XEN 45 Gel Stent Implantation in Open Angle Glaucoma: 5-Year Results of a Prospective Study

Long-Term Morphological Changes of Crosslinked Gelatin Stent

BACKGROUND

This study investigates the long-term morphological outcomes of crosslinked gelatin stents over a 10-year period.

METHODS

Participants from the FDA phase 1 and 2 trials for the XEN 140 stent were recalled for follow-up examinations between 9 and 12 years after their initial implantation. The stent area was evaluated using anterior segment optical coherence tomography (AS-OCT) in conjunction with clinical assessments. We focused on measuring specific alterations in stent dimensions, such as external surface pitting or 'nibbling', complete wall breaches and luminal obstruction.

RESULTS

We evaluated 11 eyes from 9 patients, with an average follow-up period of 11.2 years (SD ± 0.7). The mean preoperative intraocular pressure (IOP) was 22.5 mmHg (SD ± 4.9), which decreased to 14.7 mmHg (SD ± 1.2) a decade after surgery. Notably, four eyes no longer required antiglaucoma medication. Out of the 11 cases, only 8 yielded image quality suitable for analysis, all of which exhibited stent wall nibbling. The average nibbling depth was 70.17 μm (SD ± 36) in the intrascleral area, 79.5 μm (SD ± 18) in the proximal conjunctival region and 42.25 μm (SD ± 5) in the distal conjunctival region. Nibbling was most frequent in the proximal conjunctival area with 26 instances (p = 0.0006), followed by the intrascleral area, 21, and the distal conjunctival section, 9. Hyperreflective lumens were noted in five cases, with one complete stent wall discontinuity.

CONCLUSION

In cases where imaging provided clear visibility, the stents exhibited signs of morphometric changes after 11 years. This degradation process seems to initiate externally, leading to luminal obstruction and eventual stent failure.

Cataract surgery combined with glaucoma surgery

PURPOSE OF REVIEW

This review evaluates the surgical management of glaucoma in patients undergoing cataract surgery. Combining both procedures present challenges in balancing intraocular pressure (IOP) control, minimizing postoperative complications, and achieving optimal refractive outcomes.

RECENT FINDINGS

Recent studies highlight the effectiveness of combined glaucoma and cataract surgeries, with traditional filtering surgeries and MIGS showing significant IOP reduction. The abundance of long-term studies shows that MIGS can offer an effective and safer alternative when carefully tailored to meet the specific needs of each patient.

SUMMARY

Combining glaucoma and cataract surgery is a promising approach for patients with coexisting conditions. While traditional surgeries offer robust IOP reduction, MIGS procedures offer better safety profiles with fewer complications and more predictable refractive results. Surgeons must carefully consider the timing and choice of procedures, with further research required to develop standardized treatment algorithms.

Two-year outcomes of Xen 45 gel stent implantation in patients with open-angle glaucoma: real-world data from the Fight Glaucoma Blindness registry

OBJECTIVE

To evaluate efficacy and safety outcomes of the Xen 45 gel stent implant over 24 months of follow-up.

METHODS

A retrospective analysis of prospectively collected data from the Fight Glaucoma Blindness observational registry. Complete success (CS) was defined as intraocular pressure (IOP) reduction ≥20% from preoperative and an IOP ≤18 mm Hg and ≥6 mm Hg with no secondary procedure at 2 years and without IOP-lowering medications. Qualified success (QS) was defined similarly, allowing the use of IOP-lowering medications.

RESULTS

The Xen 45 gel stent implant was implanted in 646 eyes of 515 patients. Preoperative IOP was 21.4±7.6 (mean±SD) mm Hg on 2.7±1.3 IOP-lowering medication and mean deviation was -10.2±8.4 dB. After 24-month follow-up, IOP was 16.8±7.3 mm Hg (mean reduction of 21.7%) on 1.2±1.4 IOP-lowering medications. CS and QS rates at 24 months were 26% and 48%, respectively. CS and QS were higher in the Xen stand-alone group (33% and 52%, respectively) than in the Xen+cataract group (16% and 42%, respectively). Bleb needling was performed in 28.4% of cases, and 18% underwent a secondary procedure.

CONCLUSIONS

The Xen 45 gel stent implant offers acceptable long-term efficacy for the treatment of open-angle glaucoma. However, there is a significant rate of reoperation and needling, and outcomes are less effective if combined with cataract surgery.

Minimally Invasive Glaucoma Surgery: Latest Developments and Future Challenges

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