XEN-augmented Baerveldt Implantation for Refractory Childhood Glaucoma: A Retrospective Case Series

Transconjunctival XEN45 implantation for secondary open-angle glaucoma management in a pediatric patient with WAGR syndrome

Purpose

To report a case of XEN45 gel stent implantation in a pediatric patient with WAGR syndrome as a successful surgical intervention in the management of multifactorial secondary open-angle glaucoma.

Observations

A 6-year-old female with a history of WAGR syndrome, bilateral congenital aniridia, pseudophakia OD and glaucoma OD, was referred for a XEN45 gel stent OD. IOP was persistently elevated at 24 mm Hg despite two glaucoma medications. Implantation of the XEN45 gel stent was performed using a transconjunctival ab externo approach. There were no significant intra-or-postoperative adverse events associated with the stent. The patient achieved good IOP-lowering control without glaucoma medications across the 18-month follow-up period.

Conclusions

A XEN45 stent through a transconjunctival ab externo approach may be an effective surgical intervention in pediatric patients with secondary open-angle glaucoma associated with aniridia and aphakia.

Surgical outcomes of excisional goniotomy using the kahook dual blade in severe and refractory glaucoma: 12-month results

OBJECTIVES

To describe the efficacy and safety of goniotomy with trabecular meshwork excision using the Kahook Dual Blade (KDB, New World Medical Inc., Rancho Cucamonga, CA) in patients with severe or refractory glaucoma.

METHODS

This retrospective multicentre case series reports on 40 eyes with severe or refractory open-angle glaucoma that underwent standalone or combined KDB goniotomy and were followed for 12 months post-operatively in the United-States, Mexico and Switzerland. Surgical success was defined as an intraocular pressure (IOP) reduction ≥20% from baseline at 12 months, with fewer medications than preoperatively. Mean IOP and antiglaucoma medication reduction, probabilities of achieving an IOP ≤16 or 18 mmHg, and adverse events were also analysed.

RESULTS

Mean IOP decreased from 18.1 ± 5.0 mmHg at baseline to 14.8 ± 3.7 mmHg at 12 months (18.2% reduction, P < 0.001). Concomitantly, the mean number of glaucoma medications decreased from 2.5 ± 1.4 to 1.7 ± 1.2 (32% reduction, P = 0.002). The proportion of eyes achieving an IOP reduction of more than 20% from baseline was 37.5% (n = 15) at 12 months. At 12 months, 67.5% and 82.5% achieved a medicated IOP ≤ 16 and ≤18 mmHg, respectively. No severe complications were reported.

CONCLUSION

Excisional goniotomy with KDB achieves a statistically significant IOP and antiglaucoma medication reduction in severe or refractory glaucoma over a period of 12 months. While its efficacy decreases with time, its favourable safety profile makes it a potentially useful primary or adjunctive procedure in high-risk eyes.

Controversies in Pediatric Angle Surgery and Secondary Surgical Treatment

Pediatric glaucoma is a constellation of challenging ophthalmic conditions that, left untreated, can result in irreversible vision loss. The mainstay of treatment for primary congenital glaucoma and select secondary glaucoma subtypes is angle surgery, either trabeculotomy or goniotomy. More recently, MIGS devices have been utilized to enhance the efficacy of these procedures. Despite the high success rates of these primary surgical options, refractory cases are challenging to manage. There is no consensus on the next step of treatment following primary angle surgery. Glaucoma drainage devices and trabeculectomies have been the traditional options, with laser treatment reserved for more severe cases. The benefits and disadvantages of each of these options are discussed.

Pediatric Glaucoma-From Screening, Early Detection to Management

Pediatric glaucoma (PG) covers a rare and heterogeneous group of diseases with variable causes and presentations. Delayed diagnosis of PG could lead to blindness, bringing emotional and psychological burdens to patients' caregivers. Recent genetic studies identified novel causative genes, which may provide new insight into the etiology of PG. More effective screening strategies could be beneficial for timely diagnosis and treatment. New findings on clinical characteristics and the latest examination instruments have provided additional evidence for diagnosing PG. In addition to IOP-lowering therapy, managing concomitant amblyopia and other associated ocular pathologies is essential to achieve a better visual outcome. Surgical treatment is usually required although medication is often used before surgery. These include angle surgeries, filtering surgeries, minimally invasive glaucoma surgeries, cyclophotocoagulation, and deep sclerectomy. Several advanced surgical therapies have been developed to increase success rates and decrease postoperative complications. Here, we review the classification and diagnosis, etiology, screening, clinical characteristics, examinations, and management of PG.

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.

XEN-augmented Baerveldt Failure: Three Different Revision Approaches for Pediatric Patients

Aim and objective

Report three different solutions in case of XEN-augmented Baerveldt fails.

Background

Drainage devices have been used for refractory pediatric glaucoma. To avoid early hypotony and corneal damage, Mermoud et al. introduced the augmentation of a XEN implant with a Baerveldt tube. In some cases, this technique fails to lead to a high intraocular pressure (IOP) and surgical revision.

Case description

Three cases of children with this combined implant needed surgical revision due to high IOP. Three different approaches were performed: XEN replacement in one case, stretching the Baerveldt's tube into the anterior chamber (AC) in the second case, and explant of the device followed by an implant of a new Baerveldt-250 in the same quadrant in the third case. Successful control of IOP (>18 mm Hg) was achieved in all patients under no topical treatment.

