Impact of Primary Needling on the XEN Implant Clinical Outcomes: A Real-Life Retrospective Study

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

BACKGROUND

Minimally invasive bleb surgery using the XEN-45 gel stent has not been established for the treatment of normal-tension glaucoma (NTG). The main objective of this study was to evaluate the long-term treatment efficacy and safety of XEN-45 in eyes with uncontrolled NTG.

METHODS

A retrospective analysis of patients with NTG who underwent XEN-45 gel stent implantation at university hospital Tuebingen between 2016 and 2021. The primary outcome measure was surgical success after three years defined as lowering of intraocular pressure (IOP) of ≥ 20%, with target IOP between 6 and 15 mmHg. Success was complete without and qualified irrespective of topical antiglaucoma medication use. The need for further glaucoma surgery, except for needling, was regarded as a failure. The secondary outcome measures included changes in mean IOP, number of antiglaucoma medications, and needling and complication rates.

RESULTS

Twenty-eight eyes from 23 patients were included in the final analysis. Complete and qualified success rates were 56.5% and 75% after three years, respectively. Mean postoperative IOP ± standard deviation decreased significantly after three years from 19.3 ± 2.0 mmHg at baseline to 13.7 ± 4.2 mmHg (n = 22; p < 0.0001). The median number of antiglaucoma medications decreased from 2 (range 0-4) to 0 after three years (range 0-3; p < 0.0001). Sixteen eyes (57%) required a median of 1 (range 1-3) needling procedures. One eye required further glaucoma surgery. No sight-threatening complications were observed.

CONCLUSION

The XEN-45 stent is effective and safe for the long-term treatment of NTG. However, needling was frequently required to improve outcomes.

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.

Efficacy and safety of combined Xen Gel Stent-45 implantation and 25-gauge Pars Plana Vitrectomy: a case series

Purpose: To report outcomes in terms of efficacy and safety of patients affected with Primary Open Angle Glaucoma (POAG) and Vitreoretinal Disease, who have undergone Pars Plana Vitrectomy (PPV) and ab-interno XEN gel 45 (Abbvie) implantations. Methods: This is a retrospective, observational, case series on five patients who underwent combined Pars Plana Vitrectomy and XEN gel Stent 45 implantation at "Careggi Hospital" Eye Clinic of Florence. Best-corrected visual acuity (BCVA) evaluation, intraocular pressure (IOP) measurements with Goldmann applanation tonometer (GAT), and several glaucoma medications were evaluated at the baseline and at one, three, six, and twelve months after surgery. Complications were recorded up to 1 year after surgery. Results: 5 eyes in five patients were enrolled. IOP dropped from an average of 21,2 ± 3,3 mmHg preoperatively to 14,6 ± 1,1 mmHg at the end of the follow-up period (month 12), with a mean percentage reduction of 58%. One patient needed a needling procedure (20%). None needed reintervention. We did not register any case of hypotony (IOP < 6,5 mmHg), hypotony maculopathy and choroidal detachment. The postoperative number of anti-glaucomatous molecules was on average 0,2 ± 0,4. Conclusion: Our results suggested that combined Pars Plana Vitrectomy and XEN gel stent 45 implantation is safe and effective for patients affected by visually significant vitreoretinal diseases and POAG. Abbreviations: AC = anterior chamber, BCVA = Best-corrected visual acuity, ERM = epiretinal membrane, FTMH = full-thickness macular holes, FU = fluorouracil, GAT = Goldmann applanation tonometer, IOP = intraocular pressure, MIGS = minimally invasive glaucoma surgery, MMC = mitomycin C, NVG = neovascular glaucoma, OCT = optical coherence tomography, POAG = Primary Open Angle Glaucoma, PPV = Pars Plana Vitrectomy, SD = standard deviation, TB = Trabeculectomy, VF = visual field, VMI = Vitreomacular Interface, VMA = vitreomacular adhesion, VMT = vitreomacular traction.

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.

XEN Gel Stent Versus Nonpenetrating Deep Sclerectomy in Ocular Hypertension and Open Angle Glaucoma Patients

PRCIS

XEN gel stent and nonpenetrating deep sclerectomy, both either alone or in combination with cataract surgery, significantly lowered the intraocular pressure (IOP) and reduced the number of antiglaucoma medications in patients with open angle glaucoma, with no significant differences between them.

PURPOSE

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

CONCLUSIONS

XEN45 implant and the NPDS, either alone or in combination with cataract surgery, significantly lowered IOP and reduced the number of ocular hypotensive medications in ocular hypertension and patients with open angle glaucoma.