XEN® Gel Stent for management of chronic open angle glaucoma: A review of the literature

[Glaucoma surgeries: Long-term results - A review]

The surgical treatment of glaucoma has been and is still based on filtering surgeries, commonly used for about half a century. The safety and efficacy of these techniques have been well described, as it has also been done for cyclophotocoagulation and valves or tubes, indicated in France mostly for refractory glaucoma. Minimally invasive glaucoma surgeries have emerged in recent decades, increasing the number of therapeutic options, and allowing treatment decisions to be as patient-centered as possible. Most of these techniques have now been studied for more than five years. Since glaucoma is a chronic, progressive optic neuropathy, the sustainability of each surgery's results is essential. The amount of available data concerning long-term efficacy and safety of glaucoma surgeries is increasing, so we have decided to describe it through this review of the literature.

One year efficacy and safety of inferior implantation of Xen 45® Gel Stent in refractory glaucoma

PURPOSE

The goal of this study was to assess the efficacy and safety of inferior implantation of the Xen Gel 45® Stent in a cohort of refractory glaucoma patients who had undergone multiple failed procedures and lacked healthy superior conjunctiva.

PATIENTS AND METHODS

We retrospectively included individuals with refractory glaucoma who underwent implantation of a Xen 45® in the inferior quadrants of the conjunctiva. At the 12-month mark, two success criteria were assessed: "Complete" success, defined as an intraocular pressure (IOP)≤21mmHg with a≥20% reduction in IOP without additional IOP-lowering medications, the absence of a requirement for additional filtering surgery, and the absence of chronic hypotony; and "Qualified" success, which consisted of patients meeting the same criteria but requiring glaucoma medications postoperatively. Safety was also monitored throughout the 12-month follow-up.

RESULTS

A total of 35 patients who underwent inferior Xen implantation were assessed. After 12months, 20 patients (57.1%) achieved qualified success, with twelve patients (34.3%) attaining complete success. Excluding five patients who underwent additional filtering surgery during follow-up, the mean IOP decreased significantly from 30.73±9.7mmHg to 16.49±7.9mmHg, representing a mean decrease of 14.24±12.13mmHg (46.5%; P<0.0001). The mean number of medications at 12months decreased from 3.43±1.6 to 1.53±1.52 (-55.4%; P<0.0001). The mean number of needlings was 1.29±1.2. Implant exposure was observed in two patients during the first postoperative month.

CONCLUSIONS

Inferior placement of Xen appears to be a viable treatment option for patients with refractory glaucoma and a history of multiple failed glaucoma procedures. It demonstrates both significant efficacy and acceptable safety.

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

PURPOSE

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

METHODS

We retrospectively reviewed 6 patients with refractory glaucoma, defined as persistently high IOP (> 21 mmHg) despite taking at least 3 IOP-lowering medications subsequent to undergoing a glaucoma drainage device (GDD) with or without a second GDD or cilioablative procedure. Eyes with previous failed GDD underwent subconjunctival 0.3 cc (0.4 mg/ml) mitomycin C, tenonectomy, and placement of an ab- externo XEN stent. The outcome measures included change in IOP and the number of glaucoma medications. Success was defined as patients achieving an IOP ≤ 18 mmHg with a percentage reduction of 25% or 15 mmHg and 40% mean IOP reduction from baseline while taking the same number or fewer medications.

RESULTS

All six eyes with age of 77.6 ± 7.82 years who underwent XEN implantation following previous GDD surgery had primary open-angle glaucoma. The IOP decreased significantly from 32.33 ± 5.99 to 12.67 ± 3.27 mmHg (p < 0.001) with a follow-up of 13.9 ± 2 (11.7-16.7) months. Visual acuity and visual field remained stable after XEN placement. Compared to the baseline number of medications of 4.2 ± 0.8, all medication was discontinued except in one eye on two drops at the end of the follow-up. The overall surgical success rate was 100%. No complications, needling, or additional procedures were required.

CONCLUSION

This study described successful implantation of the XEN stent following failed GDD. XEN Gel stent implantation associated with mitomycin C and tenonectomy can be considered a viable surgical option for patients with a history of previously failed tube shunt requiring further IOP lowering.

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

Aim

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

Methods

A systematic review of literature was conducted using Medline (via PubMed), EMBASE, the Cochrane Library databases, and China National Knowledge Infrastructure, from their inception to February 1, 2024.

Results

A total of 48 studies published between 2017 and 2024 were identified and included in the systematic review, including 16 original studies (retrospective or prospective clinical studies), 28 case reports, and 4 case series, which followed patients for up to 5 years. Early postoperative complications of XEN gel stent implantation include hypotony maculopathy (1.9-4.6%), occlusion (3.9-8.8%), suprachoroidal hemorrhage (SCH), choroidal detachment (0-15%), conjunctival erosion, and exposure of the XEN gel stent (1.1-2.3%), wound and bleb leaks (2.1%) and malignant glaucoma (MG) (2.2%). Mid-postoperative complications of XEN gel stent implantation included migration of XEN (1.5%), ptosis (1.2%), endophthalmitis (0.4-3%), macular edema (1.5-4.3%), hypertrophic bleb (8.8%) and subconjunctival XEN gel stent fragmentation (reported in 2 cases). Late postoperative complications reported in cases included spontaneous dislocation and intraocular degradation.

Conclusion

XEN gel stent implantation is a minimally invasive glaucoma surgery (MIGS) procedure for glaucoma, known for its potential to minimize tissue damage and reduce surgical duration. However, it is crucial to note that despite these advantages, there remains a risk of severe complications, including endophthalmitis, SCH, and MG. Therefore, postoperative follow-up and early recognition of severe complications are essential for surgical management.

Anterior Segment Optical Coherence Tomography for Cases of High Intraocular Pressure Following XEN Implant for Glaucoma

PRCIS

This study showed that the XEN patency should be verified by OCT imaging in cases of encapsulated blebs. Although fibrosis plays the principal role, humor aqueous flow reduction could affect the "spacer" effect that inhibits the fibroblast attachments.

PURPOSE

To evaluate the application of the anterior segment optical coherence tomography (AS-OCT) imaging in studying the relationship between a low flow rate through the XEN63 and the development of a cystic bleb.

METHODS

Retrospective case series of 3 eyes presenting a cystic bleb after an XEN63 implantation for uncontrolled intraocular pressure (IOP). Demographic and clinical data were obtained from medical records. The imaging findings, complications, and managements following the surgery were evaluated.

RESULTS

Three patients, with an average age of 67.3 years, initially showed a patent stent lumen and a functional bleb after surgery. The IOP of all eyes increased on average at 28.3 days from the surgery, with a mean value of 39.66 mm Hg. The slit lamp examination showed a cystic bleb. The AS-OCT imaging confirmed the previous finding and revealed either a partial or total occlusion of the stent internal ostium. A Nd:YAG laser, in proximity to the ostium, was performed to resolve the obstruction. Although the AS-OCT imaging showed the device patency and the IOP immediately decreased, the latter became elevated again. Consequently, in all the cases, a further needling procedure was needed to achieve an adequate IOP reduction. Six months after the two-step procedure, the IOP averaged 13.33 mm Hg, the XEN63 lumens appeared cleared, and the blebs showed a functional morphology. No adverse events were observed.

