XEN Gel Stent Implantation Research Articles

Three-year results of XEN gel stent implantation in the treatment of glaucoma

Objective: To evaluate the long-term efficacy and safety of XEN gel stent implantation in patients with refractory glaucoma. Methods: A retrospective case series study was conducted. Clinical data were collected from patients who received medical treatment at the First Affiliated Hospital of Fujian Medical University between January 2020 and September 2020 and underwent XEN gel stent implantation by the same surgeon. Preoperative and postoperative clinical parameters, including the intraocular pressure (IOP), number of ocular hypotensive medications, best-corrected visual acuity, surgical success rates, status of filtering blebs, and complications, were recorded at 1 day, 1 week, 1, 2, 3, 6, 12, 18, 24, and 36 months after surgery. Statistical analyses were performed using the analysis of variance (ANOVA), the least significant difference (LSD) method, and the Fisher's precision probability test. Results: A total of 8 patients (8 eyes) with glaucoma meeting the criteria were included, consisting of 6 males (6 eyes) and 2 females (2 eyes). The preoperative IOP reached (30.88±12.17) mmHg (1 mmHg=0.133 kPa), and the IOP at all postoperative follow-up time points was significantly lower than the preoperative value (P<0.05). At 3 years after surgery, the IOP was (14.38±1.60) mmHg, with a reduction of 53.43% [(16.50±12.07) mmHg]. Only 2 patients required monotherapy for IOP control, and there was no significant decline in best-corrected visual acuity in 7 patients. The surgical outcome at 3 years postoperatively was a complete success in 6 patients, a qualified success in 1 patient, and a failure in 1 patient. The filtering blebs were generally flat and diffuse, with only mild to moderate vascularization. One patient presented elevated IOP at 3 months, and after a subsequent revision of the XEN gel stent, the IOP became stable with the administration of travoprost eye drops. Conclusion: The XEN gel stent implantation proved to effectively reduce the IOP in glaucoma patients, with a high degree of safety demonstrated up to 3-year long-term follow-up.

Clinical effect of XEN gel stent implantation or combined with phacoemusification and intraocular lens implantation on glaucoma

Objective: To evaluate the efficacy and safety of internal XEN gel stent implantation or combined with phacoemusification and intraocular lens (IOL) implantation in the treatment of glaucoma. Methods: It was a retrospective case series study. Forty-five patients (28 males and 17 females; 52 eyes) who had different types of glaucoma treated at the Shenzhen Eye Hospital from December 2021 to June 2023 were included. XEN gel stent implantation (the XEN group) or XEN implantation combined with phacoemusification and IOL implantation (the combined group) were performed in these patients. The postoperative follow-up was 18 months. The observational indexes included the best corrected visual acuity (recorded as the logarithm of the minimum angle of resolution), intraocular pressure (IOP), XEN implantation quadrant, number of IOP-lowering medications, corneal endothelial cell count, operation success rate and surgical complications. The one-way repeated measures of variance, LSD-t test, and rank sum test were used for statistical analysis. Results: There were 28 patients (33 eyes) in the XEN group and 17 patients (19 eyes) in the combined group. The postoperative best corrected visual acuity had no significant change in the XEN group, but improved significantly (0.21±0.30 at 6 months; P<0.05) in the combined group, compared with the preoperative value. The IOP of the two groups at 18 months after surgery [(12.2±3.1) and (11.9±3.9) mmHg (1 mmHg=0.133 kPa)] was significantly lower than that before surgery [(22.1±8.5) and (19.4±10.2) mmHg; P<0.05]. The average number of IOP-lowering medications in all patients was 3 (2, 3) before surgery and 0 (0, 0) at 18 months after surgery. The difference was statistically significant (P<0.05). In the XEN group, the corneal endothelial cell count was (2 387.37±478.22) cells/mm² preoperatively and (2 193.89±311.96) cells/mm² at 12 months. The decrease showed no statistical significance. The XEN gel stent was implanted in the supranasal quadrant in 8 eyes (15.4%), in the inferonasal quadrant in 36 eyes (69.2%), and in the infratemporal quadrant in 8 eyes (15.4%). The operation success rate [complete success rate, 86.5% (45/52); conditional success rate, 9.6% (5/52)] was 96.2% (50/52). The filtering bleb scarring occurred in 9.6% (5/52) of eyes. A small amount of hyphema, postoperative shallow anterior chamber, transient hypertension, and intraoperative drain breakage were found in 7.7% (4/52) of eyes, respectively. A small amount of subconjunctival bleeding was observed in 5.8%(3/52) of eyes. Re-implantation of an XEN gel stent was performed in 5.8% (3/52) of eyes. The intraoperative conjunctival tissue rupture, hypotony macular edema, and drain exposure were observed in 1.9% (1/52) of eyes, respectively. Conclusion: The XEN gel stent implantation or combined with phacoemusification and IOL implantation was effective and safe in treating different types of glaucoma, but its long-term clinical efficacy needs further follow-up observations in multi-center, larger-scale research.

