Is a Day 1 postoperative review following ab interno Xen gel stent surgery for glaucoma needed?

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.

A retrospective review of XEN implant surgery: efficacy, safety and the effect of combined cataract surgery

OBJECTIVES

To investigate the safety and efficacy of glaucoma XEN stent implantation and examine the effect of undergoing combined phacoemulsification and XEN versus XEN implant alone.

METHODS

A retrospective case note review of patients who underwent XEN implantation by a single surgeon over a 24-month period was performed. Outcomes included changes in IOP and medication use after XEN implant insertion as well as complications post-surgery. Subgroup analysis was also performed, separating phaco-XEN (phacoemulsification and XEN implantation) and stand-alone XEN implantation.

RESULTS

186 XEN implant procedures were included in this study from a total of 143 patients. Intraocular pressure changes with time were as follows: preoperative 18.1 mmHg (± 5.77), 6 months 13.2 mmHg (SD ± 3.9), 12 months 13.7 mmHg (SD ± 5.6) and 24 months 12.6 mmHg (SD ± 3.1). For visits up to 12 months, comparison from preoperative IOP was significant at the < 0.0001 level; for 18 and 24 months, significance was < 0.05. Medication usage with time was as follows: preoperative 2.5 (SD ± 1.1) 6 months 0.7 (SD ± 0.9), 12 months 0.8 (SD ± 0.97), and 24 months 1.7 (SD ± 1.7). All results were significant at < 0.05 level. Subgroup analysis of separate phaco-XEN and stand-alone XEN groups did not reveal significant differences in IOP; however, there was a significant difference between the two groups preoperatively. Initial hypotony occurred in 75 cases (40%). There were 9 cases of hypotonous maculopathy, 3 cases of persistent choroidal effusions, 3 cases of IOP spikes, 1 cases of cyclodialysis cleft and 1 case of corneal decompensation. 25 (13%) cases had needling during their treatment.

CONCLUSION

The XEN implant appears to be safe and effective at reducing intraocular pressure and medication usage in glaucoma patients. XEN implantation is an effective treatment option for a range of glaucoma types and can be used as a stand-alone procedure or combined with cataract surgery to treat glaucoma patients.

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.

Early Experience with the New XEN63 Implant in Primary Open-Angle Glaucoma Patients: Clinical Outcomes

The new XEN63 implant is a minimally invasive glaucoma surgery device with limited experience in real life. This retrospective study included open-angle glaucoma patients who underwent XEN63 implant, either alone or in combination with cataract surgery. Primary endpoints were the intraocular pressure (IOP) at month 3 and the incidence of serious adverse events. Twenty-three eyes of 23 patients were included. Mean age was 67.8 ± 15.3 years and 15 (65.2%) were women. Mean IOP was significantly lowered from 27.0 ± 7.8 mmHg at baseline to 12.2 ± 3.4 mmHg at month 3 (p < 0.0001). Mean IOP lowering was 40.8 ± 23.5%, with 14 (60.9%) and 16 (69.6%) eyes achieving an IOP lowering ≥30% and ≥20% without hypotensive medication, respectively. The number of hypotensive medications (NHM) was significantly reduced from 2.27 ± 0.94 drugs at baseline to 0.09 ± 0.42 drugs at month 3, p < 0.0001. Four (17.4%) eyes had hypotony (IOP ≤ 6 mmHg) at postoperative day one, which was successfully resolved without sequelae. Four (17.4%) eyes had choroidal detachment (3 at day 7 and 1 at day 15), which was successfully resolved with medical treatment, at the month 1 visit. Three (13.0%) eyes required needling (mean time for needling 35.6 ± 9.7 days). XEN63 significantly lowered IOP and reduced the NHM, with a good short-term safety profile.

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.

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.

