XEN® Gel Stent in Medically Refractory Open-Angle Glaucoma: Results and Observations After One Year of Use in the United States

Effectiveness and safety of XEN45 implant over 12 months of follow-up: data from the XEN-Glaucoma Treatment Registry

OBJECTIVES

To evaluate the 1-year effectiveness and safety of the XEN45, either alone or in combination with phacoemulsification, in glaucoma patients.

METHODS

This multicentre, prospective, observational study included consecutive eyes of glaucoma patients from the Italian XEN-Glaucoma Treatment Registry (XEN-GTR) who underwent XEN45 alone or in combination with phacoemulsification, with at least 1 year of follow-up. Surgical success was defined as intraocular pressure (IOP) < 18 mmHg and ≥20% reduction from preoperative IOP, over 1 year of follow-up.

RESULTS

Two hundred thirty-nine eyes (239 patients) were analyzed, 144 (60.2%) eyes in the XEN-solo and 95 (39.8%) eyes in the XEN+Phaco groups. One hundred-sixty-eight (70.3%) eyes achieved overall success, without statistically significant differences between study groups (p = 0.07). Preoperative IOP dropped from a median (IQR) of 23.0 (20.0-26.0) mmHg to 14.0 (12.0-16.0) mmHg at month 12 (p < 0.001), with overall 39.9 ± 18.3% IOP reduction. The mean number of preoperative ocular hypotensive medications (OHM) was significantly reduced from 2.7 ± 0.9 to 0.5 ± 0.9 at month 12 (p < 0.001). Preoperative IOP < 15 mmHg (HR: 6.63; 95%CI: 2.61-16.84, p < 0.001) and temporal position of the surgeon (HR: 4.25; 95%CI: 2.62-6.88, p < 0.001) were significantly associated with surgery failure. One hundred-forty-six (61.1%) eyes had no intraoperative complications, whereas 91 (38.1%) and 56 (23.4%) eyes experienced at least one complication, respectively early (< month 1) and late (≥ month 1), all self-limiting or successfully treated without sequelae. Needling occurred in 55 (23.0%) eyes at least once during follow-up.

CONCLUSION

Over 1-year follow-up, XEN45 alone or in combination with phacoemulsification, had comparable success rates and effectively and safely lowered IOP and the need for OHM.

Microfluidics in the eye: a review of glaucoma implants from an engineering perspective

Glaucoma is a progressive optic neuropathy in the eye, which is a leading cause of irreversible blindness worldwide and currently affects over 70 million individuals. Clinically, intraocular pressure (IOP) reduction is the only proven treatment to halt the progression of glaucoma. Microfluidic devices such as glaucoma drainage devices (GDDs) and minimally invasive glaucoma surgery (MIGS) devices are routinely used by ophthalmologists to manage elevated IOP, by creating an artificial pathway for the over-accumulated aqueous humor (AH) in a glaucomatous eye, when the natural pathways are severely blocked. Herein, a detailed modelling and analysis of both the natural microfluidic pathways of the AH in the eye and artificial microfluidic pathways formed additionally by the various glaucoma implants are conducted to provide an insight into the causes of the IOP abnormality and the improvement schemes of current implant designs. The mechanisms of representative glaucoma implants have been critically reviewed from the perspective of microfluidics, and we have categorized the current implants into four groups according to the targeted drainage sites of the AH, namely Schlemm's canal, suprachoroidal space, subconjunctival space, and ocular surface. In addition, we propose to divide the development and evolution of glaucoma implant designs into three technological waves, which include microtube (1st), microvalve (2nd) and microsystem (3rd). With the emerging trends of minimal invasiveness and artificial intelligence in the development of medical implants, we envision that a comprehensive glaucoma treatment microsystem is on the horizon, which is featured with active and wireless control of IOP, real-time continuous monitoring of IOP and aqueous rate, etc. The current review could potentially cast light on the unmatched needs, challenges, and future directions of the microfluidic structural and functional designs of glaucoma implants, which would enable an enhanced safety profile, reduced complications, increased efficacy of lowering IOP and reduced IOP fluctuations, closed-loop and on-demand control of IOP, etc.

Minimally Invasive Glaucoma Surgery: Latest Developments and Future Challenges

The development of minimally invasive glaucoma surgeries (MIGSs) was intended to provide safe and modestly efficacious modalities for early intervention of mild-to-moderate glaucoma, with minimal trauma and rapid recovery. They were mainly ab interno procedures that reduce intraocular pressure by facilitating the aqueous outflow by bypassing the trabecular meshwork resistance, reinforcing the uveoscleral flow via the supraciliary space, and reducing aqueous production by the ciliary body. While the cumulating evidence helps shape the role of the available MIGS, the exponential new development and advancement in this field has expanded the territory of MIGS. Apart from developing subconjunctival MIGS filtration devices (Xen gel stent and PRESERFLO MicroShunt), there is a tendency to revisit the "traditional" MIGS for alternative use and to modify the procedures with consideration of the fundamental aqueous outflow physiology. Combined MIGS has also been suggested, based on the theory that their different mechanisms may provide additive or synergistic effects. The advancement of laser procedures is also promising and could supplement unmet needs along the glaucoma treatment algorithm. This review examines the broad array of MIGS, updates the recent findings, discusses their potential alternative applications, and explores future challenges.

All Consecutive Ab Externo SIBS Microshunt Implantations With Mitomycin C: One-Year Outcomes and Risk Factors for Failure

PURPOSE

To present the effectiveness, risk factors for surgical failure, and adverse events over 12 months in a consecutive diverse cohort of glaucoma patients who underwent solo or combined ab externo SIBS microshunt with mitomycin C (MMC) with or without previous subconjunctival surgery.

DESIGN

Retrospective, consecutive, interventional case series.

METHODS

Consecutive glaucomatous eyes on maximally tolerated medical therapy received ab externo SIBS microshunt with MMC implantation as a solo or combined procedure with phacoemulsification from July 2015 to January 2020. The primary outcome was the proportion of eyes at 12-months with the following: (1) no 2 consecutive intraocular pressures (IOPs) >17 mm Hg or clinical hypotony, without (complete success) or with (qualified success) glaucoma medications; and (2) ≥20% reduction from baseline IOP. Secondary outcomes included upper IOP thresholds of 14 and 21 mm Hg with and without a 20% IOP reduction from baseline, median IOP, medications, risk factors for failure, postoperative interventions, complications, and reoperations.

