional suture of the tube, adapting its trajectory to the scleral curvature, and an amniotic membrane graft. After 6 months of follow-up, the intraocular pressure was controlled, without additional treatment needed, and no disease progression (AU)

Usefulness of the amniotic membrane graft in the management of xen® implant exposure.

We report a case of a 79-year-old woman with severe glaucoma and absence of therapeutic adherence, who undergone cataract surgery and XEN® implant in her left eye. Two weeks after the intervention, conjunctival erosion was observed with exposure of the distal end of the implant, so a surgical repair was performed by combining an appositional suture of the tube, adapting its trajectory to the scleral curvature, and an amniotic membrane graft. After 6 months of follow-up, the intraocular pressure is controlled, without additional treatment needed, and no disease progression.

Theoretic scientific rationale of double XEN 45 Gel Stent implant in severe glaucomatous ocular hypertension.

PURPOSE: To investigate the theoretical hydrodynamic effects of a single or a double XEN 45 Gel Stent (XEN45) implant in glaucomatous eyes. METHODS: A prospective non-randomized clinical study on 63 glaucomatous eyes of 63 patients. The preoperative intraocular pressure (IOP) values after 14 days of medical therapy washout was correlated to the postoperative IOP values 7 and 45 days after the implant of a XEN45. A mathematical model based on the Hagen-Poiseuille law was designed to assess the residual aqueous humor outflow (AHO) facility in glaucomatous eyes in function of the postoperative IOP reduction. Using XEN45 as unit of measurement, we transformed through equations the residual preoperative AHO in XEN45 equivalent in order to establish theoretical number of stents needed to reach the target IOP. RESULTS: The mean preoperative washout IOP was 28.9 ± 5.4 mmHg, after 7 and 45 days the mean postoperative IOP was 12.6 ± 4.3 and 15.3 ± 4.4 mmHg, respectively (p < 0.001). A significant positive correlation was found between preoperative and postoperative IOP values. We obtained a mathematical relationship to estimate the theoretical number of XEN45 stents needed to reach the target IOP. CONCLUSION: The basal IOP (after medical therapy washout) is a predictive factor for the surgical success after a XEN45 implant. Establishing the residual preoperative AHO it is possible to predict the theoretical number of stents to implant. A double XEN45 implant could be considered a possible further tool to reach the target IOP in patients with severe AHO deficiency.

Risk factors for ocular hypotony after XEN Gel Stent implantation.

PURPOSE: To investigate the incidence of postoperative hypotony, and risk factors for the development of hypotony in eyes who had undergone XEN Gel Stent implantation. METHODS: In this retrospective, single-centre case series, medical records of 170 consecutive eyes who had undergone XEN Gel Stent implantation with or without simultaneous phacoemulsification for primary or secondary open angle glaucoma were analysed. Primary outcome parameters were the incidence of postoperative hypotony and potential risk factors for its development, and secondary parameters were pre- and postoperative visual acuity, intraocular pressure (IOP), and number of IOP-lowering eye drops. RESULTS: Postoperative hypotony ≤ 6 mmHg occurred in 57% of eyes. Hypotony was without complications in 70.1%, 13.4% had transient complications with spontaneous resolution, and 16.5% had complications requiring treatment. Mean visual acuity logMAR before surgery accounted for 0.47 ± 0.46 in all eyes and 0.47 ± 0.48 at the 4-week visit. There was no significant difference of BCVA in the group of eyes with and without postoperative hypotony before and after surgery. The mean IOP before surgery was 24.6 ± 8.4 mmHg and decreased significantly to 18.4 ± 10.2 after 4 weeks. Eyes with an axial length over 24.3 mm had a threefold increased risk for postoperative hypotony (OR 3.226, 95% confidence interval 1.121-9.279). This risk was decreased in eyes with simultaneous cataract surgery (OR 0.483, 95% confidence interval 0.258-0.903). CONCLUSION: In our sample, postoperative hypotony was a common complication after XEN Gel Stent implantation, but serious, persistent complications were rare. A longer axial length predisposes the eye for the development of hypotony.

[Bleb morphology using optical coherence tomography : After primary implantation of XEN gel stent and open conjunctival revision]. / Morphologie des Sickerkissens mittels optischer Kohärenztomographie : Nach primärer Implantation von XEN-Gel-Stent und offener Bindehautrevision.

BACKGROUND: The implantation of a XEN gel stent is an innovative method for filtration surgery using an ab interno approach. The morphological evaluation of the resulting bleb is decisive for surgical success. Bleb revision is frequently needed after XEN implantation and might affect the bleb morphology. Aim of this study was to examine bleb morphology using anterior segment OCT (AS-OCT) and analyze the morphological differences of blebs after primary XEN implantation and after bleb revision. MATERIAL AND METHODS: Included were eyes that underwent XEN implantation (Pr-X) or bleb revision after XEN (Re­X group). An AS-OCT of blebs was performed and images were classified using a novel classification system (the Jenaer bleb grading system, JBGS). Frequency of different tomographic patterns (M) and their correlation with intraocular pressure (IOP) were analyzed. RESULTS AND DISCUSSION: A total of 69 eyes (40 in the Pr­X and 29 in the Re­X groups) were included. At the conjunctival level, the most common M in both groups was subconjunctival spaces (M-C2) followed by intraconjunctival cysts (C1) and no conjunctival changes (C0). No differences of frequencies between the two groups or of IOP between the three Ms were seen. At the tenon level, the most commonly seen Ms in the Pr­X group were hyporeflective and cavernous changes (M-T2, T3) followed by no changes (M0) and hyperflective changes (T1). In the Re­X group, the M­T1 and T2 were most commonly seen followed by T3 and T0. The M­T2 and T3 in the Pr­X group and the M­T1 and T2 in the Re­X group correlated with lower IOP. An episcleral lake (M-ES1) was seen significantly less frequently in the Pr­X group compared with Re­X group where it correlated with lower IOP CONCLUSION: The hyperreflective changes at the tenon level and the presence of an episcleral lake were seen more frequently following bleb revision compared with primary XEN implantation and correlated with lower IOP. The interpretation of bleb morphology using AS-OCT should only be done considering the surgical approach used.