CONCLUSION

The development of a cystic bleb may result from an altered balance between the flow rate through the XEN63 and the fibrosis development in the postoperative healing process. A proper follow-up based on slit lamp biomicroscopy, IOP measurement, and AS-OCT imaging is advisable to estimate and manage a cystic bleb following XEN63 implantation.

Minimally invasive micro sclerostomy (MIMS) procedure in the treatment of open-angle glaucoma

BACKGROUND

To evaluate the safety and efficacy of the Minimally Invasive Micro Sclerotomy (MIMS) procedure in the management of uncontrolled open-angle glaucoma.

METHODS

A prospective, open-label, single-arm clinical evaluation with intra-subject comparisons performed at the Ophthalmologic Center after S.V. Malayan, Yerevan, Armenia. Included were adults with primary open-angle glaucoma (OAG) (N = 114) or exfoliative glaucoma (N = 6) who were uncontrolled (IOP > 21) on tolerated topical medication. Mild (N = 7), moderate (N = 66) and severe (n = 47) cases were prospectively included without preselection. Following subconjunctival Mitomycin C, an ab-interno MIMS procedure was performed alone (N = 100) or combined with phacoemulsification (N = 20). Patients were followed for 52 weeks. Procedure-related complications and adverse events were recorded. Success criteria were defined as -5 < IOP ≤ 21mmHg OR a reduction in IOP of ≥ 20% from baseline with (qualified success) or without (complete success) hypotensive medications.

RESULTS

Mean patient age was 69 ± 10.1 years. The mean duration of the procedure was 2:01 ± 0:41 min:sec. Scleral drainage channels were achieved in all cases. No device malfunctions, intraoperative complications, or serious adverse events were reported. Iris plugging of the sclerostomy site and early spikes in IOP were the most common adverse events. The only reason for failure was final IOP > 21 mmHg on tolerated medication. At 52 weeks (n = 93), mean IOP decreased by 38% from baseline (P < 0.001), from 27.9 ± 3.7 to 17.5 ± 5.3 mmHg, a difference of 10.5 mmHg (95% CI: -11.7, -9.3). One-year qualified success was documented in 82.1% (95% CI: 72.9%,89.2%) of the patients and complete success, in 70.5% (60.3-79.4%). 60% (95 CI:49.4%,69.9%) of the patients achieved maximum IOP level of 14 mmHg or at least 30% reduction in IOP.

CONCLUSIONS

MIMS procedure is a relatively simple, short and safe minimally invasive bleb-forming procedure. Its efficacy, as found in this short-term evaluation, lends it suitable for mild and moderate uncontrolled open-angle glaucoma patients.

TRIAL REGISTRATION

ClinicalTrials.gov ID: NCT04503590 2019-05-29.

Four-Year Outcome of XEN 45 Gel Stent Implantation in a Swedish Population

Purpose

To report the long-time success rate of XEN 45 gel stent implantation in a Scandinavian population.

Patients and Methods

This was a retrospective single-center analysis of all patients undergoing XEN 45 stent surgery between December 2015 and May 2017. The main outcome was success rate according to several definitions of success. Subgroup analysis was performed. Secondary outcomes were change in intraocular pressure (IOP) and number of IOP-lowering agents. Need for secondary glaucoma surgery, needling rate and complications were recorded.

Results

A total of 103 eyes could be evaluated after four years. Mean age was 70.6 years. Primary open-angle glaucoma (POAG) accounted for 46.6% and exfoliative glaucoma (PEXG) for 39.8%. Mean IOP dropped from 24.0 to 15.9 mmHg (p<0.001) and IOP-lowering agents from 3.5 to 1.5 (p<0.001). The success rate with individual target pressures after four years was 43.7%. Secondary glaucoma surgery was performed in 45 (43.7%) of cases. Combined cases (n=12) were not statistically different to stand-alone procedures (p=0.28). No difference between PEXG and POAG could be detected (p=0.44). During the learning curve, stent misplacement was common and resulted in worse outcome for less experienced surgeons.

Conclusion

The overall success rate of XEN 45 gel stent surgery in the present cohort is relatively low in a long-time follow-up under the given circumstances if all initial patients are included to follow-up. The influence of the surgeon's learning curve is obvious, and improvement in success can be expected when used by experienced and high-volume surgeons. No significant differences were found in PEXG compared to POAG or in XEN surgery combined with cataract surgery compared to stand-alone.

Risk Factors for Hyphema Following Kahook Dual Blade Goniotomy Combined With Phacoemulsification

PRCIS

Hyphema development after Kahook Dual Blade (KDB) excisional goniotomy was significantly associated with postoperative day 1 intraocular pressure (IOP) ≤12 mm Hg, male sex, and narrow iridocorneal angles, but not with continuation of anticoagulation or antiplatelet therapy.

PURPOSE

To identify risk factors of hyphema development after KDB goniotomy combined with phacoemulsification.

METHODS

In all, 202 eyes in 145 patients who received a KDB goniotomy combined with phacoemulsification between February 21, 2017 and February 18, 2020 were evaluated for preoperative factors that were predictive of postoperative hyphema. Hyphema was defined as the development of ≥1 mm layered blood in the anterior chamber. The primary outcome was the association between various preoperative factors and the development of postoperative hyphema. Binomial logistic regression was used to analyze risk factors of hyphema development while controlling for other variables.

RESULTS

Hyphema occurred in 8.4% (17/202) of patients on day 1 after KDB goniotomy combined with phacoemulsification. Male sex ( P =0.008), angle closure glaucoma ( P =0.036), and postoperative day 1 IOP ≤12 mm Hg ( P =0.049) were significantly correlated with hyphema development while controlling for other variables. Preoperative anticoagulation and antiplatelet therapy had no association with hyphema development ( P =0.538).

CONCLUSIONS

Postoperative hyphema was associated with male sex, narrow iridocorneal angles, and a postoperative day 1 IOP lower than typical episcleral venous pressure when controlling for other variables. Preoperative anticoagulation or antiplatelet therapy was not associated with developing postoperative hyphema in this study; however, further investigation is needed before recommendations can be made.

Gelatin implant in the treatment of open-angle glaucoma: Safety and efficacy in real-life conditions

OBJECTIVE

To evaluate the safety and efficacy of the Xen® implant for the treatment of open-angle glaucoma.

MATERIAL AND METHOD

Retrospective study including patients who received the Xen® implant between January 2019 and December 2020 in a university hospital. Demographic and medical data were collected using DxCare® software. The primary endpoint was a 20% reduction in intraocular pressure (IOP) at 12 months according to Société Française du Glaucome (SFG) recommendations. The secondary endpoints were decrease in glaucoma medications and incidence of adverse events.

RESULTS

Fifty-three patients (65 eyes) were included (sex ratio 0.65, age 75.38±7.31 years). IOP decreased by 18.51% from 17.86±4.22mmHg to 14.55±2.66mmHg (P<0.05). The number of glaucoma medications was 2.16±1.01 preoperatively vs 0.49±0.94 postoperatively (P<0.05). Adverse events included 8 malpositionings, 3 of which required reoperation, 1 case of increased IOP resolved by trabeculectomy, 1 case of venous ischemia treated by photocoagulation, 3 choroidal detachments and 3 corneal ulcers. Needling was required for 18 eyes.