RESULTS

A total of 436 eyes underwent surgery; 86 (20%) combined with phacoemulsification, 127 (29%) in eyes with refractory glaucoma, and 234 (51%) stand-alone procedures in non-refractory eyes. Complete success (6-17 mm Hg with no medications) was achieved in 64.0% of combined eyes, 58.1% of refractory eyes, and 74.8% of stand-alone non-refractory eyes; and qualified success rates (6-17 mm Hg with medications) were 90.7%, 84.7%, and 92.4% of eyes, respectively. At 12 months, 67% of eyes were medication free. Significant risk factors for failure included combined procedures in refractory eyes (hazard ratio [HR] = 3.2; 95% CI = 1.4-7.4), receiving <0.4 mg/mL of MMC (HR = 2.2; 95% CI = 1.6-3.1), refractory eyes (HR = 1.7; 95% CI = 1.2-2.5), combined procedures (HR = 1.6; 95% CI = 1.0-2.5), and each additional baseline medication class (HR = 1.3; 95% CI = 1.1-1.5). Postoperative complications occurred in 31% of eyes, and more often in those receiving ≥0.4 mg/mL MMC (odds ratio [OR] = 2.2, 95% CI 1.2-3.8). Needling occurred in 12% of eyes, with significantly higher frequency in refractory eyes (23%) and combined procedures (13%) compared to stand-alone (7%; P < .001). Revisions and reoperations occurred in 4% and 1.4% of eyes, respectively.

CONCLUSIONS

The 1-year follow-up data from this large and diverse cohort support promising rates of qualified and complete surgical success with decreased medication burden and few postoperative complications and interventions. Combined phacoemulsification, refractory glaucoma, and receiving <0.4mg/mL MMC were associated with reduced surgical success rates.

Effectiveness and Safety of Xen Gel Stent in Glaucoma Surgery: A Systematic Review of the Literature

Although topical medical therapy and selective-laser-trabeculoplasty represent the treatments of choice to reduce intraocular pressure, many patients do not achieve adequate glaucoma control; therefore, they require further options and eventually surgery. Trabeculectomy is still considered the gold standard, but the surgical management of glaucoma has undergone continuous advances in recent years, XEN-gel-stent has been introduced as a safer and less traumatic means of lowering intraocular pressure (IOP) in patients with open-angle glaucoma (OAG). This study aimed to review the effectiveness and safety of clinical data on XEN-stent in OAG patients with a Synthesis-Without-Meta-analysis (SWiM) methodology. A total of 339 studies were identified following a literature search adhering to PRISMA guidelines and, after evaluation, 96 studies are discussed. XEN63 and XEN45 device data were collected both short and long term. In addition, this document has evaluated different aspects related to the XEN implant, including: its role compared to trabeculectomy; the impact of mitomycin-C dose on clinical outcomes; postoperative management of the device; and the identification of potential factors that might predict its clinical outcomes. Finally, current challenges and future perspectives of XEN stent, such as its use in fragile or high myopia patients, were discussed.

New XEN63 Gel Stent Implantation in Open-Angle Glaucoma: A Two-Year Follow-Up Pilot Study

Purpose

The XEN gel stent was developed to reduce the risks of filtration surgery by standardizing the outflow of aqueous humor into the subconjunctival space. Recently, a modified version of the XEN63 gel stent was introduced. The goal of this study was to assess its efficacy and safety.

Methods

This is a prospective, nonrandomized, observational, consecutive case series study at a single tertiary centre. Patients with open-angle glaucoma with above target intraocular pressure (IOP) despite maximal tolerated medication were included. The primary outcome was a change of median IOP. Secondary outcomes included a change in the number of medications, complete success, needling and complication rates. Success was defined as a lowering of IOP > 20% from baseline and IOP ≤ 14 mmHg. Complete success indicated that the target IOP was reached without medications.

Results

Six patients were included. The median IOP decreased from 35.5 mmHg (25.0-40.0 mmHg) at baseline to 11.5 mmHg (4.0-15.0 mmHg, p = 0.03), and median IOP-lowering medication was reduced from 4.0 (3.0-4.0) at baseline to 0 (0-1.0, p = 0.03) after two years. Five patients (83.0%) had a complete success after two years. Two patients (33.0%) required a needling procedure. Three patients (50.0%) required an intervention due to symptomatic hypotony within the first three weeks postoperatively. Hypotony resolved completely or was asymptomatic after three months.

Conclusion

Our study demonstrated a statistically significant reduction in both IOP and number of IOP-lowering medications. Complications were well manageable and had no long-term sequelae.

Complications and post-operative interventions in XEN45 gel stent implantation in the treatment of open angle glaucoma-a systematic review and meta-analysis

BACKGROUND

The XEN45 Gel Stent is a subconjunctival filtering device that has demonstrated promising efficacy. This meta-analysis quantitatively evaluates reported complications and interventions after XEN45 implantation in the treatment of open angle glaucoma (OAG).

METHODS

Pilot, cohort, observational studies, and randomised controlled trials that included at least ten patients undergoing ab interno or externo XEN45 surgery, with or without phacoemulsification were deemed eligible for inclusion. A meta-analysis of proportions with random-effect models was performed using the meta routine in R version 3.2.1. Outcomes included the rate of complications and post-operative interventions.

RESULTS

One hundred and fifty-two studies were identified on initial literature search and 33 were included in final analysis. Numerical hypotony was the most common post-operative complication, involving 20% of patients (95% CI: 10-31%). Post-operative gross hyphema occurred in 14% (95% CI: 7-22%) and transient intra-ocular pressure (IOP) spikes (>30 mmHg) in 13% (95% CI: 4-27%). Stent exposure occurred in 1% (95% CI: 0-2%). Stent migration occurred in 1% (95% CI: 0-3%). XEN45 revision and/or a second XEN45 implantation was performed in 5% of patients (95% CI: 3-7%). Stent relocation was performed in 3% (95% CI: 1-7%). A second glaucoma procedure was performed in 11% (95% CI: 8-15%). 26% underwent one (95% CI: 17-36%), 13% underwent two (95% CI: 5-24%) while 4% underwent three (95% CI: 2-6%) bleb needling procedures. 35% of patients (95% CI: 29-40%) required at least one needling. The average rate of needling per patient was 0.38 (95% CI: 0.20-0.59). However, there is a lack of high-quality data, with 8 of the 33 studies assessed to have a moderate to high risk of bias.

