Needling With 5-Fluorouracil (5-FU) After XEN Gel Stent Implantation: 6-Month Outcomes

Factors Associated with the Efficacy of XEN Gel Implant

INTRODUCTION

Microinvasive glaucoma surgery (MIGS) is a growing trend, and XEN gel implant is one of the most effective types of MIGS. This study aimed to examine factors associated with the surgical success of XEN gel implants.

METHODS

This retrospective cohort study enrolled patients with glaucoma receiving XEN implantation alone or combined with phacoemulsification (PHACOXEN) with a follow-up period of more than 6 months at Hualien Tzu Chi Hospital, Taiwan. If intraocular pressure (IOP) elevated above 20 mmHg during the follow-up, needling or open revision was performed. The primary outcome measures included IOP and the number of glaucoma medications.

RESULTS

Male patients had lower postoperative IOP; male patients and higher preoperative IOP were associated with higher IOP change rates, and older patients had a higher chance of achieving IOP < 18 mmHg and being medication-free at months 12, 24, and 36. The Kaplan-Meier curve showed that the probability of free-of-rescue intervention over the follow-up period was not different between the XEN alone and the PHACOXEN group (P = 0.859). Both needling and open revision were effective rescue interventions, but open revision had a higher chance of achieving IOP ≤ 18 mmHg and being medication-free (P = 0.031) and required less medication afterward (P = 0.044). Older age (P = 0.013) and male patients (P = 0.022) had a lower IOP after rescue interventions. Compared with open revision, needling was associated with higher IOP (P = 0.048) and more required medications (P = 0.048).

CONCLUSIONS

XEN alone and PHACOXEN had comparable surgical outcomes, whereas open revision had a better IOP lowering effect than needling as a rescue intervention. Male and older patients had better surgical results in primary XEN implantations and rescue interventions.

Recent Advancements in Glaucoma Surgery-A Review

Surgery has long been an important treatment for limiting optic nerve damage and minimising visual loss in patients with glaucoma. Numerous improvements, modifications, and innovations in glaucoma surgery over recent decades have improved surgical safety, and have led to earlier and more frequent surgical intervention in glaucoma patients at risk of vision loss. This review summarises the latest advancements in trabeculectomy surgery, glaucoma drainage device (GDD) implantation, and minimally invasive glaucoma surgery (MIGS). A comprehensive search of MEDLINE, EMBASE, and CENTRAL databases, alongside subsequent hand searches-limited to the past 10 years for trabeculectomy and GDDs, and the past 5 years for MIGS-yielded 2283 results, 58 of which were included in the final review (8 trabeculectomy, 27 GDD, and 23 MIGS). Advancements in trabeculectomy are described in terms of adjunctive incisions, Tenon's layer management, and novel suturing techniques. Advancements in GDD implantation pertain to modifications of surgical techniques and devices, novel methods to deal with postoperative complications and surgical failure, and the invention of new GDDs. Finally, the popularity of MIGS has recently promoted modifications to current surgical techniques and the development of novel MIGS devices.

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.

Two-year Outcomes of XEN Implantation with Minimal Bleb Needling

Aim

Our study aims to report the 2 years outcomes of the XEN implant in a single unit, single surgeon setting with minimal bleb needling.

Methods

A retrospective cohort study was conducted. Inclusion criteria were patients who underwent implantation with a XEN device between May 2016 and December 2017. This included patients who underwent both combined phacoemulsification and intraocular lens implantation alongside XEN implantation and those who underwent XEN implantation alone. Data gathered included basic demographic data, best-corrected visual acuity (LogMAR), intraocular pressure (IOP) in mm Hg, mean deviation from their visual field test, and the number of IOP-lowering medications they were on. This information was recorded for their preoperative visit, and then at 6, 12, 18 and 24 months postoperatively. The primary outcome assessed was a complete success when the patient was without glaucoma medications and had an IOP of 18 mm Hg or less, but more importantly, this also had to equate to a 20% reduction in IOP compared to baseline. Qualified success was defined as the same change in IOP but with medications. Surgical failure is defined as those who required additional glaucoma surgery or those who did not obtain an IOP of 18 mm Hg alongside a 20% reduction in IOP compared to baseline.

