Gel Stent Research Articles

XEN Gel Stent Versus Non-penetrating Deep Sclerectomy in Ocular-hypertension and Open-angle Glaucoma Patients.

XEN gel-stent and non-penetrating deep sclerectomy, either alone or in combination with cataract surgery, significantly lowered the intraocular pressure and reduced the number of antiglaucoma medications in open-angle-glaucoma patients; with no significant differences between them. To compare the surgical outcomes of XEN45-implant and non-penetrating deep sclerectomy (NPDS), either alone or in combination with cataract surgery, in patients with ocular-hypertension (OHT) and open-angle glaucoma (OAG). Retrospective and single center cohort study conducted on consecutive patients who underwent a XEN45 implant or a NPDS, either alone or in combination with phacoemulsification. The primary endpoint was the mean change in intraocular pressure (IOP) from baseline to the last follow-up visit. One hundred twenty-eight eyes, 65 (50.8%) eyes in the NPDS-group and 63 (49.2%) eyes in the XEN-group, were included in the study. The mean preoperative IOP was significantly lowered from 17.6±5.3mmHg and 17.8±6.2mmHg to 12.6±2.6mmHg and 13.8±2.8mmHg at month-12, in the XEN and NPDS groups, respectively; P<0.0001 each. At month-12, 70(54.7%) eyes were classified as success, with no significant differences between XEN (57.1%; 36/63 eyes) and NPDS (52.3%; 34/65 eyes) (mean difference: 4.8%; 95% CI: -30.5% to 20.8%; P=0.7115). The number of ocular hypotensive medications was significantly reduced in the XEN (from 2.1±0.7 to 0.2±0.5, P<0.0001) and in the NPDS (from 2.0±0.8 to 0.3±0.6, P<0.0001) groups, with no significant differences between them (P=0.2629). The incidence of postoperative adverse events in the overall study population was 12.5%, with no significant differences between groups (P=0.1275). Seven (11.1%) eyes underwent needling (XEN-group) and 10 (15.4%) goniopuncture (NPDS-group); P=0.4753. XEN45-implant and the NPDS, either alone or in combination with cataract surgery, significantly lowered IOP and reduced the number of ocular hypotensive medications in OHT and OAG patients.

XEN gel stent ® in the management of glaucoma: preliminary results of a tertiary center

Purpose: To analyze the efficacy and safety of a MIGS device (XEN gel stent ®) in the management of glaucoma in our tertiary center. Methods: Retrospective analysis of patients submitted to XEN ® implant alone or combined with cataract surgery. Patients with previous filtering surgeries were included. Intraocular pressure (IOP) was evaluated at 1st week, 1st, 3rd, 6th and 12th months after surgery. BCVA, RNFL thickness and number of antiglaucoma medications were evaluated 1 year after surgery. Early and late complications and need for an additional glaucoma surgery were recorded. Results: Thirty-four eyes from 28 patients were included. The main diagnosis was primary open angle glaucoma (POAG) (58.8%). IOP decreased from 20.5±4.9 mmHg to 15.4±4.1 mmHg 1 year after surgery (p&lt;0.001). There was also a decrease in the number of antiglaucoma medications, from 3.6±0.6 to 0.6±0.7 (p&lt;0.001). BCVA increased from 0.57±0.30 to 0.87±0.18 in the combined surgery group (p=0.03). RNFL thickness remained stable (p=0.558). Hypotony occurred in 2 eyes (5.9%). Two eyes (5.9%) needed another glaucoma surgery in the 1st year of follow-up. Conclusion: According to our results, XEN® alone or combined with phacoemulsification showed to be effective in IOP reduction, with few complications, as a primary surgery or even in eyes with previous filtering surgeries.

Intraocular Pressure and Medication Changes Associated with Xen Gel Stent: A Systematic Review of the Literature.