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

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). 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'st-tests. The incidence of intraoperative and postoperative adverse events and the need for glaucoma surgical re-interventions were also recorded. 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. 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

PurposeTo assess the efficacy of a gelatin stent (XEN 45 Gel Stent; Allergan) implant in advanced glaucoma eyes that have failed prior aqueous shunt implantation.MethodsWe 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.ResultsAll 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.ConclusionThis 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.

Complications Following XEN45 Gel Stent and Glaucoma Drainage Device Implantation During Glaucoma Fellowship.

Purpose XEN45 Gel Stent and glaucoma drainage device (GDD) implantation is safe and effective for glaucoma treatment and should be taught during glaucoma fellowship training. However, complications may still occur, with potentially sight-threatening consequences. The purpose of this study is to describe the management of complications following a series of XEN45 Gel Stent and GDDsurgeries performed over the course of glaucoma fellowship training. Methods This is a retrospective case series of XEN45 Gel Stent surgeries performed on 16 eyes and GDD surgeries performed on seven eyes. Patient demographics, disease characteristics, and complications are reviewed. The intra- and postoperative course of five select cases with complications are described in detail. Results The most frequent complications following XEN45 implantation were transient hypotony (10 eyes, 63%), reduced visual acuity (VA) (five eyes, 31%), choroidal effusion (three eyes, 19%), hyphema (two eyes, 13%), and intraocular pressure (IOP) spike (two eyes, 13%). Thirteen eyes (81%) required bleb needling, and three eyes (19%) required XEN45 replacement. Complications following GDD implantation included hypotony (three eyes, 43%), reduced VA (two eyes, 29%), choroidal effusion (two eyes, 29%), IOP spike (two eyes, 29%), implant exposure (two eyes, 29%), and shallow anterior chamber (one eye, 14%). Three eyes (43%) required revision or explantation with a secondary glaucoma surgery. One choroidal effusion following XEN45 surgery and one following GDD surgery were hemorrhagic choroidal effusions requiring surgical drainage. Conclusion Significant and potentially sight-threatening complications may occur following XEN45 Gel Stent and GDD implantation performed over the course of fellowship training. Glaucoma fellows should be ably equipped to recognize, diagnose, and manage these complications both intra- and postoperatively.

Two-Year Results of XEN Gel Stent Implantation for Pseudoexfoliative Glaucoma in Phakic versus Pseudophakic Eyes.