Results

At 24 months follow-up 82.5% of patients were surgical successes. Complete surgical success was achieved in 27% of patients. Qualified surgical success was achieved in 55.6% of patients. Subgroup analysis of those undergoing XEN implantation on its own and those combined with phacoemulsification + IOL were similar. The rate of bleb needling was low at 4.5%. Complication rates were acceptable at 9.5%.

Conclusion

It is possible to get good IOP control with minimal postoperative bleb needling in patients who have undergone XEN implantation. Similar success rates are found in those undergoing combined procedures.

Clinical Significance

Bleb needling carries its own risks. Minimizing the number of bleb needling allows procedures to be reserved at a later date. Furthermore, our study shows that success rates are not affected by doing a combined procedure with phacoemulsification.

How to cite this article

Ali ZC, Moshin N, Hakim MT, et al. Two-year Outcomes of XEN Implantation with Minimal Bleb Needling. J Curr Glaucoma Pract 2022;16(2):79-83.

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.

Surgeon Experience as a Risk Factor for Short-Term Failure for Ab Interno Gelatin Microstent: A Canadian Multicenter Propensity-Matched Study

PURPOSE

To compare the efficacy and safety of early versus later ab interno gelatin microstent placement with mitomycin C.

DESIGN

Canada-wide, multicenter, retrospective propensity score-matched cohort study.

PARTICIPANTS

Two hundred seventy eyes (135 early cases and 135 later cases) with no prior incisional surgery.

METHODS

Surgeons' first 20 patients (early cases group), from 6 glaucoma surgeons across 4 Canadian sites, were matched 1:1 to patients with the closest propensity score from the later (21+) patients (later cases group).

MAIN OUTCOME MEASURES

Primary outcome was hazard ratio (HR) of failure of the early versus later cases groups, with failure defined as IOP of less than 6 mmHg with more than 2 lines of vision loss or more than 17 mmHg with no medications (complete success) on 2 consecutive visits despite in-clinic maneuvers (including needling) more than 1 month after surgery. Secondary outcomes were HRs for failure, defined as IOP outside the range of 6 to 14 mmHg and 6 to 21 mmHg with and without allowing for medications (qualified success), interventions, complications, and reoperations.

RESULTS

Hazard ratio of failure for early versus later cases groups was 1.38 (95% confidence interval [CI], 0.97-1.96) for the IOP range of 6 to 17 mmHg, 1.29 (95% CI, 0.90-1.84) for 6 to 14 mmHg, and 1.48 (95% CI, 1.03-2.13) for 6 to 21 mmHg without medication and 0.95 (95% CI, 0.55-1.64), 0.95 (95% CI, 0.61-1.48), and 0.95 (95% CI, 0.52-1.75) for the same IOP ranges allowing for medications. Needling rates were 43.0% (early cases group) and 41.5% (later cases group). Complication rates after 1 month occurred in 9.6% (early cases group) and 11.1% (later cases group; P = 0.69). Reoperation rates were 14.8% (early cases group) and 8.1% (later cases group; P = 0.08).

CONCLUSIONS

There is some evidence for improved success in the later cases group. Similar needling rates, similar complication rates, and a slightly higher reoperation rate were found for the early cases group. The results suggest that this procedure can be adopted by existing surgeons with current training regimens, although they may see an improvement in their success outcomes over time.

Comparative outcome analysis of bleb needling of fibrotic blebs in the clinic versus the operating room: a retrospective case series

BACKGROUND

To compare 6 month outcomes of bleb needling performed in the clinic vs. the operating room (OR) in adult glaucoma patients with failed bleb.

METHODS

A retrospective case series of 47 eyes from 41 glaucoma patients who received needling with mitomycin C (MMC) of scarred bleb from prior bleb-forming procedures in clinic (32 eyes) vs. the OR (15 eyes), including trabeculectomy (14 eyes), ExPress shunt (16 eyes), and ab-interno XEN gel stent (17 eyes). The primary outcome was needling success, defined as IOP ≤ 18 mmHg on 0 glaucoma medications without requiring an additional IOP lowering procedure within 6 months after needling.