The Xen gel stent (Allergan Inc, an AbbVie company; Dublin, Ireland) was conceived as an option for patients requiring modest IOP reduction but for whom trabeculectomy was not yet indicated. As with any glaucoma surgery, establishing criteria for patient selection and identifying factors that contribute to a high likelihood of success are important. To help guide clinical decision-making, a systematic review of published studies on the gel stent was performed, with the goal of understanding postoperative outcomes based on clinical and patient factors. Results were organized around a series of pertinent clinical questions based on scenarios encountered in clinical practice. Criteria for including studies were intentionally broad, with the objective of simulating the diverse population of glaucoma patients encountered in real-world practice. Outcomes for IOP and medication reduction postoperatively were assessed in various analyses, including in eyes with various glaucoma types and severity; in eyes naïve to surgery as well as those with a history of prior incisional glaucoma surgery; and when surgery was performed as a standalone procedure or at the time of cataract surgery. The results of each of the various analyses were consistent in demonstrating that successful gel stent surgery achieved a postoperative IOP of approximately 14.0 mm Hg and reduction to fewer than 1 glaucoma medication. Additional data are shown on outcomes by method of implant (ab interno vs ab externo); intraoperative use of antifibrotics; and rates of needling in published studies.

XEN Gel Stent Implantation in Eyes With Previous Glaucoma Filtering Surgeries: A Case Series.

Background In this study, we aimed to analyze the efficacy and safety of ab interno XEN® gel stent (Allergan Inc., Dublin, Ireland) implantation in a series of eyes with open-angle glaucoma and a history of previous filtering glaucoma surgeries. Methodology This retrospective, single-center study included all eyes that underwent XENgel implantation with a minimum follow-up of 18 months that had previously undergone a filtering glaucoma surgery. The main outcomes were intraocular pressure (IOP) variation (baseline, first day, first week, and first, third, sixth, 12th, and 18th months), the number of hypotensive eyedrops at 18 months, intraoperative and postsurgical complications, and the need for subsequent glaucoma surgery. Results A total of 10 eyes from nine patients were enrolled in the study. IOP significantly decreased from 24.0 ± 2.4 mmHg to 7.8 ± 1.6 mmHg on the first day, 9.4 ± 2.2 mmHg in the first week, and 12.3 ± 4.8 mmHg, 14.7 ± 4.3 mmHg, 13.3 ± 3.8 mmHg, 11.7 ± 1.9 mmHg, and 12.3 ± 1.9 at the first, third, sixth, 12th, and 18th month, respectively (p < 0.001), with a 49.5% reduction in IOP at the end of the follow-up. The number of hypotensive eyedrops decreased significantly from 3.5 ± 0.5 (3-4) to 0.7 ± 0.7 (0-2) (p = 0.026). No intraoperative or postsurgical complications were recorded. In total, seven (70%) eyes achieved controlled IOP of <18 mmHg without any anti-glaucomatous medications, and one (10%) eye with the use of topical prostaglandin. One (10%) eye was submitted to a surgical revision, and another needed an additional glaucoma surgery during follow-up, with appropriate IOP control at the last follow-up. Conclusions This case series aims to highlight that the XEN implant can be an option in eyes with IOP levels in the low 20s and previously failed filtering surgeries, with satisfactory efficacy and high safety.

Effect of MIGS on corneal endothelium

AbstractCorneal endothelium is one the meeting points between glaucoma and corneal pathologies. Endothelial cells maintain corneal transparency by dehydrating the cornea, by pumping fluid from the corneal stroma back into the aqueous humour. Loss of these cells leads to fluid accumulation and corneal opacification. Loss of endothelial cells was indeed also observed with trabeculectomy, but it evolved in one of the major issues in the “big tube” glaucoma surgery. Rapid development of new glaucoma surgery techniques in the last decade re‐opened the question in the context of microinvasive suprachoroidal and Schlemm canal techniques. The more classic subconjunctival surgical drainage pathway has observed changes lately as well: collagen gel stent XEN and PreserFlo Microshunt were relatively recently introduced. With these still relatively new techniques, the research focus in the initial stages was placed on intraocular pressure reducing efficacy and general safety. However, in the meantime also research results also on the topic of endothelial cell density following these interventions have been published, and this talk will try to summarize the current knowledge in this area.

Bleb morphology using optical coherence tomography : After primary implantation of XEN gel stent and open conjunctival revision

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. Included were eyes that underwent XEN implantation (Pr-X) or bleb revision after XEN (Re‑X 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. A total of 69eyes (40in the Pr‑X and 29in the Re‑X groups) were included. At the conjunctival level, the most commonM 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 Pr‑X group were hyporeflective and cavernous changes (M-T2, T3) followed by no changes (M0) and hyperflective changes (T1). In the Re‑X group, the M‑T1 and T2 were most commonly seen followed by T3 and T0. The M‑T2 and T3 in the Pr‑X group and the M‑T1 and T2 in the Re‑X group correlated with lower IOP. An episcleral lake (M-ES1) was seen significantly less frequently in the Pr‑X group compared with Re‑X 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.