CONCLUSIONS

While literature suggests that XEN45 Gel Stent implantation is safe in the treatment of OAG, the overall current level of evidence is low and further studies are needed. More than a third of patients require at least one post-operative bleb needling procedure.

Efficacy and Safety Outcomes of XEN Implantation and Gonioscopy-assisted Transluminal Trabeculotomy for the Management of Advanced Open-angle Glaucoma

Aim

Minimally invasive glaucoma surgery (MIGS) is not typically used in patients with advanced-stage glaucoma. This study describes the outcomes and complications of patients with advanced open-angle glaucoma (OAG) who underwent XEN implantation with cataract surgery or gonioscopy-assisted transluminal trabeculotomy (GATT) with cataract surgery.

Methods

This retrospective study identified patients who had undergone XEN implantation or GATT for the management of advanced OAG. Outcomes included surgical success, intraocular pressure (IOP) reduction, number of topical IOP-lowering drops, visual field mean deviation (MD), best-corrected visual acuity (BCVA), and complications. Surgical success was defined as an IOP of <14 mm Hg and a 20% reduction at 12 months without topical IOP-lowering drops (complete success) or with topical IOP-lowering drops (qualified success).

Results

Exactly 70 eyes were enrolled in this study, including 35 who had undergone XEN implantation and 35 who had undergone GATT. The overall surgical success rate was 74.3% (26 of 35) for eyes that underwent XEN implantation and 71.4% (25 of 35) for eyes that underwent GATT. Percent IOP reduction from baseline to 12 months postoperatively was 48% in the XEN cohort and 32% in the GATT cohort. Significant reduction in the use of topical IOP-lowering drops was demonstrated for both XEN (3.26 ± 1.15-1.23 ± 1.28) (p < 0.001) and GATT (2.46 ± 1.12-0.43 ± 0.78) (p < 0.001) cohorts at 12 months postoperatively. The only complication reported was transient hyphema, which occurred in three patients from the XEN group and four from the GATT group, and resolved spontaneously.

Conclusions

Both XEN implantation and GATT may be safe and effective management options when treating patients with advanced OAG. However, larger sample sizes are required to make direct statistical comparisons between these techniques.

Clinical significance

In this study, XEN implantation and GATT combined with cataract surgery were each associated with favorable outcomes in patients with advanced OAG.

How to cite this article

Ruparelia S, Sharif M, Shoham-Hazon N. Efficacy and Safety Outcomes of XEN Implantation and Gonioscopy-assisted Transluminal Trabeculotomy for the Management of Advanced Open-angle Glaucoma. J Curr Glaucoma Pract 2023;17(2):63-67.

Delayed Suprachoroidal Hemorrhage After Xen45 Gel Stent

PRCIS

In patients with significant preoperative comorbidities, prolonged activity restrictions beyond 2 weeks after Xen45 surgery may mitigate the risks of delayed SCH.

PURPOSE

To report the first case to date of delayed suprachoroidal hemorrhage (SCH) not associated with hypotony 2 weeks after the placement of the Xen45 gel stent.

CASE SUMMARY

An 84-year-old white man with significant cardiovascular comorbidities underwent uneventful ab externo implantation of a Xen45 gel stent for asymmetric progression of severe primary open angle glaucoma. The patient had a reduction in intraocular pressure by 11 mm Hg on postoperative day 1 and maintained preoperative visual acuity. The intraocular pressure remained stable at 8 mm Hg on multiple postoperative visits until the patient developed a SCH at postoperative week 2 immediately after a light session of physical therapy. The patient was treated medically with topical cycloplegic, steroid, and aqueous suppressants. He maintained preoperative visual acuity throughout the postoperative course and had resolving SCH without the need for surgical intervention.

CONCLUSIONS

This is the first report of a delayed presentation of SCH in the absence of hypotony after ab externo implantation of the Xen45 device. The possibility of this vision-threatening complication should be considered as part of the risk assessment and included in the consent process for the gel stent. In patients with significant preoperative comorbidities, prolonged activity restrictions beyond 2 weeks after Xen45 surgery may mitigate the risks of delayed SCH.

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 XEN gel 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.

XEN® implantation: an effective strategy to stop glaucoma progression despite prior minimally invasive glaucoma surgery

Purpose

The aim of this study was to evaluate whether XEN® implantation is a reasonable and safe method to lower the intraocular pressure (IOP) and amount of medication for adult primary open-angle glaucoma (POAG) over a 3-year period. The influence of the type of anesthesia, previous glaucoma surgery, and postoperative interventions on the outcome were examined.

Methods

In this retrospective study, 96 eyes were included. XEN® implantation was performed as sole procedure under general (n = 86) or local anesthesia (n = 10). IOP and number of glaucoma medication were assessed preoperatively: day 1, week 6, month 3, 6, 12, 24, and 36. Further outcome parameters were Kaplan–Meier success rates, secondary intervention, and complication rates.

Results

IOP decreased from 20.7 ± 5.1 to 12.8 ± 2.5 mmHg at the 36-month follow-up (p < 0.001) and glaucoma therapy was reduced from 3.3 ± 0.8 to 1.2 ± 1.6 (36 months, p < 0.001). Transient postoperative hypotony was documented in 26 eyes (27.1%). General anesthesia resulted in a significant improvement of the survival rate compared to local anesthesia (77% vs. 50%, p = 0.044). Prior iStent inject®, Trabectome®, or SLT laser had no significant impact, such as filter bleb revision. The number of postoperative needlings had a significantly negative influence (p = 0.012).