CONCLUSION

At 12 months, the IOP was lower than previously reported in the literature (14.55 vs 15.90mmHg, P<0.05), probably due to a lower preoperative IOP. The number of postoperative medications was similar to the literature (0.49 vs 0.40, P=0.51), as was the frequency of needling (27.69% vs 32.00%, P=0.36). The frequency of malpositioning was higher (12.31% vs 7.70%, P<0.05), probably due to the management of complicated patients. The efficacy of Xen® was in line with recommendations. It would be interesting to compare the efficacy of Xen® with trabeculectomy.

[Micro-invasive glaucoma surgery]

Glaucoma is a severe, rapidly progressing disease that in the absence of proper treatment leads to blindness in 20% of patients. According to the World Glaucoma Association, this disease is the most socially significant in modern ophthalmology and requires searching for new and effective methods of treatment. This article presents the results of research and reviews on this issue, considers both conservative therapy and surgical methods of treatment, analyzes in detail modern methods of micro-invasive eye surgery actively used in clinical practice. The article also describes indications for a various types of interventions, as well as the effect achieved by them and the possible complications, and presents the conclusions about the possibility of using these procedures in wide clinical practice.

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.

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

Background

To compare the surgical outcomes and postoperative complications with and without Ologen collagen matrix augmentation during XEN gel stent implantation.

Methods

We 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.

Results

A 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.

Conclusions

All 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.

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.

A comparison of iStent combined with phacoemulsification and endocyclophotocoagulation (ICE2) with the PreserFlo MicroShunt and XEN-45 implants

Background

Minimally invasive glaucoma surgery (MIGS), including minimally invasive bleb surgery (MIBS), is a rapidly evolving area of research and clinical interest in ophthalmology. The growing number of devices has necessitated evaluations to identify subtle differences in outcomes between treatments.

Objectives

To compare clinical effectiveness and safety outcomes of iStent combined with endoscopic cyclophotocoagulation (ICE2) with bleb forming PreserFlo MicroShunt (PMS) and XEN-45 gel implant in a 24-month retrospective review.

Design

A retrospective review of patient records.

Methods

We compared outcomes of 247 patients undergoing one of three glaucoma procedures (ICE2 = 162; PMS = 48; XEN-45 = 37) at a single facility in the United Kingdom. Clinical records were reviewed retrospectively between July 2016 and May 2020. Pairwise comparisons and within group analyses were performed to assess intraocular pressure (IOP), best-corrected LogMAR visual acuity (BCVA), the Humphrey visual fields and antiglaucoma medication outcomes across the three treatment groups.

Results

No statistically significantly differences in IOP between the groups at day 7, 6 months, 12 months and 24 months. PMS had statistically significantly change in IOP between baseline and day 7 compared with ICE2 (p = 0.003). BCVA was statistically significant different at 24 months between the ICE2 compared with PMS group (0.12 versus 0.33 LogMAR; p = 0.002). PMS group achieved the largest decline in medication usage between baseline a 24-month follow-up (2.9 versus 0.9; p < 0.001), with no statistically significant difference in the number of antiglaucoma medications being used between groups at 24 months. Postoperative complications in all three groups were transient and could be resolved with office-based interventions.

Conclusion

Real-world outcomes after 24 months were similar between patients undergoing MIGS and MIBS procedures.

Compatibility and Durability of the Gel Stent Material

INTRODUCTION

The XEN Gel Stent (AbbVie Pharmaceuticals) is a device made from Gelatin; a well-known material in the medical field that is firm enough to hold its shape and soft enough to conform to tissues and reduce the risk of erosion. The Gel Stent creates a permanent outflow connection between the anterior chamber and subconjunctival space.

AREAS COVERED

Validation testing done on the Gel Stent to evaluate biocompatibility and durability of the material as well as real-world experience are included and discussed in this paper.

EXPERT OPINION

Correlating the results of the preclinical testing, study outcomes available in the published literature, and the surgeons' experiences, the device and materials have shown to have an acceptable biocompatibility and durability profile, with a stable, nondegradable, and permanent implant.

XEN-related hypotonous maculopathy from iatrogenic cyclodialysis cleft treated with argon laser gonio-cyclopexy

We present a previously undescribed case of a persistent hypotony maculopathy secondary to an iatrogenic cyclodialysis cleft created during XEN-45 gel stent insertion. We present this case as a further analysis of the Karimi et al case of cyclopexy by the corresponding surgeon. Following right XEN-45 implantation, our patient developed immediate and persistent postoperative hypotony for 4 weeks. Gonioscopy revealed a small cyclodialysis cleft at the 1-2 o'clock position. The cyclodialysis cleft was sealed with direct gonioscopic argon laser cyclopexy. Two months after laser treatment and total of 6 months post XEN-45 insertion, right eye visual acuity returned to 6/4 with intraocular pressure 11 mm Hg without any glaucoma medication. Here, we present details of the non-invasive safe and successful management of hypotony maculopathy secondary to the cleft using Argon laser gonio cyclopexy, with no requirement of return to theatre.

Minimally Invasive Micro Sclerostomy (MIMS) Procedure: A Novel Glaucoma Filtration Procedure

PRCIS

Intermediate-term results suggest that ab interno Minimally Invasive Micro Sclerostomy (MIMS) stent-less subconjunctival filtration procedure is a promising treatment option for patients with open-angle glaucoma (OAG).

PURPOSE

MIMS is a novel ab interno, stent-less, subconjunctival filtration procedure. This study set to investigate the safety, performance, and efficacy of MIMS in OAG patients.

METHODS

Prospective, open-label, single arm clinical trial with intrasubject comparisons. Study participants were adults with OAG who were candidates for a filtration procedure. Patients were operated by a single surgeon (A.A.) in Chennai, India. Following mitomycin-C pretreatment, ab interno MIMS procedure was performed alone or combined with phacoemulsification surgery. Procedure-related complications and adverse events were assessed. Primary outcomes: patients (%) achieving an intraocular pressure (IOP) ≥5 mm Hg and ≤18 mm Hg, and an IOP reduction of >20% as compared with baseline, with or without hypotensive medications, with no need for recurrent surgery.

RESULTS

Twenty-one phacoemulsification-MIMS and 10 standalone MIMS procedures were performed. Mean age was 63.94±6.33 years. Mean duration of MIMS was 1:58±0:25 (min:s). Scleral tunnels were achieved in all cases. No device malfunctions, intraoperative complications, or serious adverse events were reported. Five (16.12%) patients presented with iris clogging 1 to 24 weeks following procedure. Two were treated with laser and 3 required trabeculectomy. Mean IOP change from baseline at 24 weeks was 47.4% (31.2 to 16.4 mm Hg, P<0.0001, n=23). The mean difference was -14.8 mm Hg (95% confidence interval: -17.6, -11.9) with no statistically significant differences between groups. Qualified success was achieved in 21 (84%), 17 (74%), and 13 (93%) after 12, 24, and 52 weeks, respectively. Complete success was achieved in 17 (68%), 13 (57%), and 8 (57%) after 12, 24, and 52 weeks, respectively.