Reoperations for complications within 90 days after gel stent implantation or trabeculectomy

PurposeTo describe reoperations in the operating room for complications that occurred within the first 90 days after gel stent implantation or trabeculectomy at a single institution over 5 years.MethodsIn this retrospective chart review, patients who have undergone gel stent implantation with mitomycin C (MMC) or trabeculectomy with MMC were enrolled. Postoperative complications that required reoperations within the first 90 days were evaluated.ResultsA total of 510 surgeries were performed on 392 patients over a 57-month period by 2 glaucoma surgeons. Of these, 284 were gel stent implantation, and 226 were trabeculectomy. Combined phacoemulsification was performed in 52/284 (18.3%) in the gel stent group and in 26/226 (11.5%) of eyes in the trabeculectomy group (p = 0.03). Reoperations took place in 13/510 (2.5%) eyes, including 4/284 (1.4%) in the gel stent group, 9/226 (4.0%) in the trabeculectomy group (p = 0.07). In the gel stent group, indications for reoperation were bleb failure (2), suprachoroidal hemorrhage (1), bullous keratopathy (1). In the trabeculectomy group, indications for reoperation were bleb failure (3), overfiltration (2), persistent wound leak (2), aqueous misdirection (2).ConclusionsThe rates of reoperation for early postoperative complications after gel stent or trabeculectomy was low and comparable with previous studies. A slightly higher number of reoperations within 90 days was observed in the trabeculectomy group than the gel stent group despite the more significant number of combined procedures in the latter group. Bleb failure was the most common indications for reoperation in both groups. Excessive outflow was a cause of reoperation mostly in the trabeculectomy group.

Comparison of surgical outcomes with and without Ologen collagen matrix augmentation during XEN gel stent implantation

BackgroundTo compare the surgical outcomes and postoperative complications with and without Ologen collagen matrix augmentation during XEN gel stent implantation.MethodsWe retrospectively analyzed patients who underwent XEN gel stent implantation with an ab externo technique. The amount of intraocular pressure (IOP) reduction, percentage of postoperative complications and additional management, and surgical success defined as IOP reduction greater than 20% compared with the preoperative IOP measurement were compared between Ologen-augmented and non-augmented groups. Groups of patients who underwent XEN gel stent implantation alone and combined with phacoemulsification were analyzed separately.ResultsA total 103 eyes of 103 participants were included. Of those, 72 eyes underwent standalone XEN gel stent implantation: 42 eyes with Ologen augmentation (Oloxen group) and 30 eyes without Ologen augmentation (Xen group). Thirty-one eyes underwent XEN gel stent implantation with phacoemulsification: 19 eyes with Ologen augmentation (Phaco-Oloxen group) and 12 eyes without Ologen augmentation (PhacoXen group). The surgical success rate at six months postoperatively was not different between the Oloxen and Xen groups (56.4% vs 43.3%, P > 0.05) or between the Phaco-Oloxen group and PhacoXen group (57.9% vs 41.7%, P > 0.05). The prevalence of postoperative hypotony, 5-fluorouracil injections, use of anti-glaucoma medications, bleb needling, and additional glaucoma surgeries was not different between the Oloxen and Xen groups or between the Phaco-Oloxen and PhacoXen groups when assessed six months postoperatively.ConclusionsAll groups showed significant IOP reduction after XEN gel stent implantation, but there was no significant difference between the Ologen collagen matrix augmented and non-augmented groups in surgical outcomes.