Conclusion

XEN® implantation effectively and significantly lowers the IOP and number of glaucoma therapy in POAG in the 36-month follow-up with a favorable profile of side effects and few complications. In case of IOP, general anesthesia has a significant positive influence on the survival rate, whereas prior SLT or MIGS does not have significant impact.

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

Purpose

After 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.

Methods

This 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).

Results

7 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.

Conclusion

Ab 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.

Efficacy of the XEN45 Implant in Advanced to End-stage Glaucoma Patients

Purpose

To report the efficacy of the XEN45 implant in advanced to end-stage glaucoma patients, after a 6 months follow-up.

Methods

Retrospective, noncomparative electronic health record audit of patients who had undergone an XEN45 procedure. The main outcome measures were intraocular pressure (IOP) reduction and the number of antihypertensive medications. Secondary outcome measures were the rates of early postoperative complications. Complete and qualified success; failure and hypotony were defined according to the World Glaucoma Association guidelines (Shaarawy TM et al.). Needling rates and short-term complications were assessed and a subgroup analysis was performed.

Results

A total of 39 eyes with advanced to end stage-glaucoma were included. Twenty eyes (51%) had undergone combined cataract surgery and 19 (49%), the XEN45 procedure alone. Mean IOP decreased from 19.67 ± 7.87 mm Hg to 13.18 ± 6.09 mm Hg; the number of medications decreased from a median use of 4 (IQR 2–5) to 0 (IQR 0–1). Complete success was achieved in 24 (61.5%) of the eyes, qualified success in 10 (25.6%), and failure in five (12.82%). Needling was required in 15 (38.46%) of the eyes at 6 months. Choroidal detachment occurred in eight (20.51%) eyes, numerical hypotony (IOP ≤ 5 mm Hg) at day 1 was noted in seven (17.95%) eyes with a full resolution by 2 weeks.

Conclusion

In this short-term follow-up, we have seen that XEN45 is a viable, effective, and safe procedure utilized in advanced to end-stage glaucoma patients. Treating cases of significant hypotony using AC reformation with sulfur hexafluoride (SF6) is a safe and effective procedure.

How to cite this article

Hindi I, Berkowitz E, Waizer I, et al. Efficacy of the XEN45 Implant in Advanced to End-stage Glaucoma Patients. J Curr Glaucoma Pract 2022;16(2):84-90.

3-year Outcomes of XEN Implant Compared to Trabeculectomy, With or Without Phacoemulsification for Open-angle Glaucoma

PRCIS

Trabeculectomy surgery reduces the intraocular pressure (IOP) more than the XEN45 implant over 3 years. There is no difference in the number of antiglaucoma medications between the two procedures. The decision to perform either trabeculectomy or XEN45 implantation must be evaluated on a case-by-case basis, taking into account the high rate of needling of the XEN45.

PURPOSE

The aim of this study was to compare the differences between the efficacy and safety of the XEN45 implant and trabeculectomy (TRAB), either alone or in combination with phacoemulsification (PHACO), in patients with open-angle glaucoma (OAG) at 36 months.

METHODS

A retrospective, single-center and comparative study conducted on OAG patients that underwent XEN45 implantation or trabeculectomy from 2016 to 2018. Patients were divided into four groups: group 1 (XEN45 alone); group 2 (XEN45+PHACO); group 3 (TRAB alone); group 4 (TRAB+PHACO). For statistical purposes, groups 1 and 2 were combined (XEN45 implant), while groups 3 and 4 were also combined (TRAB surgery). Intraocular pressure (IOP), number of antiglaucoma medications (NOAM) and adverse events were evaluated. The main outcome measure was the reduction in IOP at 36 months postoperatively.

RESULTS

One hundred and thirty-four patients (134 eyes; 63 XEN45 and 71 TRAB) were included. The mean (95% CI) IOP reduction at the end of the study follow-up was-6.3 (-11.0 to -1.6 mmHg, P=0.025, XEN45 alone),-8.9 (-11.0 to-6.8 mmHg, P<0.001, TRAB alone),-2.5 (-4.5 to -0.4 mmHg, P=0.019, XEN45+PHACO), and-5.6 (-7.7 to-3.4 mmHg, P<0.001, TRAB±PHACO). The proportion of patients achieving an IOP≥6 and≤16 mmHg without treatment at the end of the 36-month follow-up were 50.8% (32/63) in the XEN45 implant and 49.3% (35/71) in the TRAB surgery group, P=0.863. The mean number of antiglaucoma medications was significantly reduced in all the study groups. The needling rate was 19% in XEN45 versus 5.6% in the TRAB group (P=0.030), and 2.81% and 36.6% of eyes in the TRAB group presented anterior chamber (AC) flattening and hyphema, respectively.

CONCLUSIONS

Trabeculectomy surgery lowered IOP significantly more than XEN45 implant with or without phacoemulsification over 3 years and had a significantly lower need for additional needling surgery. Both procedures reduce the number of antiglaucoma medications to a similar rate. These findings are relevant to the informed consent process and patient decisions for one procedure over the other.

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

Background

Xen 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.

Methods

We 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.

Results

We 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.

Conclusion

Our 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.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12886-022-02502-y.

XEN® 63 gel stent to treat a refractory uveitic glaucoma: A case report

PURPOSE

To describe the effectiveness of the XEN^® 63 gel stent in a refractory uveitic glaucoma after failure of an Ahmed Glaucoma Valve.

CASE DESCRIPTION

We report the case of a 54-year-old man with a history of uveitic glaucoma on his left eye due to Fuchs heterochromic iridocyclitis and neovascular glaucoma after a central retinal vein occlusion. Pre-operative intraocular pressure was 30 mmHg despite a QD (once-daily) dosed bimatoprost 0.3 mg and timolol 5 mg topical medication. At week 1, the eye exam showed an intraocular pressure of 6 mmHg with a well-formed bleb, a very mild hyphema and a localized choroidal detachment. At month 1, intraocular pressure was 14 mmHg with a formed bleb. Both hyphema and choroidal detachments had resolved. After a year, intraocular pressure was 16 mmHg without any medication and the bleb was still well-formed.