CONCLUSIONS

The interim results suggest that MIMS procedure may be a simple and effective surgical option for early OAG patients requiring target IOP in high teens although iris clogging of incision site is the major concern with this procedure.

Appositional Choroidal Detachment Following XEN45 Gel Stent Requiring Surgical Drainage

An 82-year-old man with severe primary open-angle glaucoma on maximal medical therapy underwent an ab externo closed conjunctival Xen45 device insertion with mitomycin C. The surgery was uncomplicated, with a first postoperative day intraocular pressure of 4 mm Hg and visual acuity of 20/40 OD. Ten days later, the patient presented with an intraocular pressure of 5 mm Hg and a visual acuity of counting fingers at 5 feet. Examination showed Seidel negative bleb, shallow anterior chamber, and large nonappositional choroidal detachments. Medical therapy with steroids and cycloplegia was initiated. One week later, the serous choroidal detachments became appositional, and Xen explantation and surgical drainage of the choroidal detachment was performed. Postoperatively, the vision improved to 20/60. Significant choroidal detachments can occur after XEN45 implantation requiring surgical intervention.

Multicenter case series of standalone XEN implant vs. combination with phacoemulsification in Turkish patients

PURPOSE

To evaluate and compare the efficacy, safety and needling timing and rates of standalone XEN implant vs. combination with phacoemulsification in Turkish patients.

METHODS

Retrospective, multicenter study which included the data of patients, who had open angle glaucoma including primary open angle glaucoma and pseudoexfoliation glaucoma, underwent standalone XEN implantation (XEN alone) and combined surgery with phacoemulsification (XEN + Phaco) between 2016 and 2018.

RESULTS

The study included 26 eyes of 24 patients in XEN alone group and 32 eyes of 30 patients in XEN + Phaco group. The mean intraocular pressure (IOP) was 23.3 ± 6.0 mmHg and 24.4 ± 7.4 mmHg at baseline (p = 0.838), and it reduced to 16.3 ± 3.0 mmHg and 16.4 ± 2.3 mmHg at 12-month follow-up (p = 0.436) in XEN alone and XEN + Phaco groups, respectively (reduction: %30 and %33, P = 0.642). The mean number of medications reduced from 2.9 + 0.7 before surgery to 0.9 + 0.9 on month 12. In XEN alone and XEN + Phaco groups, the needling rates were 42.3% and 31.2% (p = 0.491), and the mean time to needling was 3.7 ± 3.2 months and 4.9 ± 8.0 months (p = 0.696), respectively. Hypotonia (17.2%) and hyphema (10.3%) were the most frequent complications, respectively. In XEN alone and XEN + Phaco groups, partial success was achieved in 73.1% and 71.9% of eyes when defined as IOP < 18 mmHg with any medication, respectively (p = 0.920).

CONCLUSION

The XEN implant provides significant reduction in IOP and number of medications, either standalone or combination with phacoemulsification. Both procedures need intensive postoperative care, requiring needling in approximately one-third of patients.

XEN-Augmented Deep Sclerectomy: Step-by-step Description of a Novel Surgical Technique for the Management of Open-angle Glaucoma

AIM AND BACKGROUND

The present case report describes a novel surgical technique combining XEN gel stent implantation and deep sclerectomy: XEN-augmented deep sclerectomy (XEN-DS).

CASE DESCRIPTION

An active 96-year-old Caucasian woman suffering from pseudoexfoliative glaucoma (PEXG) presented with intraocular pressure (IOP) of 24 mm Hg and a double arcuate visual field defect [mean deviation (MD) -9.6 dB] in her only functional eye despite maximal medical therapy. Considering (1) the magnitude of IOP reduction sought, (2) the risk of complications associated with trabeculectomies and glaucoma drainage devices, and (3) the risk of missed appointments due to the patient's personal and social circumstances, it was decided to tailor the surgical treatment to this patient's specific characteristics combining two existing surgical techniques. Following conjunctival dissection, a superficial scleral flap was lifted 2 mm more posteriorly than in conventional DS, and a XEN gel stent was implanted ab externo through the anterior wall of the deep sclerectomy, into the anterior chamber. A mitomycin C-soaked autologous space maintainer was used. No peri- or postoperative complications were observed. Following XEN-DS, her IOP stabilized between 5 mm Hg and 8 mm Hg through 6 months, and her visual field MD improved to -1.5 dB.

DISCUSSION

The present case report is a proof of concept for this novel surgical technique, confirming that XEN-DS has the potential to achieve substantial and persistent IOP reductions in PEXG with a satisfactory safety profile. Clinical studies are warranted to confirm these results.

HOW TO CITE THIS ARTICLE

Niegowski LJ, Gillmann K, Baumgartner JM. XEN-Augmented Deep Sclerectomy: Step-by-step Description of a Novel Surgical Technique for the Management of Open-angle Glaucoma. J Curr Glaucoma Pract 2021;15(3):144-148.

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.

Multicenter case series of standalone XEN implant vs. combination with phacoemulsification in Turkish patients

PURPOSE

To evaluate and compare the efficacy, safety and needling timing and rates of standalone XEN implant vs. combination with phacoemulsification in Turkish patients.

METHODS

Retrospective, multicenter study which included the data of patients, who had open angle glaucoma including primary open angle glaucoma and pseudoexfoliation glaucoma, underwent standalone XEN implantation (XEN alone) and combined surgery with phacoemulsification (XEN + Phaco) between 2016 and 2018.

RESULTS

The study included 26 eyes of 24 patients in XEN alone group and 32 eyes of 30 patients in XEN + Phaco group. The mean intraocular pressure (IOP) was 23.3 ± 6.0 mmHg and 24.4 ± 7.4 mmHg at baseline (p = 0.838), and it reduced to 16.3 ± 3.0 mmHg and 16.4 ± 2.3 mmHg at 12-month follow-up (p = 0.436) in XEN alone and XEN + Phaco groups, respectively (reduction: %30 and %33, P = 0.642). The mean number of medications reduced from 2.9 + 0.7 before surgery to 0.9 + 0.9 on month 12. In XEN alone and XEN + Phaco groups, the needling rates were 42.3% and 31.2% (p = 0.491), and the mean time to needling was 3.7 ± 3.2 months and 4.9 ± 8.0 months (p = 0.696), respectively. Hypotonia (17.2%) and hyphema (10.3%) were the most frequent complications, respectively. In XEN alone and XEN + Phaco groups, partial success was achieved in 73.1% and 71.9% of eyes when defined as IOP < 18 mmHg with any medication, respectively (p = 0.920).

CONCLUSION

The XEN implant provides significant reduction in IOP and number of medications, either standalone or combination with phacoemulsification. Both procedures need intensive postoperative care, requiring needling in approximately one-third of patients.

[Results of filtering trabeculotomy (FTO) compared to conventional trabeculectomy (TE)-a matched case control study]

Ziel

Ziel dieser Studie war es, die 2‑Jahres-Ergebnisse der filtrierenden Trabekulotomie (FTO) im Vergleich zur konventionellen Trabekulektomie (TE) bei primärem Offenwinkelglaukom, Pseudoexfoliationsglaukom und Pigmentglaukom zu untersuchen.