RESULTS

At 6 months, bleb needling success rate was similar when performed in the clinic vs. in the OR (28% vs. 20%, P = 0.54). Success rate was not statistically different in patients with prior trabeculectomy, ExPress shunt, and XEN gel stent (29% vs. 38% vs. 12%, P = 0.26). When comparing clinic vs. the OR needling procedures at 6 months, there was no difference in mean IOP (14.2 vs. 14.9 mmHg, P = 0.73), mean glaucoma medications (1.4 vs. 1.7, P = 0.69), additional IOP-lowering procedure rate (16% vs. 27%, P = 0.37), or complication rate (0% vs. 7%, P = 0.32).

CONCLUSION

Bleb needling with MMC in clinic may be a safe and effective way to revise failed bleb after trabeculectomy, ExPress shunt, and XEN gel stent procedures when compared to needling in the OR.

Results of fluorouracil-augmented Xen45 implantation in primary open-angle and pseudoexfoliation glaucoma

PURPOSE

To report the effectiveness and safety of 5-fluorouracil (5-FU)-augmented Xen45 implantation in primary open-angle glaucoma (POAG) and pseudoexfoliation glaucoma (PEXG).

METHODS

This single-center, retrospective chart review study included 29 eyes that underwent 5-FU-augmented Xen45 implantation. Main outcome measures were intraocular pressure (IOP) levels and number of glaucoma medications. Surgical success was defined as IOP ≤ 21 mmHg and ≥ 20% reduction from preoperative levels without (complete success) or with (qualified success) glaucoma medications and without further glaucoma surgery at last follow-up. All postoperative interventions and complications were also noted.

RESULTS

The mean age of the patients was 67.5 ± 10.3 years, and the mean follow-up time was 23.2 ± 12.6 months. Mean IOP was 24.5 ± 8.7 mmHg and decreased by 30.2% at 12 months, 24.9% at 24 months, and 31.7% at final visit (p < 0.001, p = 0.006, p > 0.001, respectively). Mean number of glaucoma medications decreased from 2.83 preoperatively to 0.71 at 12 months, 0.87 at 24 months, and 0.86 at final visit (p < 0.001). At final visit, the complete success rate was 48.3%, qualified success rate was 69%, and 62.1% of the eyes were free of glaucoma medications. Needling was performed in 7 eyes (24%). Adverse events included choroidal detachment in 5 eyes, hyphema in 2 eyes, and endophthalmitis in 1 eye.

CONCLUSION

5-FU-augmented Xen45 implantation in POAG and PEXG patients provided safe and effective IOP lowering with significant reduction of glaucoma medications up to 3 years.

Needling after XEN gel implant: What's the efficacy? A 1-year analysis

PURPOSE

To analyse the long-term efficacy and safety of bleb needling in glaucoma patients previously submitted to XEN implantation.

METHODS

Retrospective, observational study. Charts from patients who underwent XEN gel implant surgery between October 2015 and December 2017 were reviewed. Needling protocol involves use of Mitomycin C 0.2 mg/mL in an operating room. Primary outcome was defined as intraocular pressure (IOP) lowering efficacy at 12 months post-operative. Complete success was defined as a decrease in IOP > 20% and overall value <18 mmHg. Secondary outcomes included safety parameters (both intra and post-operative). Exploratory analysis of predictive factors for success were performed. Statistical analysis was performed using SPSS version 24.

RESULTS

About 94 charts were reviewed, with 18 patients (19%) having undergone needle revision. This salvage procedure was performed after 3.3 ± 3.4 months, achieving a mean IOP reduction of 8.3 ± 8.4 mmHg at 12 months after the procedure (pre-needling: 24.0 ± 5.2 mmHg vs 12th month: 13.5 ± 5.9 mmHg, p < 0.0001). Accordingly, success was achieved in 72% (complete success in 61% of cases). Among predictive factors, there was a higher tendency for success in patients on two types of medications or fewer pre-operatively, cases of standalone XEN surgery and patients with a higher IOP difference pre-needling - day 1. No vision-threatening complications were recorded.