CONCLUSION

The XEN^® 63 gel stent provides a good intraocular pressure reduction and can be an efficient alternative for tube and filtration surgery in refractory glaucoma. Its long-term effectiveness needs to be evaluated.

The Outcomes of XEN Gel Stent Implantation: A Systematic Review and Meta-Analysis

Purpose

XEN gel stents are used for the treatment of open-angle glaucoma (OAG), including primary and secondary glaucoma that are uncontrolled by previous medical therapy and cases with previous failed surgery. Our aim was to systematically review of the clinical data of currently published ab-interno XEN gel stents with an emphasis on intraocular pressure (IOP), antiglaucoma medication outcomes, and safety profiles.

Methods

We analyzed all of the publications (MEDLINE, EMBASE, Cochrane Library) on the ab-interno XEN gel stent to evaluate the reduction in IOP and antiglaucoma medications following the procedure. The primary outcomes measured for the meta-analysis were reduction in IOP and anti-glaucoma medications. The secondary outcome were adverse events. For each study, we used a random effects analysis model to calculate the mean difference and 95% confidence intervals for the continuous results (reduction in IOP and antiglaucoma medications) using the inverse variance statistical method.

Results

Five hundred twenty-seven articles were checked and 56 studies were found to be relevant with a total of 4,410 eyes. There was a significant reduction in IOP as well as in the number of medications required in patients treated with ab-interno XEN implant either alone or combined with cataract surgery. This new treatment for various types of glaucoma reduced the IOP by 35% to a final average close to 15 mmHg. This reduction was accompanied by a decrease in the number of antiglaucoma medications in all the studies, approximately 2 classes of medication at the price of more needlings. The overall complete success rate was 21.0–70.8% after 2 years using strict criteria originally designed to record success rate in filtration surgery. The incidence of complications vision-threatening was low at <1%.

Conclusions

XEN gel stent was effective and safe for primary and secondary OAG. Further studies should be performed to investigate the impact of ethnicity on the success and failure rate after XEN implantation.

Conventional glaucoma implants and the new MIGS devices: a comprehensive review of current options and future directions

Glaucoma is a progressive optic neuropathy that is the second leading cause of preventable blindness worldwide, after cataract formation. A rise in the intraocular pressure (IOP) is considered to be a major risk factor for glaucoma and is associated with an abnormal increase of resistance to aqueous humour outflow from the anterior chamber. Glaucoma drainage devices have been developed to provide an alternative pathway through which aqueous humour can effectively exit the anterior chamber, thereby reducing IOP. These devices include the traditional aqueous shunts with tube-plate design, as well as more recent implants, such as the trabeculectomy-modifying EX-PRESS^® implant and the new minimally invasive glaucoma surgery (MIGS) devices. In this review, we will describe each implant in detail, focusing on their efficacy in reducing IOP and safety profile. Additionally, a critical and evidence-based comparison between these implants will be provided. Finally, we will propose potential developments that may help to improve the performance of current devices.

Minimally Invasive Glaucoma Surgery: A Critical Appraisal of the Literature

Micro- or minimally invasive glaucoma surgeries (MIGS) have been the latest addition to the glaucoma surgical treatment paradigm. This term refers not to a single surgery, but rather to a group of distinct procedures and devices that aim to decrease intraocular pressure. Broadly, MIGS can be categorized into surgeries that increase the trabecular outflow [Trabectome, iStent (first and second generations), Hydrus microstent, Kahook Dual Blade and gonioscopy-assisted transluminal trabeculotomy], surgeries that increase suprachoroidal outflow (Cypass microstent and iStent Supra), and conjunctival bleb-forming procedures (Xen gel stent and InnFocus microshunt). Compared to traditional glaucoma surgeries, such as trabeculectomy and glaucoma drainage device implantation (Ahmed, Baerveldt, and Molteno valves), MIGS are touted to have less severe complications and shorter surgical time. MIGS represent an evolving field, and the efficacy and complications of each procedure should be considered independently, giving more importance to high-quality and longer-term studies.

PreserFlo MicroShunt® exposure: a case series

BACKGROUND

PreserFlo® MicroShunt (PM) (also known as InnFocus® MicroShunt) is a subconjunctival stent implanted ab externo via a minimally invasive surgical procedure. The current indication is progressive, mild to moderate, open angle glaucoma uncontrolled on topical medications. According to the literature, adverse events are rare, mild and transient.

CASE PRESENTATION

Two cases of stand-alone PreserFlo MicroShunt® implantation in patients with uncontrolled open-angle glaucoma are reported. Exposure occurred 7 days and 3 months respectively after implantation. These cases shared common features including preexisting blepharitis and the lack of a Tenon's flap. In both cases, removal of the device was required after several attempts at repair.

CONCLUSIONS

PreserFlo MicroShunt® exposure is a potentially vision-threatening complication because of the risk of endophthalmitis. Potential risk factors include the absence of a Tenon's flap and pre-existing ocular surface inflammation. Ocular surface inflammation should be detected and treated prior to PM implantation. If a deficiency in Tenon's capsule is noted intraoperatively, close monitoring should be performed because of the higher risk of PM exposure.

A Retrospective Analysis of Safety and Efficacy of XEN 45 Microstent Combined Cataract Surgery in Open-Angle Glaucoma over 24 Months

Objectives:

To evaluate the effect on intraocular pressure (IOP) reduction and safety of ab interno gelatin microstent (XEN 45 Gel Stent; Aquesys, Inc, Aliso Viejo, CA, USA) microincisional glaucoma/cataract surgery in open-angle glaucoma (OAG).

Materials and Methods:

In this retrospective study, 30 eyes of 25 patients with OAG which underwent XEN 45 implantation combined with simultaneous phacoemulsification were clinically evaluated. Clinical outcomes analyzed included IOP, percent of IOP reduction, medication use, complications, best corrected visual acuity, and surgical outcomes at 24-month follow-up.

Results:

After the XEN 45 combined cataract surgery procedure, IOP dropped from 20.37±4.80 mmHg with a mean of 3.07±1.04 medication classes preoperatively to 14.83±1.91 mmHg with a mean of 0.94±1.11 medication classes at 24 months (p=0.001 for both). At 24 months, 55.6% of patients had IOP ≤18 mmHg without medication, 94.4% of patients had IOP ≤18 mmHg with or without medication, and 61.1% of patients reached ≥20% IOP reduction from baseline.