Effectiveness of Microinvasive Glaucoma Surgery in the United States: Intelligent Research in Sight Registry Analysis 2013–2019

To evaluate the effectiveness of microinvasive glaucoma surgery (MIGS) with and without concurrent phacoemulsification. Multicenter, retrospective cohort study. Patients in the Intelligent Research in Sight (IRIS®) Registry who underwent Xen gel stent (ab interno) implantation, endoscopic cyclophotocoagulation (ECP), or goniotomy or canaloplasty from 2013 through2019. Kaplan-Meier survival analysis was used to assess reoperation rates. We defined reoperation as any subsequent glaucoma surgery occurring 1 month to 3 years after the initial procedure. Multivariable Cox proportional hazard models were used to determine factors predictive of reoperation. Reoperation rate, mean intraocular pressure (IOP) and visual acuity (VA), postoperative complications, predictors of reoperation, and reoperation procedure type. A total of 79 363 eyes from 57 561 patients were included, with 15 118 eyes (19%) receiving stand-alone MIGS and 64 245 eyes (81%) receiving MIGS concurrent with phacoemulsification. Overall, patients who underwent MIGS concurrently with phacoemulsification showed lower reoperation rates compared with stand-alone MIGS, most pronounced in ECP and goniotomy or canaloplasty. At postoperative year 2, the cumulative reoperation rate for stand-alone procedures was 15% for ECP, 24% for Xen implantation, and 24% for goniotomy or canaloplasty compared with 3% for ECP, 19% for Xen implantation, and 6% for goniotomy or canaloplasty concurrent with phacoemulsification (P < 0.001 for each stand-alone MIGS vs. MIGS with phacoemulsification). Black race, older age, moderate and severe glaucoma, higher baseline IOP, and glaucoma subtype were associated with higher reoperation risk. Although IOP decreased in all groups, stand-alone MIGS showed a more substantial decrease in mean IOP. Complication rates from MIGS were low overall: 1% for ECP, 1% for Xen implantation, and 2% for goniotomy or canaloplasty. In current United States clinical practice, MIGS has substantially lower reoperation rates when performed with phacoemulsification, especially for ECP and goniotomy or canaloplasty. Approximately one-sixth of patients undergoing stand-alone ECP and one-quarter of patients undergoing stand-alone Xen implantation or goniotomy or canaloplasty require reoperation by 2 years. Black race, diagnosis coding of moderate to severe glaucoma, and higher baseline IOP were associated with higher risk of reoperation after MIGS procedures. Proprietary or commercial disclosure may be found after the references.

Defining the role of ab externo Xen gel stent in glaucomatous eyes with prior failed surgical intervention

PurposeTo evaluate the safety and efficacy of Xen45 Gel stent (Xen; Allergan) in eyes that have failed prior surgical intervention, compared to traditional glaucoma drainage device (GDD) or continuous-wave cyclophotocoagulation (CPC). Since this population has low expected success rates with additional surgery, it is vital to compare to standard-of-care surgical options.MethodsRetrospective, single-center, case–control study of ab externo transconjunctival Xen shunt in eyes that have previously undergone trabeculectomy and/or GDD surgery. Postoperative data were collected for 18 months. Failure was defined as no light perception, additional glaucoma surgery required, or intraocular pressure (IOP) of < 6 mmHg after 6 weeks postoperatively.ResultsEighteen Xen eyes and 36 control eyes matched on both glaucoma type and previous glaucoma surgeries were included. Seventy-two percent had primary open angle glaucoma, 11% uveitic, 6% primary angle closure, 6% pseudoexfoliation, and 6% pigmentary glaucoma. Fifty-six percent of eyes in each group had prior trabeculectomy, 28% of Xen and 31% of control eyes had prior GDD, and 17% of Xen and 14% of control eyes had both. Baseline medicated IOP was lower in the Xen group (21.8 ± 7.2) compared to controls (27.5 ± 9.4, P = 0.043). The cumulative failure rate at year 1 was 17% for Xen and 20% for controls (P = 0.57). Mean survival time was 14.1 (± 1.5) months and 11.4 (± 0.6) months for controls. There was no difference in minor complication rates between groups (P = 0.65), but the Xen group had a significantly lower rate of serious complications (P = 0.043) defined as vision threatening or requiring surgical intervention in the operating room. When censored for additional glaucoma procedures, there were no differences at year 1 in IOP, change in IOP, number of IOP-lowering medications, or number of medications reduced from baseline.ConclusionsThe Xen shunt provides a reasonable alternative to current standard of care, with a similar failure rate at year 1, with a noninferior IOP reduction compared to GDD and CPC, and a preferred safety profile.