Objectives: To investigate whether phakia affects the outcome of XEN-45 gel stent implantation in the treatment of pseudoexfoliative glaucoma (PXG). Methods: A retrospective, comparative cohort study of 30 phakic and 55 pseudophakic PXG patients who received the XEN-45 gel stent at a tertiary centre. The primary outcome measure was two-year success defined as a ≥20% lowering of intraocular pressure (IOP) and a target IOP of 6-21 mmHg. Success was complete without and qualified irrespective of antiglaucoma medication use. Further glaucoma surgery other than needling was regarded as a failure. The secondary outcome measures included changes in IOP, revision and complication rates. Results: The complete two-year success rates were 70% and 59% in the phakic and pseudophakic groups, respectively (p = 0.75, log-rank test), and the qualified rates were 80% and 72%, respectively (p = 0.89). The median IOP reduction from baseline was 54% in phakic, and 46% in pseudophakic eyes. While needling rates were similar, the incidence of early incisional bleb revisions was significantly higher in the phakic eyes (13% vs. 0% within 3 months; p = 0.0098, chi-square). Increasing after a year, significantly more pseudophakic eyes failed due to secondary glaucoma surgery (16% vs. 0%; p = 0.0191). Conclusions: The XEN-45 gel stent offers equally effective IOP control for both phakic and pseudophakic patients. However, the onset of bleb revisions and the necessity for secondary glaucoma surgery differed significantly between the groups.

Concurrent ciliary body detachment in patients presenting with serous choroidal detachment following glaucoma surgery

PurposeTo examine the rate of ciliary body detachment in patients with choroidal detachment following glaucoma surgery and its effect on the clinical course, management, and prognosis.MethodsA prospective observational case-series study. Patients with choroidal detachment following glaucoma surgery in 2018–2019 were included. All underwent complete ophthalmological examination and ultrasound biomicroscopy for evaluation of the presence and extent of ciliary body detachment. Follow-up examinations including ultrasound biomicroscopy scans were performed at 1 week, 1 month, 3 months, and 6 months.ResultsEight patients (8 eyes) were enrolled, 4 male and 4 female, of mean age 72 years (range 60–83). Five patients underwent trabeculectomy with mitomycin C (0.02%), which was combined with phacoemulsification cataract extraction in one; two underwent Ahmed glaucoma valve implantations, and one underwent ab-interno Xen45 gel stent implantation with mitomycin C (0.02%). The mean intraocular pressure was 26.0 ± 7.65 mmHg preoperatively, dropping to 6.9 ± 2.64 mmHg on first postoperative day one. Mean time from surgery to diagnosis of choroidal detachment was 11.6 ± 5.73 days. Ciliary body detachment was identified by ultrasound biomicroscopy in all patients, ranging between one and four quadrants. All patients were treated with topical steroids and cycloplegics; three (37.5%) received oral steroids. No surgical intervention for the choroidal or ciliary body detachments was indicated.ConclusionsIn this real-world prospective study, concurrent ciliary body detachment was identified in all patients who presented with choroidal detachment following glaucoma surgery. This observation may deepen our understanding of the mechanism underlying the hypotony that is often seen after glaucoma surgery.

Long-term efficacy and safety of XEN-45 gel stent implantation in patients with normal-tension glaucoma

BackgroundMinimally invasive bleb surgery using the XEN-45 gel stent has not been established for the treatment of normal-tension glaucoma (NTG). The main objective of this study was to evaluate the long-term treatment efficacy and safety of XEN-45 in eyes with uncontrolled NTG.MethodsA retrospective analysis of patients with NTG who underwent XEN-45 gel stent implantation at university hospital Tuebingen between 2016 and 2021. The primary outcome measure was surgical success after three years defined as lowering of intraocular pressure (IOP) of ≥ 20%, with target IOP between 6 and 15 mmHg. Success was complete without and qualified irrespective of topical antiglaucoma medication use. The need for further glaucoma surgery, except for needling, was regarded as a failure. The secondary outcome measures included changes in mean IOP, number of antiglaucoma medications, and needling and complication rates.ResultsTwenty-eight eyes from 23 patients were included in the final analysis. Complete and qualified success rates were 56.5% and 75% after three years, respectively. Mean postoperative IOP ± standard deviation decreased significantly after three years from 19.3 ± 2.0 mmHg at baseline to 13.7 ± 4.2 mmHg (n = 22; p < 0.0001). The median number of antiglaucoma medications decreased from 2 (range 0–4) to 0 after three years (range 0–3; p < 0.0001). Sixteen eyes (57%) required a median of 1 (range 1–3) needling procedures. One eye required further glaucoma surgery. No sight-threatening complications were observed.ConclusionThe XEN-45 stent is effective and safe for the long-term treatment of NTG. However, needling was frequently required to improve outcomes.