Patienten und Methoden

Es wurden 30 konsekutive Patienten nach FTO und 87 Patienten nach TE nach intraokularem Druck (IOD) und Alter im Verhältnis 1:3 gematcht. Primärer Endpunkt war das Erreichen des Zieldrucks nach 2 Jahren. Als vollständiger Erfolg wurde ein IOD ohne Medikamente von ≤ 18 mm Hg bei gleichzeitiger IOD-Reduktion um ≥ 30 % definiert, als qualifizierter Erfolg, wenn hierfür zusätzlich Medikamente erforderlich waren. Sekundäre Endpunkte waren mittlere Drucksenkung, resultierende Sehschärfe, Komplikationen und nachfolgende Operationen. Die Operationstechnik der filtrierenden Trabekulotomie ist als Video zu diesem Beitrag abrufbar.

Ergebnisse

Zwei-Jahres-Daten konnten von 27 Patienten aus der FTO-Gruppe und 68 Patienten aus der TE-Gruppe erhoben werden. Die Patienten beider Gruppen wurden vor Beginn der Studie bezüglich Alter und IOD gematcht, waren aber auch bezüglich Sehschärfe, Geschlecht und Medikation nicht unterschiedlich. Der Median des präoperativen IOD unter Therapie betrug in beiden Gruppen 23,0 mm Hg. Nach den oben genannten Kriterien wurde ein qualifizierter 2‑Jahres-Erfolg bei 70,4 % der FTO-Gruppe und bei 77,6 % der TE-Gruppe erzielt (p = 0,60), ein vollständiger 2‑Jahres-Erfolg bei 33,3 % der FTO-Gruppe und bei 56,7 % der TE-Gruppe (p = 0,07). Beide Operationsmethoden senkten den Augeninnendruck nach 24 Monaten signifikant (p < 0,001), und zwar auf 12,8 mm Hg in der FTO-Gruppe und 11,0 mm Hg in der TE-Gruppe. Die Sehschärfe war postoperativ bei beiden Gruppen etwas verringert, unterschied sich jedoch nicht signifikant zwischen beiden Gruppen. Komplikations- und Reoperationsrate waren gering und unterschieden sich nicht zwischen den Gruppen.

Schlussfolgerung

FTO und TE sind nach 2 Jahren weitgehend gleichwertig bezüglich Zieldruck, IOD-Senkung, Sehschärfe und Komplikationen.

Video online

Die Online-Version dieses Beitrags (10.1007/s00347-021-01365-w) enthält ein Video zur Operationstechnik der filtrierenden Trabekulotomie. Beitrag und Video stehen Ihnen auf www.springermedizin.de zur Verfügung. Bitte geben Sie dort den Beitragstitel in die Suche ein, das Zusatzmaterial finden Sie beim Beitrag unter „Ergänzende Inhalte“.

Efficacy of the XEN-Implant in Glaucoma and a Meta-Analysis of the Literature

Background: To assess the efficacy of XEN-implant surgery in patients with glaucoma, and to perform a meta-analysis of previously published results and compare these to our data. Methods: Prospective case-control study, in which all eyes that underwent XEN-implant surgery were included from 2015 onwards. Sub-analyses were performed for eyes that underwent XEN-implant as standalone procedure and as cataract-combined procedure. To compare our results, a systematic review was performed using the Embase, PubMed, Web of Science, and Cochrane database. Meta-analyses were performed by combining data (intraocular pressure (IOP), IOP-lowering medication, and complications) from the retrieved studies. Results: A total of 221 eyes underwent XEN-implant surgery (124 standalone and 97 cataract-combined). The mean ± standard deviation IOP declined from 18.8 ± 6.5 to 13.5 ± 4.3 mmHg at the last follow-up (p < 0.001; 28.9%). Postoperative, no significant differences in IOP or IOP-lowering medication were found between patients with and without combined procedure. Secondary surgeries were performed in 20.8% of eyes, most of them (63.0%) within six months. A meta-analysis of 19 studies retrieved from the systematic review showed a two-years postoperative pooled mean (weighted mean difference) of 14.5 (7.3) mmHg and 1.0 (1.6) for IOP and IOP-lowering medications, respectively (compared to 13.5 (5.3) mmHg and 3.2 (2.4) in the current study). Conclusion: XEN-implant surgery was effective and safe in lowering IOP and the number of IOP-lowering medications. There were no differences between standalone and combined procedures.

Ab-Externo Implantation of XEN Gel Stent for Refractory Steroid-Induced Glaucoma After Lamellar Keratoplasty

The hazy corneal donor-recipient interface after corneal transplant may cause difficulties when implanting the XEN gel stent via ab-interno approach. We aim to describe XEN gel stent implantation via ab-externo approach in refractory steroid-induced glaucoma after corneal lamellar keratoplasty. Under local anaesthesia, the XEN injector needle was inserted 7 mm behind the limbus with the bevel facing up, directly beneath the conjunctiva and advanced to the marked 2.5 mm scleral entry wound. The needle then pierced the sclera until the needle tip was just visible in the anterior chamber (AC). The slider was pushed until the tip of the XEN stent was seen in the AC. The needle was slowly withdrawn while still pushing the slider to complete stent deployment. Subconjunctival Mitomycin C 0.01% (30 µg/0.3 mL) was then injected posterior to the bleb. Three eyes of three patients with steroid-induced glaucoma after lamellar keratoplasty underwent XEN gel stent implantation via ab-externo approach placed at the superotemporal quadrant. Pre-operatively, all patients had uncontrolled IOP between 30-45 mmHg despite maximum medications and selective laser trabeculoplasty. After XEN gel stent implantation, IOP ranged between 10-17 mmHg with one or two topical antiglaucoma at 12 months. Complications include hypotony maculopathy, stent migration and hyphaema, all of which were successfully managed. Corneal graft remained clear at 12 months. XEN gel stent implantation via ab-externo approach is able to achieve good intraocular pressure (IOP) control without compromising cornea graft in patients with steroid-induced glaucoma after lamellar keratoplasty at 12 months.

European study of the efficacy of a cross-linked gel stent for the treatment of glaucoma

PURPOSE

To investigate the efficacy and safety of a cross-linked gel stent (XEN45) with or without cataract surgery in the treatment of glaucoma patients.

SETTING

Five university hospitals.

DESIGN

Prospective multicenter clinical trial.

METHODS

Patients with glaucoma inadequately controlled by treatment or poor compliance or intolerance to topical therapy were included. Patients were divided into those who had an implant only (Solo Group; phakic and pseudophakic patients) and those who had an implant combined with cataract surgery (Combo Group). Differences in mean intraocular pressure (IOP) and number of medications between the baseline preoperative visit and study end (12 months), and the rate of qualified and complete success, were evaluated.

RESULTS

The Solo Group comprised 115 glaucoma patients (43 phakic and 72 pseudophakic) and the Combo Group comprised 56 patients. Compared with baseline, mean IOP (23.9 ± 7.6 to 15.5 ± 3.9) and number of medications (3.0 ± 1.1 to 0.5 ± 1.0) decreased significantly at 12-month follow-up (P < .001 for both). A >20% and >30% reduction in IOP from baseline was achieved by 72.3% and 52.6% of patients, respectively. IOP at 1 week postoperatively was a predictor of success, and the needling rate was inversely correlated with early postoperative IOP. The number of preoperative medications and patient age were not significantly associated with failure.