Italian Candidates for the XEN Implant: An Overview from the Glaucoma Treatment Registry (XEN-GTR).

Background The Italian XEN Glaucoma Treatment Registry (XEN-GTR) was created to acquire a comprehensive prospective dataset that includes the patient characteristics, intraoperative variables, and postoperative management of glaucoma patients undergoing the XEN gel stent implantation. Methods This was a prospective observational, longitudinal clinical study involving 10 centres throughout Italy. The baseline examination included a comprehensive evaluation of demographic parameters (age, sex, ethnicity, and systemic condition), specific ophthalmological parameters, and quality of life questionnaire score collection. Results The baseline data of 273 patients were analysed. The median (IQR) age was 72 (65.0 to 78.0) years. Of the 273 patients, 123 (45%) were female and 150 (55%) were male. A total of 86% of the patients had open-angle glaucoma with a mean intraocular pressure of 24 ± 6 (range 12.0–60.0) mmHg. The mean number of medications was 2.7 ± 0.9 at baseline for the patients with a prevalence of prostaglandin analogues combined with a beta-blocker and anhydrase carbonic inhibitor (31.8%). The mean scores of the NEI-VFQ 25 and GSS questionnaires were 78 ± 18 (range 26.5–100) and 85 ± 14 (range 79–93), respectively. Combined XEN/cataract surgeries were scheduled in 73.7% of the patients. The preferred place for the XEN implant was the supero-nasal quadrant (91.6%). Conclusions Observing the baseline characteristics of the typical Italian candidates for the XEN gel implant shows that they are patients affected by POAG and cataracts, with moderate to severe glaucoma damage, all of which has an impact on their quality of life.

Ab Interno XEN Gel Stent Implantation in Eyes with Previous Tube Shunt Surgery.

PurposeAfter tube shunt surgery, many factors may contribute to insufficient filtration over time, prompting further intervention to achieve optimal intraocular pressure (IOP) control. This study explores whether ab interno XEN gel stent implantation could be a viable approach in eyes that need further IOP reduction after tube shunt surgery.MethodsThis is a retrospective, single-surgeon case series on ab interno XEN45 gel stent implantation in eyes that had previous tube shunt surgery. Main outcome measures were IOP and number of glaucoma medications at the pre-operative visit, post-operative week (POW) 1, and post-operative month (POM) 1, 3, 6, and 12. Adverse events and further interventions were noted. Surgery outcome was qualified as absolute success (IOP ≤ 18mmHg or ≥ 20% IOP reduction without glaucoma medications), qualified success (IOP ≤ 18mmHg or ≥ 20% IOP reduction with glaucoma medications), or failure (IOP > 18mmHg and < 20% IOP reduction with maximum tolerated glaucoma medications).Results7 eyes from 6 patients were included in this study. IOP was reduced from 23.9 ± 5.3 mmHg (mean ± standard deviation) pre-operatively to 14.0 ± 5.3 mmHg at POM12 (p < 0.05). Number of glaucoma medications was reduced from 4.3 ± 1.3 pre-operatively to 1.6 ± 1.6 at POM12 (p < 0.05). Hypotony and choroidal effusion were noted in one case which resolved before POM1. Bleb needling was required in 3 of the 7 eyes (43%), with one eye requiring needling twice. By POM12, 2 of 7 eyes (29%) achieved absolute success, 4 eyes (57%) qualified success, and 1 eye (14%) was qualified as failure.ConclusionAb interno XEN gel stent can effectively reduce IOP and number of glaucoma medications after failed tube shunt surgery. Nonetheless, further interventions such as bleb needling may still be required to optimize IOP control.

One-Year Outcomes of Standalone XEN Gel Stent Versus Nonpenetrating Deep Sclerectomy.