Matched case-control comparison of surgical success after XEN45 Gel Stent and PRESERFLO MicroShunt implantation in a Caucasian population.

The aim of this study was to compare the outcome of implantation of a XEN45 Gel Stent with the outcome of implantation of a Preserflo MicroShunt in a matched-pair analysis in eyes being naïve to filtering surgery. In this comparative, retrospective study, 50 eyes that had undergone XEN45 Gel Stent implantation were compared with 50 eyes after Preserflo implantation. Follow-up was at least 6 months, and surgical success was measured by criteria A (IOP < 21 mmHg, IOP reduction >20%, no repeat surgery); criteria B (IOP < 18 mmHg, IOP reduction >20%, no repeat surgery); and criteria C (IOP ≤15 mmHg, IOP reduction ≥40%, no repeat surgery). After a follow-up period of 12 months, mean IOP had decreased from preoperative 25.2 ± 4.8 mmHg in the XEN group to 14.5 ± 4.0 (n = 35) and from 25.3 ± 6.8 mmHg to 11.9 ± 2.9 (n = 41) in the Preserflo group, respectively. The IOP at the last follow-up of the two groups differed significantly (p < 0.01). The probability of surgical success did not differ concerning Criteria A and B, but surgical success was significantly higher in the Preserflo group for Criteria C (60%, p < 0.01). Both the Preserflo and XEN45 Gel Stent provide an effective and safe treatment option for advanced glaucoma and have a high potential to reduce intraocular pressure. Absolute IOP levels of <16 mmHg after 12 months were significantly more frequent in the Preserflo group.

Xen-DS: a novel technique of ab externo Xen implantation augmented with a modified deep sclerectomy for surgical treatment of glaucoma.

The Xen gel stent is a surgical glaucoma device which creates a subconjunctival filtering bleb, which has demonstrated good intraocular pressure (IOP) lowering and safety. Nonetheless, bleb-related problems have been reported. We present a case series of ab externo Xen procedures augmented with a deep intra-scleral lake, aiming to improve both IOP-lowering and post-operative management. A retrospective review of 20 patients who underwent combined Xen gel stent implantation with modified deep sclerectomy at our institution from June to November 2022, with a 6-month follow-up period. We reviewed demographics, past ocular history, visual acuity (VA), IOP, visual fields, glaucoma medication use, complications, and perioperative information. 20 eyes of 20 patients, with a mean age of 67.45 ± 14.38 underwent surgery. Pre-operative initial IOP was 24.5 ± 7.96 mmHg, improving to 11.50 ± 2.96 mmHg at 6 months; a change of -12.89 ± 8.34 mmHg and a mean decrease of 51.13 ± 20.15% (p < 0.0001) Patients were on 3.1 ± 0.72 glaucoma medications pre-operatively, improving to 0.72 ± 1.27 at 6 months (p < 0.0001). Visual field mean deviation was -13.99 ± 9.98 dB pre-operatively and -10.27 ± 9.06 dB at 6 months, with VA of 0.287 ± 0.69 pre-operatively and 0.31 ± 0.76 LogMAR post-operatively. No patients required bleb needling. 2 patients underwent subsequent bleb revision surgery. 2 patients developed choroidal effusions, which were managed conservatively with good visual outcomes. In this preliminary study, we have found the modification of Xen gel stent implant surgery with a modified deep sclerectomy to offer good IOP lowering, with low rates of bleb needling and a good safety profile.