Effective treatment of a normal-tension glaucoma patient with bilateral ab externo XEN Gel Stent implantation

Purpose

To provide the first report of effective use of bilateral XEN Gel Stent implantation using an ab externo open-conjunctival approach designed to improve bleb function and meet the uniquely low intraocular pressure requirements of a Japanese patient with normal-tension glaucoma refractory to topical medical therapy.

Observations

A 54-year-old phakic Japanese woman with severe normal-tension glaucoma on maximally tolerated medical therapy of four topical agents presented with above-goal intraocular pressures and new medication intolerances. She underwent bilateral ab externo open-conjunctival XEN Gel Stent implantation with tenectomy and sub-Tenon's injection of 40μg of mitomycin-C, which resulted in reduction of intraocular pressures by 41.2 and 28.6% to 10 and 10 mmHg in the right and left eyes, respectively at the most recent visit. Postoperatively, a diffuse filtering bleb with good morphology developed in both eyes. The procedure has so far allowed for complete cessation of all four topical medications for up to eight months following surgery without any serious complications.

Conclusions

This case illustrates the potential of Xen Gel Stent implantation through an ab externo, open-conjunctival approach to be an effective, simple alternative to trabeculectomy to meet the unique low-pressure requirements of normal-tension glaucoma patients with practical and safety benefits of a micro-invasive approach.

Cataract and glaucoma combined surgery: XEN® gel stent versus nonpenetrating deep sclerectomy, a pilot study

Background

To compare the efficacy of phacoemulsification (PKE) combined with nonpenetrating deep sclerectomy (NPDS) with mitomycin C (MMC) versus XEN® gel stent with MMC.

Methods

In this nonrandomized, retrospective, comparative, single-center pilot study, 105 consecutive eyes of 75 patients with uncontrolled primary open-angle glaucoma (POAG) and cataract who underwent PKE combined with either XEN implantation (n = 47) or NPDS (n = 58) between May 2013 and November 2018 were included. The primary outcome was complete success at 9 months, which was defined as intraocular pressure (IOP) ≤18, 15 or 12 mmHg without treatment; qualified success was IOP ≤18, 15 or 12 mmHg with antiglaucoma medications. Secondary outcome measures included the number of antiglaucoma medications, visual acuity (VA), and postoperative adverse events.

Results

Using the 18 mmHg threshold, complete or qualified success was achieved in 69.6 and 89.1% in the PKE + XEN group, and 63.8 and 89.7% in the PKE + NPDS group (p = .54 and p = .93), respectively, at 9 months. The mean IOP decreased from 20.8 ± 6.8 mmHg to 16.2 ± 2.8 mmHg in the PKE + XEN group (p < .001, 18.9% mean drop), and from 21.5 ± 8.9 mmHg to 14.9 ± 3.9 mmHg in the PKE + NPDS group (p < .001, 25.6% mean drop). Best-corrected VA significantly improved (p < .001) in both groups. The mean number of antiglaucoma medications was significantly reduced from 2.66 ± 1.1 to 0.49 ± 1.0 in the PKE + XEN group (p < .001) and from 2.93 ± 0.9 to 0.69 ± 1.2 in the PKE + NPDS group (p < .001).

Conclusions

The XEN stent combined with PKE seemed to be as effective and safe as PKE + NPDS at 9 months in this pilot study.

Lamellar sclerectomy augmented XEN gel stent glaucoma surgery

PURPOSE

To describe a surgical technique to optimize XEN gel stent position and its outflow.

METHODS

A small 1- to 1.5-mm square lamellar sclerectomy was created at the external tip of the XEN gel stent implant. The lamellar scleral tissue, served as a patch graft, was secured at the gel stent insertion site.

RESULTS

Four sequential, unselected, patients with failed primary XEN gel stent surgeries underwent bleb revisions with the technique described. These four patients achieved unmedicated intraocular pressures between 10 and 12 mmHg and a favourable bleb morphology despite repeated mitomycin C applications at 6 months.

CONCLUSION

Lamellar sclerectomy with auto-scleral graft augmented XEN gel stent surgery deliver successful short-term outcomes without major complications observed.