CONCLUSIONS

Insertion of a cross-linked gel stent alone or combined with phacoemulsification might be effective and safe in the treatment of open-angle glaucoma, with a substantial reduction in IOP and number of medications.

Fouling in ocular devices: implications for drug delivery, bioactive surface immobilization, and biomaterial design

The last 30 years has seen a proliferation of research on protein-resistant biomaterials targeted at designing bio-inert surfaces, which are prerequisite for optimal performance of implantable devices that contact biological fluids and tissues. These efforts have only been able to yield minimal results, and hence, the ideal anti-fouling biomaterial has remained elusive. Some studies have yielded biomaterials with a reduced fouling index among which high molecular weight polyethylene glycols have remained dominant. Interestingly, the field of implantable ocular devices has not experienced an outflow of research in this area, possibly due to the assumption that biomaterials tested in other body fluids can be translated for application in the ocular space. Unfortunately, progression in the molecular understanding of many ocular conditions has brought to the fore the need for treatment options that necessitates the use of anti-fouling biomaterials. From the earliest implanted horsehair and silk seton for glaucoma drainage to the recent mini telescopes for sight recovery, this review provides a concise incursion into the gradual evolution of biomaterials for the design of implantable ocular devices as well as approaches used to overcome the challenges with fouling. The implication of fouling for drug delivery, the design of immune-responsive biomaterials, as well as advanced surface immobilization approaches to support the overall performance of implantable ocular devices are also reviewed.

Outcomes of Gel Stent Implantation for Glaucoma in Patients With Previous Corneal Graft Surgery: A Case Series

PURPOSE

To report a series of 5 cases with successful placement of a minimally invasive glaucoma surgery (MIGS) device for glaucoma refractory to medical management in patients with previous corneal grafts.

METHODS

This is a retrospective analysis of all cases with a Xen45 Gel Stent (Allergan plc, Dublin, Ireland) for ocular hypertension and glaucoma refractory to medical treatment after corneal graft surgery between 2016 and 2019 at the Rothschild Foundation, Paris. We did the imaging studies and studied the intraocular pressure (IOP) and the endothelial cell count preimplantation and postimplantation with a MIGS device.

RESULTS

Five cases were included in this study, demonstrating a well-tolerated, highly effective, and sustained method for controlling the IOP, which was refractory to previous treatment. An average IOP reduction of 70.5% was noted with a needling rate of 20%, and no adverse events were noted except 1 IOP spike day 7 post-op with no long-term effects.

CONCLUSIONS

Glaucoma after graft surgery is a well-known and devastating complication, and as numbers of graft surgery performed increases, so will the incidence of glaucoma. MIGS devices such as the Xen45 Gel Stent (Allergan plc) should become a part of our accepted armory to treat raised IOP refractory to medical treatment without delay.

[Treatment of secondary glaucoma following intravitreal anti-VEGF therapy with the XEN® gel stent and mitomycin C]

BACKGROUND

Recurrent treatment with intravitreal anti-VEGF (vascular endothelial growth factor) administration can in rare cases lead to secondary glaucoma that is difficult to adjust. The goal of this case series was to analyze the treatment results of the XEN® gel stent in combination with mitomycin C.

METHODS

The long-term follow-up over a period of 18 months was evaluated for 3 eyes in 3 patients that underwent treatment with a XEN® gel stent in combination with mitomycin C as a surgical procedure to reduce intraocular pressure.

RESULTS

The eyes had a baseline pressure of 21-31 mm Hg with 3-5 antiglaucoma medications following 15-25 intravitreal injections. In all 3 eyes a pressure drop of almost 50% to 9-14 mm Hg could be achieved after 18 months with complete discontinuation of all local and systemic medications to reduce intraocular pressure in 2 of the 3 eyes. In 1 eye a choroidal detachment occurred for 2 weeks postoperatively. In another eye a surgical revision of conjunctival penetration was carried out. In two eyes needling was necessary due to scarring. In 2 out of 3 eyes, further intravitreal treatment (9 and 13 respectively) was necessary due to the macular disease but no further increase in intraocular pressure occurred.

CONCLUSION

The XEN® gel stent in combination with mitomycin C is a therapeutic option for difficult to adjust secondary glaucoma following intravitreal anti-VEGF therapy. A continuation of intravitreal anti-VEGF therapy did not lead to a recurrent increase of intraocular pressure.

Learning Curve and One-Year Outcome of XEN 45 Gel Stent Implantation in a Swedish Population

Purpose

Evaluation of 1-year-outcome of XEN 45 gel stent surgery in a Swedish cohort with regard to clinical success, complications, and learning curve.

Patients and Methods

This was a retrospective study of glaucoma patients undergoing glaucoma XEN-stent surgery alone or combined with phacoemulsification between December 2015 and May 2017. Intraocular pressure (IOP), number of medical agents, and adverse events were assessed. Clinical success rate was defined as achieving individual target pressure with/without medication.

Results

A total of 113 eyes were included in the final statistics. Mean age was 70.8±11.8 years. Primary open angle glaucoma (POAG) accounted for 46.9% and exfoliative glaucoma (PEXG) for 40.7%. Mean preoperative IOP was 23.8±6.2 mmHg and mean number of agents 3.4. After 1 year, mean IOP was reduced to 16.1±4.7 mmHg and medication to 1.34 substances on average. Failure rate at 1-year follow-up was 34% with no significant difference between POAG and PEXG. There was a trend of higher success rate for combined cases (P=0.116). Stents with malpositioned or curved appearance had significantly worse outcome. The failure rate of the most productive surgeon dropped from 33% to 10% from the first implantations. Temporary hypotony (19.5%) and choroidal detachment (9.7%) were the most common complications. Blockage of the inner stent lumen was common (8.8%), with a high proportion of failure.

Conclusion

XEN-stent surgery is a surgical option in uncontrolled glaucoma in both POAG and PEXG. A XEN-stent can reduce both IOP and the number of antiglaucoma medications needed. The learning curve is significant and stent positioning is crucial for optimal results. Combined XEN-cataract surgery is not inferior to stand-alone procedures. The long-time effectiveness is still to be proven.

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.

Is the Xen® Gel Stent really minimally invasive?

Purpose

To describe a case of severe Streptococcus pneumoniae endophthalmitis in a patient with a cystic, avascular filtering bleb who had been implanted with a Xen® Gel Stent 21 months previously.

Observations

A 64-year-old woman with open-angle glaucoma developed severe endophthalmitis 21 months after Xen® Gel Stent implantation. On presentation, visual acuity was limited to light perception. Examination revealed a 100% hypopyon, blebitis and an exposed stent, along with orbital cellulitis. Immediate explantation of the exposed Xen® was performed, and intravitreal antibiotics were administered. S. pneumoniae was isolated from an anterior chamber paracentesis. Based on the antibiogram, the patient was treated with topical fortified piperacillin, gentamicin and vancomycin along with appropriate systemic antibiotics (intravenous imipenem and oral levofloxacin). After 3 days of antibiotics, she received a daily intravenous bolus of methylprednisolone at a dose of 1 mg/kg/day for three days. Despite these measures, the patient's condition declined, with purulent melting of the globe requiring evisceration.