Clinical study on the efficacy and safety of glaucoma drainage implants in the treatment of different types of glaucoma

Objective: To evaluate the efficacy and safety of glaucoma drainage implants(XEN-45 Gel Stent) for glaucoma treatment. Methods: A prospective study was conducted to continuously collect the clinical data of patients who were diagnosed with glaucoma and underwent XEN-45 Gel Stent implantation in the Ophthalmology Department of Peking University People's Hospital from January 2022 to August 2023. The visual acuity, intraocular pressure, number of glaucoma medications, and success rate of the patients were analyzed before and after surgery at 1 day, 1 week, 1 month, 3 months, 6 months, 12 months, and 18 months. The differences in intraocular pressure and number of glaucoma medications among primary open-angle glaucoma, primary angle closure glaucoma, secondary glaucoma, and different implantation methods of XEN-45 Gel Stent among patients with primary open-angle glaucoma were compared. The intraoperative and postoperative complications were observed, and the risk factors for needling and surgical complete success were analyzed. Results: A total of 48 eyes from 48 patients were included in this study, comprising 27 males and 21 females, with a mean age of (54.4±18.0) years and the disease duration was 36.0(7.3, 81.0) months.There were 28 cases of primary open-angle glaucoma, 4 cases of primary angle closure glaucoma, and 16 cases of secondary glaucoma.The follow-up period was 8.0 (3.0, 12.0) months. At 12 months after surgery, the intraocular pressure decreased from 20.5 (17.0, 26.0) mmHg to (13.5±3.3) mmHg (P<0.05), and the number of glaucoma medications decreased from 3.0 (3.0, 4.0) to 0.0 (0.0, 0.0) (P<0.05). The complete success rate and qualified success rate were 73.9% (17/23) and 91.3% (21/23), respectively. The most common postoperative complications were shallow anterior chamber in 6 cases (12.5%), hypotony in 3 cases (6.3%), and blocked stent in 3 cases (6.3%). The most common postoperative treatment was needling in 27 cases (56.3%). There was no significant difference in intraocular pressure among different types of glaucoma. In the comparison of postoperative effects of different surgical implantation methods for primary open-angle glaucoma, there were no statistically significant differences in intraocular pressure and the number of glaucoma medications at other follow-up time points except 1 month after surgery (P<0.05). Univariate logistic regression analysis did not find any risk factors associated with needling and surgical complete success. Conclusions: XEN-45 Gel Stent implantation is an effective and safe surgical option for different types of glaucoma patients in China, which can significantly reduce intraocular pressure and the use of glaucoma medications and has a high success rate. However, some patients may need needling or other treatments after surgery.

Histopathological findings of failed blebs after microinvasive bleb surgery with the XEN Gel Stent and Preserflo MicroShunt

PurposeThe success of XEN Gel Stent (XEN) and Preserflo MicroShunt (Preserflo) implantation depends mainly on the development of bleb fibrosis. This study aimed to describe the histological findings of bleb fibrosis after XEN and Preserflo surgery.MethodsThis retrospective study included patients with different types of glaucoma who underwent revision surgery after XEN or Preserflo implantation. The available clinical information and histological samples of removed fibrotic tissue were analyzed.ResultsThirty-six patients were included. Revision surgery was performed at a median of 195 (range = 31–1264) days after primary surgery. The mean intraocular pressure changed from 29.1 (± 10.3) mmHg at baseline to 18.3 (± 8.7) mmHg (− 37%; p < 0.0001) and 16.2 (± 4.2) mmHg (− 45%; p < 0.0001) after 6 and 12 months, respectively. Histological analysis revealed an increase in activated fibroblasts and macrophages in all specimens and a parallel orientation of fibroblasts in a minor part of the probe in 60% of the specimens. No pronounced inflammatory reaction in the form of lymphocytic or granulocytic infiltration was observed. The comparison of specimens from uveitic glaucoma and primary open-angle glaucoma patients revealed no significant differences.ConclusionsThe histological analysis of fibrotic blebs from the XEN and Preserflo implants did not show any pronounced immune or foreign-body reaction and revealed a similar histological pattern of failed blebs after trabeculectomy.