Conclusion:

XEN 45 is an effective minimally invasive surgical treatment for OAG with significant reduction in IOP and glaucoma medications and minimal complications in long-term follow-up.

A Comparison of Clinical Outcomes After XEN Gel Stent and EX-PRESS Glaucoma Drainage Device Implantation

PRECIS

Although the XEN stent offers a lower risk of hypotony and choroidal effusions with fewer clinic visits postoperatively, its surgical success rate was inferior to the EX-PRESS shunt.

PURPOSE

To compare the clinical efficacy and safety outcomes of the XEN stent and EX-PRESS glaucoma drainage device in glaucomatous eyes.

MATERIALS AND METHODS

One hundred eyes from 88 patients underwent ab interno XEN stent or EX-PRESS shunt implantation (52 XEN and 48 EX-PRESS) for uncontrolled glaucoma at the University of Colorado Eye Center. The primary outcome was surgical success defined as intraocular pressure (IOP) ≥6 and ≤18 mm Hg, without reoperation for uncontrolled glaucoma, loss of light perception, or use of glaucoma medications (complete success). Secondary outcomes were the same requirements allowing for medications (qualified success), mean IOP, medication use, adverse events, and number of postoperative clinic visits in the first 3 months.

RESULTS

Baseline characteristics including glaucoma type and severity were similar between groups, with the exception of XEN patients having fewer men (17% vs. 46%), older patients (median age, 78 vs. 68), and a higher percentage of white patients (89% vs. 69%). Adjusted hazard ratio of failure of XEN relative to EX-PRESS was 3.94 (95% confidence interval, 1.73-9.00, P=0.001) for complete success and 1.61 (95% confidence interval, 0.40-6.38, P=0.501) for qualified success. There were significantly fewer postoperative clinic visits during the first 3 months in the XEN group (5.3 vs. 9.1 visits, P<0.001). The incidence of serous choroidal effusions and hypotony was significantly less after XEN compared with EX-PRESS (1 vs. 9, P=0.02 and 15 vs. 25, P=0.023, respectively). Three XEN stents (5.8%) required removal.

CONCLUSIONS

In this population, although the XEN stent offers a better safety profile and fewer postoperative clinic visits, complete surgical success was inferior to the EX-PRESS shunt.

Combined and stand-alone XEN 45 gel stent implantation: 3-year outcomes and success predictors

PURPOSE

To evaluate the 3-year treatment outcomes of XEN 45 gel stent in open-angle glaucoma patients.

METHODS

In this prospective, single-centre interventional study, consecutive eyes with uncontrolled intraocular pressure (IOP) or signs of disease progression despite medical treatment underwent XEN implantation either alone or combined with phacoemulsification (Phaco + XEN).

MAIN OUTCOME MEASURES

Surgical success was defined as 'complete' when 36-month unmedicated IOP was ≤15 mmHg with a relative IOP reduction ≥ 20% from medicated baseline, while the definition of qualified success allowed no more medications than at baseline. Other definitions of success with different IOP thresholds were also analysed. Secondary outcomes included mean IOP reduction, changes in ocular hypotensive medications and rates of reoperations.

RESULTS

Out of 149 eyes initially included, 92 eyes (61.7%) of 68 patients had complete 3-year data (XEN: n = 26; Phaco + XEN: n = 66) after 38.2% were lost to follow-up. Mean age was 76.3 ± 9.1 years, and 66.2% were female. Mean medicated IOP decreased from 20.8 ± 7.4 mmHg (21.0 ± 7.4 [XEN] vs. 20.0 ± 6.9 mmHg [Phaco + XEN]) at baseline to 13.1 ± 3.4 mmHg (12.9 ± 2.9 [XEN] vs. 12.9 ± 3.4 [Phaco + XEN]) at 3 years (-37.0%; p < 0.001). Medications decreased from 1.9 ± 1.3 (2.4 ± 1.5 [XEN] vs. 1.9 ± 1.2 [Phaco + XEN]) to 0.4 ± 0.9 (0.3 ± 0.8 [XEN] vs. 0.5 ± 0.9 [Phaco + XEN]) (-78.9%; p < 0.001). Complete success and qualified success were achieved in 29.0% and 31.0% of eyes, respectively. Needling revision was performed in 51 eyes (55.4%), and 26.1% underwent reoperations. Risk factors for surgical failure included male gender (odds ratio [OR]:3.6; p = 0.03), diagnosis of POAG (OR: 4.5; p < 0.01) and undergoing needling revision (OR: 4.6; p < 0.01). While the type of procedure had no effect on the outcomes of PEXG, POAG eyes undergoing combined surgery had significantly higher rates of failure (OR: 7.29; p = 0.023). Most patients stable at 12-month remained so through to 3 years.

CONCLUSIONS

At 3 years, XEN gel stent implantation achieved clinically significant IOP and medication reduction despite relatively high rates of needling and reoperations. Identifying patients at risk preoperatively may help optimize surgical outcomes.

XEN® Gel Stent compared to PRESERFLO™ MicroShunt implantation for primary open-angle glaucoma: two-year results

Purpose

To evaluate the long‐term efficacy and safety of two minimally invasive glaucoma surgery implants with a subconjunctival drainage approach: the XEN45 Gel Stent^® (Xen) implant and the PRESERFLO™ MicroShunt (MicroShunt).

Methods

Retrospective comparative case series of primary open‐angle glaucoma (POAG) patients with at least 6 months of follow‐up after a MicroShunt or Xen implantation augmented with mitomycin C.