Conclusionsand Importance

As for other filtering surgeries, blebitis and severe endophthalmitis can occur after Xen® Gel Stent implantation. Patients with thin conjunctiva and/or cystic blebs over the stent should be followed particularly closely.

•

As for other filtering surgeries, blebitis and severe endophthalmitis can occur after Xen® Gel Stent implantation.

•

Erosion of the Xen® Gel Stent through the conjunctiva can lead to severe infection such as blebitis and endophthalmitis.

•

Patients with a cystic bleb should be followed regularly, as they may develop stent exposure and infectious complications.

XEN Gel Stent in Pseudoexfoliative Glaucoma: 2-Year Results of a Prospective Evaluation

PRéCIS:: This study confirms the safety and efficacy of XEN gel stents in the management of pseudoexfoliative glaucoma 2 years after implantation, with success rates similar to primary open-angle glaucoma regardless of the definition of success.

PURPOSE

To compare the long-term safety and efficacy of XEN gel implant surgery (Allergan Inc., Irvine, CA) in patients with pseudoexfoliative glaucoma (PEXG) and primary open-angle glaucoma (POAG).

SETTING

Prospective, interventional study in a tertiary glaucoma center.

METHODS

A total of 110 eyes of 85 patients with POAG (57 eyes) or PEXG (53 eyes) and uncontrolled intraocular pressure (IOP) despite medical treatment underwent combined XEN+cataract surgery or standalone XEN surgery. Mean IOP, mean number of medications, needling rates, and incidence of adverse effects were compared between the 2 groups. Complete surgical success was defined as an unmedicated IOP≤12, 15, 16, or 18 mm Hg at 2 years, both with and without a 20% reduction from baseline.

RESULTS

Combined XEN+cataract surgery was performed in 72% of POAG and 76% of PEXG eyes (P=0.67), the remainder underwent standalone XEN surgery. Patient characteristics were similar between the 2 groups except for older age for the patients with PEXG (78.5±8.5 vs. 71.3±8.7 y; P<0.005). Mean medicated IOP were 19.8±5.8 mm Hg (POAG) versus 19.8±8.2 mm Hg (PEXG) at baseline (P=0.98), and 14.5±3.6 mm Hg (-26.8%) versus 14.2±3.8 mm Hg (-28.3%), respectively, at 2 years (P=0.75). Mean medications concomitantly dropped from 1.9±1.6 (POAG) versus 2.0±1.3 (PEXG) to 0.6±0.9 versus 0.4±0.7, respectively (P=0.29). Using the 16 mm Hg threshold, 51.4% (POAG) versus 57.1% (PEXG) eyes achieved complete success (P=0.70) at 2 years. The difference in success rates between the 2 groups was not statistically significant under any of the definitions of success. By 24 months, needling was performed in 42.8% (POAG) and 43.2% (PEXG) (P=0.64), with an average time to needling of 162.8 and 134.9 days, respectively (P=0.46). The rates of adverse effects were 30.6% (POAG) and 36.4% (PEXG) (P=0.66), and additional glaucoma surgeries were carried out in 14.3% (POAG) versus 15.9% (PEXG) (P=0.89).

CONCLUSIONS

The XEN gel implant as a standalone or combined procedure demonstrated similar efficacy and safety results in PEXG and POAG eyes.

Efficacy and safety at 6 months of the XEN implant for the management of open angle glaucoma

The purpose of this study is to evaluate the efficacy and complications of the XEN implant as a solo procedure or in association with cataract surgery in patients with open angle glaucoma (OAG). All patients who received a XEN implant between June 2017 and June 2018 were included in the study. The primary and secondary outcomes were: the reduction of the intraocular pressure (IOP) at 6 months postoperatively, the decrease of the glaucoma medications 6 months after surgery, the clinical success rate (eyes (%) achieving ≥20% IOP reduction on the same or fewer medications without secondary surgical intervention), the frequency and type of postoperative interventions as well as the complication rate. We included one hundred and seven eyes from 97 patients with primary OAG (79%), or secondary OAG (21%). Seventy-seven patients (72%) received a standalone XEN implantation and 30 (28%) underwent XEN implantation combined with phacoemusification. The IOP decreased from 20.4 mm Hg ± 6.4 preoperatively to 15.4 mm Hg ± 5.3 six months after the surgery, which represented a reduction of 24.5% (P = 1.4.10⁻⁷). It was associated with a lowering of glaucoma medications from 2.8 ± 1.0 preoperatively to 0.6 ± 1.0 six months postoperatively (P = 3.6.10⁻³⁴). The clinical success rate was 67.2% six months after the surgery. The most frequent complications were: IOP spikes >30 mmHg (16.8%), improper position or angled drain (14.0%) and transient minimal hyphema (<1 week) (11.2%). During the follow-up, the needling was required in 34.6% of cases and a total of 10 eyes (9.4%) required a new glaucoma surgery. To conclude XEN implantation appears to be an effective short- and mid-term surgical technique to control IOP in OAG with a low risk of complication. However postoperative maneuvers were frequently required to maintain efficiency.

Second-generation trabecular micro-bypass stent implantation: Retrospective analysis after 12- and 24-month follow-up

BACKGROUND

The study aimed to investigate the 24-month safety and efficacy of implantation of two second-generation iStent inject trabecular micro-bypass stents with concomitant cataract surgery.

METHODS

This consecutive case series included 164 eyes of 109 patients implanted with the iStent inject® device with concomitant cataract surgery. The series was comprised of eyes with primary open-angle glaucoma (n = 84), pseudoexfoliation glaucoma (n = 42), normal-tension glaucoma (n = 18), and ocular hypertension (n = 20). All 164 eyes reached 9-14 months of follow-up ("12-month consistent cohort"), with a subset of 88 eyes reaching 21-26 months of follow-up ("24-month consistent cohort"). Performance outcome measures included intraocular pressure (IOP) and number of glaucoma medications. Safety outcomes included intra- or postoperative complications, the need for secondary procedures and corrected distance visual acuity. Comparisons of change in continuous (e.g., IOP) and categorical (e.g., proportions of eyes on zero medications) measures between baseline and postoperative times were made with the paired t-test and McNemar's chi-squared test, respectively.

RESULTS

At 12 months postoperatively, IOP was reduced by 25.5% (from 20.0 ± 5.5 mmHg to 14.9 ± 2.0 mmHg; p < 0.001); at 24 months postoperatively, IOP was reduced by 26.6% (from 20.3 ± 6.1 mmHg to 14.9 ± 1.9 mmHg; p < 0.001). At 12 months postoperatively, mean number of glaucoma medications was reduced by 85.0% (from 2.0 ± 1.0 to 0.3 ± 0.8 medications; p < 0.001); at 24 months postoperatively, mean number of medications was reduced by 81.0% (from 2.1 ± 1.1 to 0.4 ± 0.8 medications; p < 0.001). After 12 months, 96.3% of eyes had an IOP ≤ 18 mmHg and 58.5% of eyes had an IOP ≤ 15 mmHg, with 81.1% of eyes free of any medication, compared to 1.8% of eyes medication-free in the 12-month cohort at baseline. After 24 months, 98.9% of eyes had an IOP ≤ 18 mmHg and 53.4% of eyes had an IOP ≤ 15 mmHg, with 72.7% free of medication compared to 1.1% of eyes medication-free in the 24-month cohort at baseline. Overall, a high safety profile was observed with no significant postoperative complications.