Three-year clinical outcome of XEN45 Gel Stent implantation versus trabeculectomy in patients with open angle glaucoma

ObjectiveTo reliably compare the three-year clinical outcome and safety of XEN45 Gel Stent implantation (XEN) vs. trabeculectomy (TRAB) in patients with glaucoma.Subject/methodsWe conducted a retrospective cohort study with patients with primary open angle or pseudoexfoliation glaucoma with uncontrolled intraocular pressure (IOP) undergoing XEN or TRAB at the Innsbruck University Clinic of Ophthalmology and Optometry, Austria and analysed changes in IOP, numbers of IOP-lowering medications, and complete surgical success (i.e., IOP ≤ 18 mmHg, ≥20% IOP reduction and not requiring IOP-lowering medication) up to 36 months postoperatively.ResultsBetween 2013 and 2019, we performed XEN Gel Stent implantation in 58 eyes and trabeculectomy in 84 eyes. From baseline to 36 months, mean IOP decreased from 23.4 to 13.8 mmHg (mean reduction 35%, 95% confidence interval 23–48%, p < 0.001) in the XEN group and from 25.1 to 11.2 mmHg (mean reduction 50%, 41–60%, p < 0.001) in the TRAB group. TRAB provided higher IOP reduction than XEN Gel Stent implantation at 12, 24, and 36 months (all p < 0.05). In XEN versus TRAB, IOP-lowering medication was required by 98.3% vs. 97.6% before surgery (p = 0.781), differed significantly at month 12 (43.2% vs. 2.0%, p < 0.001)but not at month 24 or 36. Complete surgical success was achieved in 40.0% vs. 62.8% at month 24 (adjusted odds ratio 2.70; 1.04–7.00, p = 0.040) and 27.3% vs. 56.8% at month 36 (4.36; 1.25–15.18, p = 0.021).ConclusionCompared to XEN, TRAB was associated with lower intraocular pressure, less IOP-lowering medication, and higher probability of achieving complete surgical success over a 36-month follow-up period.

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

This study was aimed to summarize the complications and their management associated with XEN gel stent implantation. 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. 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. 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.

Results of XEN45 Gel Stent Implantation in the Treatment of Primary Open‐Angle Glaucoma Using 5, 10 or 20 μg Mitomycin C: A Pilot Study

Background: No consensus has been reached on the adequate dose of mitomycin C (MMC) in XEN45 gel stent implantation. Lower doses have the potential to reduce MMC‐linked side effects. This study aimed to evaluate treatment efficacy of ab interno XEN45 gel stent in primary open‐angle glaucoma (POAG) with three different MMC doses.Methods: This retrospective single‐centre nonrandomised trail included 54 patients (56 eyes) who underwent XEN45 gel stent implantation for POAG with above‐target intraocular pressure (IOP) under medical therapy. Eyes were grouped according to the received MMC dose: Group 1 (20 μg; n = 21), Group 2 (10 μg; n = 14) and Group 3 (5 μg; n = 21). The primary endpoint was the mean IOP change in the three MMC dose groups after 6, 12 and 24 months. Secondary endpoints included the success rate defined as lowering of baseline IOP ≥ 20% and below a cut‐off IOP set at three different levels: ≤ 18, ≤ 16 and ≤ 14 mmHg (Criteriums 1, 2 and 3), the mean number of ocular hypotensive medications and the frequency of needling procedures.Results: After 24 months, the overall mean (standard error) IOP was significantly reduced from 24.7 (0.9) mmHg to 15.2 (0.7) mmHg (p &lt; 0.0001). The average IOP change (standard error) in MMC dose groups 1, 2 and 3 was −8.6 (2) mmHg, −10.1 (2.1) mmHg and −10.4 (2.8) mmHg. Complete success (Criterium 1) was achieved in 50%, 62% and 43% of the eyes in groups 1, 2 and 3. No statistically significant difference was found within the first 24 months between the three MMC dose groups for IOP change, success rate, number of ocular hypotensive medications and the frequency of needling procedures.Conclusions: XE45 was effective in all three dose groups. As the success rate did not significantly differ between the MMC doses, these results may support the use of the lowest dose.Trial Registration: ClinicalTrials.gov identifier: 559/2016BO2