Results

Forty‐one eyes of 31 patients underwent Xen implantation, and 41 eyes of 33 patients, MicroShunt implantation. Baseline characteristics were similar, except for more combined surgeries with phacoemulsification in the Xen group (37% vs. 2%). Mean baseline IOP ± standard deviation dropped from 19.2 ± 4.4 to 13.8 ± 3.8 mmHg (n = 26) in the Xen group and from 20.1 ± 5.0 to 12.1 ± 3.5 (n = 14) in the MicroShunt group at 24 months of follow‐up (p = 0.19, t‐test). The number of IOP‐lowering medications dropped from 2.5 ± 1.4 to 0.9 ± 1.2 in the Xen group and from 2.3 ± 1.5 to 0.7 ± 1.1 in the MicroShunt group. The probability of qualified success was 73% and 79% at 24 months of follow‐up for the Xen and MicroShunt groups, respectively. Postoperative complications were usually mild and self‐limiting. The number of bleb needling and secondary glaucoma surgery procedures was similar in both groups; however, in the Xen group more additional MicroPulse^® transscleral cyclophotocoagulation procedures were performed.

Conclusion

Xen Gel Stent and PreserFlo MicroShunt implantations achieved comparable results in POAG eyes in terms of IOP‐lowering and surgical success, with a similar high safety profile.

Standalone XEN45 Gel Stent implantation versus combined XEN45-phacoemulsification in the treatment of open angle glaucoma-a systematic review and meta-analysis

PURPOSE

The XEN45 Gel Stent is currently the only FDA-approved sub-conjunctival minimally invasive glaucoma surgery (MIGS) procedure. It has been used worldwide either as a standalone implantation procedure or in combination with phacoemulsification surgery. Concomitant phacoemulsification is understood to influence outcomes of traditional subconjunctival filtering surgery. However, the comparative efficacy between standalone XEN45 Gel Sent implantation ("Standalone XEN45") and combined XEN-phacoemulsification surgery ("XEN45-Phaco") remains unclear. This study aims to appraise current literature to compare the efficacy of Standalone XEN45 and XEN45-Phaco in open-angle glaucoma.

METHODS

A comprehensive search of PubMed, CINAHL, CENTRAL databases was performed with the terms "Xen surgery" followed by selective vetting. Pilot, cohort, observational studies and randomised controlled trials that included at least 10 patients undergoing either Standalone XEN45 or XEN45-Phaco surgeries for the treatment of open-angle glaucoma were deemed eligible for inclusion after independent assessment by 2 authors. The search workflow was reported according to the PRISMA guidelines. Data was pooled using random-effects model. A meta-analysis of continuous outcome and proportions was performed using the meta routine in R v3.2.1.

RESULTS

Ten studies were included. There was a statistically significant difference in IOP reduction favouring Standalone XEN45 at post-operative day 1, week 1, months 1, 3 and 6. There was a statistically significant difference in decrease in IOP-lowering medications favouring Standalone XEN45 at post-operative week 1 and month 1.

CONCLUSION

Standalone XEN45 has superior IOP-lowering outcomes compared to XEN45-Phaco in the early post-operative period, up to 6 months after surgery.

XEN45 Gel Stent implantation in eyes with primary open angle glaucoma: A study from a single hospital in Taiwan

BACKGROUND

To evaluate the effectiveness and safety of the XEN45 Gel Stent in East Asian patients with primary open angle glaucoma (POAG).

METHODS

We retrospectively reviewed 37 medically uncontrolled POAG patients who received XEN45 Gel Stent. The primary outcomes were reduction in intraocular pressure (IOP) and in the number of glaucoma medications 12 months after surgery. The secondary outcomes were requirement for intervention and further glaucoma surgery. The adverse intraoperative and postoperative events were investigated.

RESULTS

At the 12-month postoperative follow-up, the mean IOP was significantly reduced from the preoperative value of 21.7 ± 7.7 mmHg to 15.0 ± 2.0 mmHg (p = 0.001). The mean number of glaucoma medications decreased from 3.4 ± 0.9 to 1.3 ± 1.5 (p < 0.001). Seventeen patients (45.9%) required postoperative interventions. Four patients (10.8%) received additional glaucoma surgery. Postoperative IOP at month 1 was significantly associated with outcomes at the 12-month follow-up and the need for subsequent intervention and additional glaucoma surgery.

CONCLUSION

The XEN45 Gel Stent effectively reduced the IOP values and number of glaucoma medications in East Asian patients with POAG. No major complications were observed, but almost half of the eyes in the study required intervention for wound healing modification. Postoperative IOP at month 1 was a predictor of surgical success at 12 months after surgery.

XEN gel implant with or without phacoemulsification for glaucoma: a systematic review and meta-analysis

Background

XEN gel implant is an alternative method of treating glaucoma by connecting the anterior chamber and the subconjunctival space. The efficacy of the XEN gel implant and whether to combine with phacoemulsification is what most concerned. This review aims to test the efficacy and safety of the XEN gel implant compared with trabeculectomy and to test the efficacy between XEN combined with phacoemulsification and XEN alone.

Methods

The PubMed, EMBASE, the Cochrane Library, and ClinicalTrials.gov were searched through July 8, 2020. Studies comparing XEN and trabeculectomy or comparing XEN + phacoemulsification and XEN alone were included. The standard mean differences (SMD) were calculated to analyze the lowered intraocular pressure (IOP) and the number of anti-glaucoma medications. All data were measured from baseline to endpoint. The I2 statistic quantified heterogeneity ranged from 0% to 100%, and a random effects model was used in this meta-analysis. Review Manager 5.3 performed all analyses. The t-test calculated all P values, and P values were regarded as statistically significant at P<0.05. The methodological index for non-randomized studies was used to find and test bias in the literature.

Results

Twelve studies with 1,602 eyes were included. Five studies compared the XEN gel implant with trabeculectomy. Eight compared XEN + phacoemulsification with XEN alone. There was no significant correlation between XEN and trabeculectomy groups in lowering IOP (SMD 0.30, 95% CI, 0.00 to 0.60, I²=60%) and reduced the number of IOP lowering drugs (SMD 0.01, 95% CI, –0.16 to 0.17, I²=0%). There was a significant difference between XEN + phacoemulsification and XEN alone in lowering IOP (1,034 eyes, SMD 0.22, 95% CI, 0.05 to 0.40, I²=38%) and reducing the number of medications (729 eyes, SMD 0.20, 95% CI, –0.06 to 0.46, I²=62%).