CONCLUSIONS

The insertion of iStent inject (comprised of two second-generation trabecular micro-bypass stents) with cataract surgery effectively provides a sustained reduction in IOP with a markedly improved medication burden up to 24 months postoperatively.

The treatment of a hypertrophic bleb after XEN gel implantation with the "Drainage Channel with sutures" method: a case report

BACKGROUND

The placement of a XEN gel stent is an ab-interno, minimally invasive glaucoma surgery which provides a subconjunctival drainage pathway and decreases intraocular pressure (IOP).

CASE PRESENTATION

A 75-year-old male patient who had undergone XEN45 gel implantation after phacoemulsification and intraocular lens implantation appealed to the clinic. A filtration bleb was seen that extended through the nasal 180 degrees of the eye which caused ectropion of the lower eyelid. The value of the IOP was 12 mm Hg (mmHg). By the "Drainage Channel with Sutures" method this complication was effectively treated. As with every new method, there is a lack of knowledge about long-term outcomes in terms of effectiveness, technique and complications.

CONCLUSION

The "Drainage Channel with Sutures" method has not been described in the literature yet. By this minimal invasive method, hypertrophic bleb complication of XEN gel implant has been successfully treated.

Real-world Case Series of iStent or iStent inject Trabecular Micro-Bypass Stents Combined with Cataract Surgery

INTRODUCTION

This real-world retrospective case series assessed 12-month effectiveness and safety following implantation of iStent® or iStent inject® trabecular micro-bypass with cataract surgery.

METHODS

Consecutive patients were implanted with either iStent (comprising 1 stent) or iStent inject (comprising 2 stents), together with cataract surgery. Most patients had primary open-angle glaucoma. Effectiveness outcomes through 12 months included intraocular pressure (IOP) and glaucoma medications. Proportional analyses were completed for eyes achieving IOP ≤ 18 mmHg, IOP ≤ 15 mmHg, or IOP reduction ≥ 20% from preoperative; and eyes on 0 medications or ≥ 2 medications. Safety outcomes included adverse events, secondary surgeries, visual acuity, and visual fields.

RESULTS

This analysis included 137 eyes (67 iStent, 70 iStent inject) with cataract and mild to moderate glaucoma or ocular hypertension. Over 73% of eyes in both groups had early disease, and ~ 22% had prior glaucoma surgery. At 12 months postoperatively, mean IOP decreased from 18.4 ± 4.2 mmHg to 14.2 ± 2.5 mmHg in iStent eyes (p < 0.0001), and from 20.4 ± 5.6 mmHg to 14.4 ± 2.1 mmHg in iStent inject eyes (p < 0.0001). The IOP reduction was significantly greater for iStent inject eyes than iStent eyes (6.0 mmHg versus 4.2 mmHg reduction, p = 0.034). Both groups had high proportions of patients achieving the 12-month IOP endpoints, although consistently greater proportions reached these endpoints after iStent inject than iStent: 95.7% versus 92.5% had IOP ≤ 18 mmHg, respectively; 74.3% versus 71.6% had IOP ≤ 15 mmHg, respectively; and 68.6% versus 62.7% had IOP reduction ≥ 20% from baseline, respectively. Mean medication burden at 12 months decreased from 1.8 ± 0.7 to 0.3 ± 0.5 medications in iStent eyes (84.0% reduction, p < 0.0001), and from 1.3 ± 0.9 to 0.1 ± 0.3 medications in iStent inject eyes (94.7% reduction, p < 0.0001). Significantly more iStent inject eyes were medication-free at 12 months than iStent eyes (92.9% versus 76.1% medication-free, respectively; p = 0.0068). Favorable safety included few adverse events, no secondary glaucoma surgeries, and stable visual acuity and visual fields in both groups.

CONCLUSION

Significant and safe IOP and medication reductions were achieved through 12 months after iStent or iStent inject implantation with cataract surgery. iStent inject eyes had greater absolute IOP reduction and more eyes medication-free versus iStent eyes.

FUNDING

Glaukos Corporation.

One-Year Comparative Evaluation of iStent or iStent inject Implantation Combined with Cataract Surgery in a Single Center

INTRODUCTION

This retrospective consecutive case series assessed 12-month effectiveness and safety of iStent® or iStent inject® trabecular micro-bypass implants with cataract surgery in patients with open-angle glaucoma (OAG) in a real-world clinical setting.

METHODS

Effectiveness outcomes consisted of intraocular pressure (IOP) reduction; glaucoma medication reduction; proportions of eyes achieving IOP < 18, < 15, or < 12 mmHg; and proportional analysis of medication usage. Safety outcomes included adverse events, secondary surgeries, and best-corrected visual acuity (BCVA).

RESULTS

This evaluation included 58 eyes with OAG (35 iStent, 23 iStent inject), with 96.6% of eyes having mild or moderate glaucoma. Diagnoses included primary open-angle glaucoma (the majority; 72.4%), pseudoexfoliative glaucoma, and pigmentary glaucoma. Baseline mean IOP and medications were statistically comparable between groups: 16.1 ± 3.6 mmHg on a mean of 1.8 ± 0.8 medications in the iStent group, and 16.2 ± 3.1 mmHg on a mean of 1.7 ± 0.8 medications in the iStent inject group. Twelve months after stent-cataract surgery, mean IOP was significantly lower in the iStent inject group than in the iStent group (13.1 mmHg vs. 15.4 mmHg, respectively; p < 0.001), and the percent reduction in IOP from baseline was significantly greater in iStent inject eyes than in iStent eyes (19.1% vs. 4.3% reduction, respectively; p < 0.001). At 12 months postoperative, significantly greater proportions of iStent inject eyes than iStent eyes achieved IOP < 18 mmHg (100% vs. 80.0% of eyes, respectively; p = 0.035), IOP < 15 mmHg (73.9% vs. 34.3% of eyes, respectively; p = 0.003), and IOP < 12 mmHg (26.1% vs. 0% of eyes, respectively; p = 0.002). Meanwhile, both groups achieved significant medication reductions at 12 months vs. baseline (94.1% reduction in iStent inject eyes, p < 0.0001; and 72.2% reduction in iStent eyes, p < 0.0001), with the percent reduction being significantly greater in iStent inject eyes than in iStent eyes (p = 0.023). At 12 months, mean number of medications was significantly lower in iStent inject eyes than iStent eyes (0.1 vs. 0.5 medications, respectively; p = 0.021), and significantly more iStent inject eyes (95.7%) than iStent eyes (71.4%) were off medications entirely (p = 0.021). A similarly high safety profile was observed in both groups.

CONCLUSION

iStent or iStent inject implantation with cataract surgery resulted in substantial and safe reductions in IOP and medications through 12 months postoperative. Consistent with prior observations, greater efficacy was observed with iStent inject than with iStent.

FUNDING

The Rapid Service Fees were funded by Glaukos Corporation.