The nonpenetrating deep sclerectomy (NPDS) procedure resulted in significantly more surgical success than the standalone XEN gel stent procedure without differences in safety profile. The purpose of this study was to compare surgical success and safety profile of NPDS and XEN gel stent. A retrospective chart review of 328 eyes of 282 patients who were scheduled for standalone XEN gel stent surgery (n=140) or NPDS (n=188) at Groupe Hospitalier Paris Saint-Joseph between January 2017 and December 2018 was conducted. Primary outcome measure was the proportion of surgical success 12 months after surgery. Complete and qualified surgical successes were defined by intraocular pressure (IOP)≤18mmHg and a reduction of IOP≥20% without or with hypotensive medication, respectively. In total, 82 eyes were included in the XEN group and 124 eyes in the NPDS group. In the 1-eye analysis, rates of "complete success" and "qualified success" were, respectively, at the end of follow-up, 28.57% and 20.00% in the XEN group, and 42.72% and 16.50% in the NPDS group ( P =0.17). Success probability plots based on the Kaplan-Meier estimate for overall surgical success demonstrated a median success probability time of 3.73 years for the NPDS group and 2.38 years for the XEN group ( P <0.0001). After adjustment for confounding variables using Cox regression, the NPDS procedure was significantly more associated with surgical success than the XEN gel stent implantation ( P <0.001). No difference was demonstrated in terms of reduction of antiglaucoma medications, needling procedures, or reoperations. The NPDS procedure may be more effective than the XEN gel stent in reducing IOP in patients with open angle glaucoma and may result in longer surgical success. However, a well-conducted prospective randomized study is required to confirm these results.

Glaucoma medical treatment as a predictor of XEN45 subconjunctival gel implant hypotensive efficacy.

The aim of this study was to determine the preoperative characteristics influencing hypotensive efficacy of the XEN45 gel stent in patients with open-angle glaucoma at one-year follow-up. This was a retrospective multicentre study. All patients who underwent XEN45 gel stent implantation between January 2017 and January 2021 were included. The main study outcome was the assessment of one-year postoperative intraocular pressure (IOP) and glaucoma medication differences according to the number and type of preoperative topical treatments or glaucoma surgery, glaucoma stage and time since diagnosis. Follow-up period was 1-year post-surgery in all cases. IOP reduction and surgery success (not requiring reoperation or pressure failures [IOP > 18mmHg and < 20% reduction in IOP]), safety and cost savings in topical glaucoma therapy after surgery were secondarily assessed. Linear regression analysis to determine the preoperative parameters influence on 1-year postoperative results was performed. XEN45 gel stent was implanted in 85 patients. One-year postoperative mean IOP dropped from 20.6 ± 4.1 to 13.7 ± 2.8mmHg (p < 0.0001). Likewise, mean number of topical treatments decreased from 2.05 ± 0.9 to 0.36 ± 0.65 (p < 0.001). Both were mainly influenced by the number of preoperative glaucoma treatments, such that for each one-glaucoma medication increase, postoperative intraocular pressure increased by 1.18mmHg (95% CI 0.56-1.79, p < 0.0001) and number of glaucoma medications increased by 0.3 (95% CI 0.16-0.43, p < 0.001). Overall success rates (with and without supplemental glaucoma medication use) were 97.6% (95% CI 94.5-100%), 87.1% (95% CI 80.2-87.1%) and 61.2% (95% CI 51.6-72.5%) at 3, 6months and 1year after surgery. No sight-threatening adverse events were reported. Mean annual cost savings on medical treatment since surgery reached EUR 251.19 ± 169. 93 euros. One year after surgery, XEN45 gel implant significantly reduced IOP and number of topical medications with an adequate safety profile being both mainly influenced by the number of preoperative glaucoma treatments.

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.

Implantation du dispositif XEN 45® dans la chirurgie du glaucome : étude bicentrique bispective s’intéressant au glaucome cortisonique par rapport au glaucome primitif à angle ouvert

XEN 45® gel stent is an ab interno aqueous humor drainage device indicated for moderate glaucoma refractory to medical management. Its efficacy has been demonstrated in primary open-angle glaucoma (POAG). However, there are few studies on secondary glaucoma, including steroid-induced glaucoma (CG), defined as optic neuropathy induced by using local or systemic corticosteroids without increased flare. We conducted a dual-center comparative cohort study between April 2019 and January 2021. 66 operated eyes were included, divided into two groups: POAG (56 eyes) and GC (10 eyes). The primary endpoint was the relative reduction in intraocular pressure (IOP) at three months postoperatively in the GC group. Three outcomes were defined: total success, partial success and failure. The total success rate was 100% in the GC group and 42.6% in the POAG group. Preoperative IOP was 36.1±9.1mmHg and 19.0±7.3mmHg respectively. IOP reduction was 69.1±11.7% in the GC group and 21.8±30.3% in the POAG group. Patients were younger in the GC group (49.3±21.2 versus 71.1±8.4 years), and preoperative conjunctival preparation was longer in this group (12 versus 5 weeks). The needling rate was 17.9% in the POAG group and 10% in the GC group. The XEN 45® gel stent is effective in the treatment of steroid-induced glaucoma. Further studies will be required to identify predictive factors for success and to establish criteria for good candidacy.