Conclusions

XEN gel implant, although not effective as trabeculectomy, is a safe operation for open-angle and some other types of glaucoma. Meanwhile, XEN alone is more effective than XEN combined with phacoemulsification within 1 week after operations. After three months, the two groups are similar in lowering IOP. More extensive, better-designed, strictly blinded, multicenter randomized clinical trials are needed to confirm our findings.

Efficacy and safety of XEN 45 gel stent alone or in combination with phacoemulsification in advanced open angle glaucoma patients: 1-year retrospective study

AIM

To assess the effectiveness of the XEN 45 gel stent, either alone or combined with cataract surgery, in advanced stage open angle glaucoma (OAG) patients.

METHODS

Retrospective and single-center study conducted on consecutive OAG patients who underwent a XEN 45 gel stent implantation surgery, between July 2017 and September 2018. The primary efficacy end-point was the mean intraocular pressure (IOP) reduction at the end of the follow-up period. Success was defined as an IOP reduction of at least 20% and an IOP value ≤18 mm Hg without (complete) or with (qualified) hypotensive medication.

RESULTS

Seventy-four patients (80 eyes) were included in the study. In the overall study sample, XEN implant significantly reduced IOP from 21.0 (19.8 to 22.1) mm Hg at baseline to 9.3 (8.2 to 10.4), 10.7 (9.6 to 11.9), 13.4 (12.2 to 14.7), 14.5 (13.6 to 15.4), 14.7 (13.8 to 15.6), and 14.7 (13.9 to 15.4) mm Hg at 1d, 1wk, 1, 3, 6, and 12mo of follow-up, respectively (P<0.0001 each). In the overall study population, at the end of the study the mean IOP reduction was 27.4% (23.3% to 31.5%). Adjusted IOP reduction was similar in XEN and XEN+phacoemulsification groups [30.0 (23.4 to 36.4) mm Hg vs 24.8 (18.4 to 31.2) mm Hg, respectively, P=0.2939]. At the last follow-up visit, 52 (65.0%) eyes were considered success, 29 (36.3%) eyes as complete success and 23 (28.7%) as qualified success. Mean number of hypotensive medications was significantly reduced from 2.8 (2.7 to 3.0) at baseline to 1.1 (0.8 to 1.3), P<0.0001. Kaplan-Meier survival analysis did not find any difference in the success rate between XEN and XEN+PHACO, mean hazard ratio 0.56, 95%CI 0.26 to 1.23; P=0.1469. Needling was performed in 7 (8.8%) eyes at months 1 (n=3); 3 (n=2); 4 (n=1) and 11 (n=1). Eleven (13.8%) eyes presented adverse events.

CONCLUSION

XEN implant, either alone or in combination with phacoemulsification, significantly reduced the IOP and the number of hypotensive medications in patients with OAG in advanced stage.

Minimally Invasive Glaucoma Surgery: Where Is the Evidence?

PURPOSE

The last decade has witnessed an unprecedented growth in glaucoma treatment options through the introduction of minimally invasive glaucoma surgeries (MIGS). The aim of the present review is to provide an understanding of the currently available MIGS and to examine what data are currently available to guide treatment choice.

DESIGN

Meta-analysis and systematic review of randomized and non-randomized control trials.

METHODS

Out of 2567 articles identified, a total of 77 articles were retained for analysis, including 28 comparative studies and 12 randomized control trials. Overall, 7570 eyes were included. When data permitted, the weighted mean difference in intraocular pressure reduction was calculated for comparison purposes.

RESULTS

Weighted mean intraocular pressure reductions from all analyzed studies were: 15.3% (iStent), 29.1% (iStent inject), 36.2% (ab interno canaloplasty), 34.4% (Hydrus), 36.5% (gonioscopically-assisted transluminal trabeculotomy), 24.0% (trabectome), 25.1% (Kahook dual blade), 30.2% (Cypass), 38.8% (XEN), and 50.0% (Preserflo).

CONCLUSIONS

One of the advantages of the heterogenous range of available MIGS options is the chance to tailor therapy in an individualized manner. However, high-quality data are required to make this choice more than an educated guess. Overall, this review confirms the efficiency of assessed MIGS compared with standalone phacoemulsification, but it highlights that only few studies compare different MIGS techniques and even fewer assess MIGS against criterion standard treatments. Current evidence, while non-negligible, is mostly limited to heterogenous nonrandomized studies and uncontrolled retrospective comparisons, with few quality randomized control trials. We suggest that future research should be comparative and include relevant comparators, standardized to report key outcome features, long-term to assess sustainability and late complications, and ideally randomized.

Real-World Retrospective Consecutive Study of Ab Interno XEN 45 Gel Stent Implant with Mitomycin C in Black and Afro-Latino Patients with Glaucoma: 40% Required Secondary Glaucoma Surgery at 1 Year

PURPOSE:

The aim of this study was to determine the postoperative course after the ab interno XEN45 Gel Stent implantation in Black and Afro-Latino, patients with glaucoma.

METHODS:

This was a single-center, retrospective study. All patients with glaucoma who underwent ab interno XEN implantation were included in the study. All of the patients were Black and Afro-Latino making up the demographics of the local community. Investigated parameters were intraocular pressure (IOP), the number of medications, visual acuity, IOP-follow-up, intraoperative and postoperative complications, and additionally performed surgeries.

RESULTS:

Of 20 eyes that had undergone the procedure with 1-year follow-up, eight failed before 12 months requiring additional glaucoma surgery. Of the 12 that were successful at 1 year, 9 (75%) eyes underwent XEN + cataract surgery and 3 (25%) had XEN surgery alone. Of the eyes that completed 12-month follow-up, the mean medicated IOP was 15.3 ± 6.2 mmHg at baseline, and 12.9 ± 4.5 mmHg at 12 months, a 16% IOP reduction. Mean medications dropped from 3.58 ± 0.7 preoperatively to 1.75 ± 1.5 at 12 months.

CONCLUSIONS:

The ab interno XEN gel implant as a standalone procedure or combined with cataract surgery demonstrated a safe and sustained IOP reduction for only 60% of patients after 12 months. In Black and Afro-Latino patients receiving the ab interno XEN implant, 40% of patients needed additional surgery within 12 months.