Bleb Associated Xen Gel Stent Endophthalmitis: A Case Report and Review of Literature.

PURPOSE: To report a case of a unique late complication of the Xen gel stent, stent-related endophthalmitis was preceded by flattening of the bleb. CASE REPORT: A 63-year-old female was presented with late-onset endophthalmitis preceded by flattening of the bleb two years post-insertion of Xen gel stent. B-scan of the posterior chamber revealed vitritis and hyaloid condensation, with no viral, fungal, or bacterial pathologies identified on anterior chamber tap. The patient's eye responded to injections of intravitreal antibiotics. CONCLUSION: Endophthalmitis can occur as late as 2 years after implantation of glaucoma drainage device implants (GDIs) like the Xen gel stent if bleb flattening or leaking leads to contact of the stent with the conjunctiva. Therefore, in case of blebs getting flat, ophthalmologists should watch them more often. Intravitreal antibiotics may also be effective rather than surgical removal in the case of a non-eroded stent complicated by endophthalmitis.

Management of XEN Gel Stent Exposure with Conjunctival Erosion via Rotational Conjunctival Flap and Amniotic Membrane Transplantation-A Case Report.

Background: Despite its proven effectiveness and safety profile, the XEN gel stent (Allergan Inc., CA, USA) for minimally invasive glaucoma surgery (MIGS) has a probability of postoperative complications, including postoperative hypotony, hyphema, stent migration, stent obstruction, bleb fibrosis, and fibrin formation. In particular, the use of adjunctive Mitomycin-C (MMC) might be associated with bleb-related complications, including conjunctival erosion, XEN gel stent exposure, and blebitis. However, there are few studies on XEN gel stent exposure and its management. We describe a case of XEN gel stent exposure with conjunctival erosion 18 months postoperatively, which resolved effectively after combination treatment with a rotational conjunctival flap and amniotic membrane transplantation. Case presentation: A 74-year-old Korean male patient with diabetes and hypertension underwent uncomplicated ab interno XEN gel stent implantation with a subconjunctival injection of 0.1 cc of 0.02% MMC and presented with low intraocular pressure (IOP) with a well-functioning filtering bleb. Periocular pain and tearing developed 18 months after the initial operation, with mild deterioration of visual acuity to 20/100. Despite conservative medical treatment, the conjunctival erosion was not relieved. Anterior segment optical coherence tomography (AS-OCT) revealed an exposed XEN gel stent with conjunctival erosion. We performed bleb revision surgery using a rotational conjunctival flap and amniotic membrane transplantation. Slit-lamp examination and AS-OCT showed a well-formed moderate bleb without leakage, and IOP continued to be well controlled (14 mm Hg with latanoprost) until six months after bleb revision. Conclusions: This case report highlights the importance of careful examination, including slit-lamp examination, the Seidel test, and AS-OCT, to identify accurate anatomical positioning and to monitor ocular surface changes after XEN gel stent implantation with MMC or 5-FU. Combination treatment (rotational conjunctival flap and amniotic membrane transplantation) may be relatively safe for persistent XEN gel stent exposure.

Outcomes of Deep Sclerectomy following Failed XEN Gel Stent Implantation in Open-Angle Glaucoma: A Prospective Study.

Background: The purpose of this study is to evaluate the outcome of deep sclerectomy (DS) as a secondary procedure following failed ab-interno XEN gel stent implantation in patients with open-angle glaucoma. Methods: Prospective, single-center, non-randomized, interventional study. Consecutive eyes that underwent mitomycin C (MMC) augmented XEN gel stent surgery, with uncontrolled intraocular pressure (IOP) or signs of disease progression, were included to undergo MMC-augmented DS. Primary efficacy outcome was surgical success, defined as complete when the unmedicated IOP was 12 mmHg or less, or 15 mmHg or less and 20% lower than at the timing of XEN failure and defined as qualified when the IOP fulfilled the same conditions with fewer medications than before deep sclerectomy. Secondary measures were mean reduction in IOP and in the number of medications, and the rates of complications. Results: Seventeen eyes were enrolled with a mean age of 72.1 ± 8.2 years (66.7% women). The mean follow-up was 20.1 ± 4.9 months, with more than 12-month data available from 15 eyes. Following DS, IOP decreased significantly from 22.6 ± 5.3 mmHg to 12.3 ± 5.5 (45.6%; p < 0.001). Antiglaucoma medications dropped from 1.1 ± 0.9 to 0.3 ± 0.7. Complete success was obtained in 40% of eyes using the threshold of 12 mmHg or less and a 20% decrease of IOP, and in 60% using the 15 mmHg or less threshold. Adverse events were observed in 20% of eyes (bleb leakage (13.3%); hypotony (6.7%)). No cases of choroidal detachment or hypotony maculopathy were reported. Conclusions: Failed XEN gel stent implantation does not seem to negatively affect the safety and efficacy of subsequent deep sclerectomy surgery.