The efficacy of XEN gel stent implantation in glaucoma: a systematic review and meta-analysis

BackgroundXen is a device for minimally invasive glaucoma surgery, and is used to treat POAG, pseudoexfoliative or pigmentary glaucoma, as well as refractory glaucoma. The efficacy of XEN in treating glaucoma remains to be confirmed and clarified. Hence, we conducted a systematic review and meta-analysis to examine the efficacy and associated complication of XEN implantations.MethodsWe conducted a literature search in PubMed, EMBASE, the Cochrane Library of Systematic Reviews, Web of Science, China National Knowledge Infrastructure, WanFang and SinoMed databases to identify studies, published before May 15, 2021, which evaluated XEN in glaucoma, and parameters for measurements included intra-ocular pressure (IOP), number of anti-glaucoma medications (NOAM), and bleb needling rate. We compared the measurements of XEN-only procedure between phaco-XEN and trabeculectomy, and we also did sub-analysis based on time points, glaucoma types, ethnics, etc. Sensitivity analyses and publication bias were conducted for evaluating bias.This study followed the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA 2020) reporting guideline.ResultsWe identified 78 eligible studies, analysis revealed obvious IOP reduction after XEN stent implantation (SMD: 1.69, 95% CI 1.52 to 1.86, p value < 0.001) and NOAM reduction (SMD: 2.11, 95% CI 1.84 to 2.38, p value < 0.001). Sub-analysis showed no significant difference with respect to time points, ethnicities, and economic status. No significant difference was found between XEN treatment effect on POAG and PEXG eyes and between pseudo-phakic and phakic eyes. Also no significant difference was found between XEN and phaco-XEN surgery in terms of IOP after surgery (SMD: -0.01, 95% CI -0.09 to 0.08, p value 0.894). However, NOAM (after publication bias correction) and bleb needling rate (RR: 1.45, 95% CI 1.06to 1.99, p value 0.019) were lower in phaco-XEN group compared to XEN only group. Compared to trabeculectomy, XEN implantation had similar after-surgery IOP, however bleb needling rate (RR: 2.42, 95% CI 1.33 to 4.43, p value 0.004) was higher.ConclusionOur results confirmed that XEN is effective in lowering both IOP and NOAM till 48 months after surgery. It is noteworthy that XEN implantation leads to higher needling rate, compared to phaco-XEN or trabeculectomy. Further research, studying complications of XEN on non-European ethnicities, especially on Asian, are in urgent need before XEN is widely applied.

Clinical Outcomes of Ab Interno Placement versus Ab Externo Placement of XEN45 Gel Stents

To compare the effectiveness of ab interno versus ab externo placement of XEN45 gel stents in patients with open-angle glaucoma. Single-center, noncontrolled, retrospective, comparative case series. Eighty-nine eyes of 89 patients with open-angle glaucoma who underwent XEN45 gel stent implantation. Patients underwent either ab interno (group 1) or ab externo (group 2) placement of a XEN45 stent between 2017 and 2020 by a single surgeon. Outcomes were recorded at each follow-up visit from postoperative day 1 up to 24 months, with median follow-up lengths of 12 months and 8 months for groups 1 and 2, respectively. The primary outcome measure was the surgical success rate at 8 months. Secondary measures were postoperative intraocular pressure (IOP) and medication usage, complication rates, and bleb revision rates. Success rates at 8 months were 72% in group 1 (n= 29) and 74% in group 2 (n= 60). There was no difference in the median time to failure between groups (P= 0.98). The mean baseline IOPs were 22.8 ± 7.5 on 3.8 ± 0.9 medications in group 1 and 25.3 ± 10.7 on 3.7 ± 1 medications in group 2. At the last follow-up among eyes with surgical success, the mean IOPs were 12.5 ± 3.8 on 2.2 ± 1.4 medications in group 1 and 12.2 ± 2.1 on 1.8 ± 1.3 medications in group 2. The adjusted mean IOPs and numbers of medications used were significantly lower after XEN45 stent implantation at all postoperative time points compared with baseline in both groups (P < 0.05). There were no significant differences in postoperative adjusted mean IOPs or medications used between the groups at any of the follow-up time points. Complication rates and bleb revision rates were comparable between both groups (P > 0.05). The ab externo approach of XEN45 stent placement demonstrates comparable effectiveness to the ab interno approach in patients with open-angle glaucoma, although this study was underpowered to detect a difference in success rates between groups.