Combined versus standalone XEN45 Gel Stent implantation in either phakic or pseudophakic patients: a case-matched study

PurposeTo determine differing outcomes among either phakic or pseudophakic patients who received standalone XEN45 Gel Stent (Allergan, an AbbVie Company, CA, USA) implantation and patients who underwent combined surgery with phacoemulsification.MethodsThis retrospective single-center study involved 180 eyes of 180 participants who underwent XEN45 Gel Stent implantation, of which 60 eyes received combined surgery with phacoemulsification (combined group). Standalone stent implantation was performed on 60 phakic (phakic group) and on 60 pseudophakic eyes (pseudophakic group). The groups were matched in a ratio of 1:1:1 based on multiple criteria. Successful surgery was defined by three scores: IOP at the longest follow-up of < 21 mmHg (Score A) or < 18 mmHg (Score B) and an IOP reduction > 20% or IOP ≤ 15 mmHg and an IOP reduction ≥ 40% (Score C). In all scores, one open conjunctival revision was allowed, and additional repeat surgery was considered a failure.ResultsAfter an average follow-up time interval of 20.6 ± 12.6 months, there was a mean IOP-reduction by 37% among the entire cohort. Comparative analysis between the three groups did not show significant differences regarding postoperative IOP, postoperative medication score, side effects, revision rate, repeat surgery rate or success rate. A dysfunctional stent was detected in eight eyes (4%) during open conjunctival revision in 76 eyes.ConclusionThe clinical endpoints investigated did not differ significantly among either phakic or pseudophakic patients who received standalone stent implantation and patients who underwent combined surgery. However mean latency between primary stent implantation and first revision surgery after combined surgery was markedly shorter.

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.

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

BackgroundXen 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 presentationA 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.ConclusionIf 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.

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

BackgroundTo 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 presentationA 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.ConclusionsAlthough 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.

Five-Year Outcomes of Single Trabecular Microbypass Stent (iStent®) Implantation with Phacoemulsification in Korean Patients.

This study reports the long-term intraocular pressure (IOP)-lowering efficacy and safety of a singletrabecular microbypass stent(iStent®; Glaukos Corp., San Clemente, CA, USA) for medically controlled open-angleglaucoma in Korean patients. This retrospective observational study included 42 eyes of 35 patients with primary open-angle glaucoma (POAG). All subjects underwent single first-generation iStent® implantation with phacoemulsification by a single surgeon with 5years follow-up. The primary outcomes were changes in IOP and the number of antiglaucoma medications compared to the preoperative values. The secondary outcome was the proportion of eyes with IOP ≤ 18mmHg without medication, ≤ 15mmHg without medication, and ≤ 18mmHg with or without medication. Adverse events and need for secondary glaucoma surgery were also recorded. The mean IOP decreased from 15.8 ± 2.8 to 13.8 ± 1.7mmHg and the mean number of medications was reduced from 2.24 ± 1.18 to 0.83 ± 1.12, respectively, at year5. At 3 and 5years, 80.6% and 78.6% of eyes, respectively, were receiving fewer medications than preoperative numbers. In contrast, only 50% of eyes on four preoperative medications showed medication reductions at 5years. At years3 and 5, 61.3% and 53.5% of eyes achieved IOP ≤ 18mmHg without medication, whereas 90.3% and 89.3% of eyes achieved ≤ 18mmHg regardless of medication use, respectively. Four eyes required additional glaucoma surgery (two Ahmed glaucoma valve implantations, one trabeculectomy, and one XEN45 Gel Stent implantation), and all were receiving four preoperative antiglaucoma medications. Transient IOP elevation (14.3%) was the most common complication, followed by five hyphema, one stent obstruction, one stent malposition, and one severe anterior chamber reaction. This study demonstrated a good safety profile and sustained IOP reduction after the implantation of a single trabecular microbypass stent (iStent®) with phacoemulsification in Korean patients. The majority of subjects with POAG showed a relatively good response; however, eyes receiving a higher number of medications preoperatively (especially four medications) had difficulty achieving a low target IOP.