CONCLUSION

XEN salvage procedure with mitomycin C is a valid option in early bleb failure. This single intervention had a long-lasting effect on bleb survival, with almost two-thirds achieving long term significant drop-free IOP reduction.

XEN Implant Fracture During Needling Procedure

PURPOSE

The XEN implant is a small hydrophilic stent designed to be implanted permanently for the treatment of glaucoma. As with other bleb-forming surgical procedures, needling is part of postoperative care. We describe 3 cases of XEN fracture of the subconjunctival portion that occurred during the needling procedure.

METHODS

The purpose of this study was to describe the clinical and anatomic outcomes in 3 cases of XEN fracture caused by the needling procedure.

RESULTS

In our case series of XEN procedures (n=170), bleb needling has been performed in 98 cases (57.6%). In 3 cases (3.1%), we observed unintentional damage to the implant after the procedure.The mean distal segment length of the fractured XEN measured 0.83 (range: 0.7 to 1) mm. Despite the adverse event, the mean IOP changed from 25.0 (range: 21 to 30) mm Hg before needling to 12.0 (range: 10 to 14) after needling, with a mean follow-up of 15.3 (range: 11 to 18) months. No vision-threatening complications were recorded during the entire follow-up.

CONCLUSIONS

XEN fracture related to the needling procedure should be considered as a possible adverse event of bleb management. Because XEN is composed of a soft and flexible gelatin material, it could be easily damaged by the needle. The fracture does not seem to impair the efficacy of the draining device. As a matter of fact, according to Poiseuille's laws, shortening of the implant's length decreases the resistance while increasing the flow rate. Despite our positive results, it is recommended to preserve the integrity of the implant.

Efficacy of postoperative management with 5-fluorouracil injections after XEN Gel Stent implantation

Purpose

To evaluate the efficacy of postoperative management with 5-fluorouracil injections after XEN Gel Stent implantation.

Methods

Prospective real-world evidence study included 39 eyes (of 36 patients) with primary open-angle glaucoma without previous glaucoma surgery and with uncontrolled intraocular pressure (IOP), glaucoma progression, or intolerance to IOP-lowering therapy. Patients underwent mitomycin C-augmented XEN implantation either as a stand-alone procedure or combined with cataract extraction. 5-Fluorouracil subconjunctival injections were a first-choice therapy for bleb failure and were administered according to predetermined criteria (analogous to pro re nata regimen in age-related macular degeneration treatment). Primary outcome was unqualified success, defined as postoperative IOP < 18 mmHg and > 20% reduction from medicated baseline without any antiglaucoma medications and no detected glaucoma progression.

Results

At median follow-up of 8 months (range 3–24 months), IOP decreased from a medicated baseline value of 23 mmHg (95% CI 21–24 mmHg) to 13 mmHg (95% CI 12–15 mmHg) and number of medications decreased from 3 (95% CI 2–3) to 0 (p < 0.0001 for both). Median number of 5-fluorouracil injections per eye was 3 (95% CI 2–3), and median time to first injection was 0.5 months (95% CI 0.25–3 months) after surgery. Thirteen eyes (33.3%) underwent ≥ 1 needling, and surgical revision was performed in three cases (7.7%). The primary outcome measure, which allows performing additional procedures, was achieved in 27 eyes (69%).

Conclusions

5-Fluorouracil subconjunctival injections are safe and effective in postoperative management of bleb failure after XEN implantation and represent a viable alternative to other methods.

Recommendations for the management of elevated intraocular pressure due to bleb fibrosis after XEN gel stent implantation

Surgical management of glaucoma offers a means of effective disease control. A gel stent that facilitates drainage to the subconjunctival space offers intraocular pressure (IOP) reduction similar to traditional glaucoma filtering surgeries in a less invasive manner. However, like all subconjunctival filtering procedures that result in a bleb, fibrosis can present as a cause of elevated IOP. The following proposed techniques and recommendations for managing elevated IOP due to bleb fibrosis after gel stent implantation are based on the clinical experience of the authors. The goal of this paper is to improve outcomes following gel stent surgery by providing guidance on assessment of bleb function and strategies for bleb enhancement.