Comparison of Clinical Outcomes Following Gel Stent Implantation via Ab-Externo and Ab-Interno Approaches in Patients with Refractory Glaucoma.

PurposeTo compare clinical outcomes following gel stent implantation via ab externo and ab interno approaches in patients with refractory glaucoma.Patients and MethodsThis retrospective study included 203 eyes of 185 patients aged ≥45 years who underwent Xen gel stent implantation as a standalone procedure for medically uncontrolled glaucoma (intraocular pressure (IOP) ≥18 mmHg) despite maximum tolerable IOP-lowering medications. One hundred and five eyes underwent gel stent implantation via ab interno approach and 98 via ab externo. Patients with prior conjunctival-incisional glaucoma or cataract surgery were also included. Study parameters were reduction in IOP and number of IOP-lowering medications from baseline to 3, 6, 9 and 12 months postoperatively.ResultsThere were no statistically significant differences in the age, sex, preoperative IOP, number of IOP-lowering medications or cup–disc ratio between the ab interno and ab externo groups at baseline (p > 0.05). At all postoperative time points, mean IOP and percentage reduction from baseline were comparable in both groups (p > 0.05) except at postoperative 6 months when the outcomes were significantly better (p < 0.05) in the ab externo group. The rate of postoperative procedures (5-Fluorouracil injections and bleb needling), the incidence of numerical or clinical hypotony and adverse events were comparable in both groups (p > 0.05). The mean number of IOP-lowering medications was comparable in both groups at all time points.ConclusionThe Xen gel stent, whether implanted ab interno or ab externo, is effective in reducing IOP and dependence on topical medications in eyes with refractory glaucoma. The stent may be used in both phakic and pseudophakic patients and is a reasonable option for patients with prior failed trabeculectomy.

Transconjunctival XEN45 Implantation for Glaucoma Performed at the Slit Lamp: A Pilot Study.

Précis:This pilot study of ab externo implantation of a gel microstent is a novel, minimally invasive glaucoma surgery performed at the slit lamp that is effective for lowering intraocular pressure in patients with uncontrolled glaucoma.Purpose:To evaluate the intraocular pressure (IOP)–lowering effect of gel microstent (XEN Gel Stent, Allergan, Irvine, CA) implantation using an ab externo approach in an office setting.Patients and Methods:This retrospective, multicenter chart review examined outcomes in patients with uncontrolled glaucoma receiving maximally tolerated medical therapy, who underwent slit lamp ab externo gel stent implantation. At postoperative visit, the IOP, the number of glaucoma medications, the final position of the stent, and the needling rate were analyzed. Assessments were conducted 1 day, 1 week and 1, 3, 6, and 12 months after the implantation. Treatment success was defined as IOP ≥6 mm Hg and ≤18 mm Hg with ≥20% reduction from presurgical IOP, with or without medications.Results:Thirty-four eyes from 28 patients were included. Mean preoperative IOP was 24.1±8.0 mm Hg on 3.2±0.9 glaucoma medications. At 12 months postoperative, IOP was reduced to 15.4±4.7 mm Hg on 0.6±1.0 medications; 46.9% and 81.3% of eyes achieved complete and partial success, respectively. The gel stent was properly positioned in 94.1% of eyes after 1 attempt at implantation and in 100% of eyes after a second attempt. In addition to malpositioning, observed complications included occlusion, erosion, and endophthalmitis following anterior chamber reformation. Adjunctive needling was required in 21% of implanted eyes.Conclusion:Slit-lamp-based transconjunctival XEN45 implantation reduced intraocular pressure in glaucoma patients in the first year of this pilot study and was most commonly associated with wound leak and hypotony among other adverse events.