Conclusion

Despite the attractiveness of the XEN-augmented Baerveldt implant in refractory pediatric glaucoma as an alternative to conventional surgery, we have to learn how to deal with failures. Three different approaches are presented with good short-term results. The long-term efficacy is yet to be assessed.

Clinical significance

Describe three possible options when faced with a need for surgical revision in XEN-augmented Baerveldt implant.

How to cite this article

José P, Abegão Pinto L, Teixeira FJ. XEN-augmented Baerveldt Failure: Three Different Revision Approaches for Pediatric Patients. J Curr Glaucoma Pract 2021;15(2):96–98.

Minimally Invasive Glaucoma Surgery: A Critical Appraisal of the Literature

Micro- or minimally invasive glaucoma surgeries (MIGS) have been the latest addition to the glaucoma surgical treatment paradigm. This term refers not to a single surgery, but rather to a group of distinct procedures and devices that aim to decrease intraocular pressure. Broadly, MIGS can be categorized into surgeries that increase the trabecular outflow [Trabectome, iStent (first and second generations), Hydrus microstent, Kahook Dual Blade and gonioscopy-assisted transluminal trabeculotomy], surgeries that increase suprachoroidal outflow (Cypass microstent and iStent Supra), and conjunctival bleb-forming procedures (Xen gel stent and InnFocus microshunt). Compared to traditional glaucoma surgeries, such as trabeculectomy and glaucoma drainage device implantation (Ahmed, Baerveldt, and Molteno valves), MIGS are touted to have less severe complications and shorter surgical time. MIGS represent an evolving field, and the efficacy and complications of each procedure should be considered independently, giving more importance to high-quality and longer-term studies.

A Retrospective Comparison of Trabeculectomy, Baerveldt Glaucoma Implant, and Microinvasive Glaucoma Surgeries in a Three-Year Follow-Up

Purpose: This retrospective study aimed to evaluate the safety and efficacy of MIGS (Xen® and Cypass®) compared to trabeculectomy and Baerveldt® implants.Patients and Methods: This single-center study included patients from the Ophthalmic Hospital of Turin between January 2015 and 2018.Efficacy was assessed based on the intraocular pressure and the number of medications necessary to control IOP at 1, 3, 6, 12, 24, and 36 months and the potential complications. Complete surgical success was defined as IOP ≤ 21 mmHg, with no medication or additional glaucoma surgery. Qualified success was defined as IOP ≤ 21 mmHg with the reintroduction of topical medications. Our third measure of success was a delta IOP reduction greater than 20% compared to baseline.Results: The delta IOP compared to the baseline was significant at every instance, except in the Xen® implant group. The average IOP distribution at different time points was significant, except at 1 and 12 months. The delta of the medication number compared to the baseline was significant at every instant. All three methods of success were analyzed using a Kaplan-Meier survival curve that identified a significant difference on the success rates of Xen®-trabeculectomy, Xen®-Baerveldt®, and Cypass®-Baerveldt®.Conclusion: MIGS can reduce the number of medication classes, thus increasing patient compliance and reducing topical ocular toxicity and general costs. Trabeculectomy remains the most effective option but still presents a percentage of failures that might increase during follow-up.

Efficacy and Safety of the Susanna Glaucoma Drainage Device After 1 Year of Follow-up

PRECIS

This study found a rate of failure of 13.6% of the new Susanna Glaucoma Drainage Device (SGDD) after 1 year of follow-up. Severe complications occurred in 1 patient (4.5%).

PURPOSE

The purpose of this study was to determine the success and complications rates of the SGDD implant in refractory glaucoma.

PATIENTS AND METHODS

This is a retrospective study. Medical records from all consecutive refractory glaucoma patients (failed trabeculectomies with the use of adjunctive mitomycin) followed in a private clinical practice were included in the study. All patients had undergone SGDD implant surgery from September 2016 to July 2019 were included. All surgeries were done by the same surgeon (R.S.). Primary outcome was surgical failure, defined as intraocular pressure (IOP) >18 mm Hg and/or <20% IOP reduction from baseline, IOP<5 mm Hg, reoperation for glaucoma, need of implant removal or loss of light perception vision. Secondary outcomes included mean IOP, use of supplemental medical therapy, and complications.

RESULTS

In all, 22 eyes were analyzed. Mean patient age was 63±15 years (range: 27 to 87 y). Mean IOP decreased from 23±7 to 11±8 mm Hg (P<0.001, paired t test) at an average of 18±9 months after the tube implant. The mean SD number of glaucoma medications was reduced from 3.3±1 to 1.5±1.2 at the last postoperative visit (P<0.01, paired t test). No early postoperative complications occurred. There was 1 case of late persistent hypotony in a patient with previous endocyclophotocoagulation that was solved with tube ligature with silk 8-0. Failure because of high IOP occurred in 2 cases. There was no extrusion or erosion of the tube and the plate.

CONCLUSION

The SGDD presented a 13.6% failure rate (86.4% success rate) with very few complications, being an efficient and safe alternative for refractory glaucoma.

XEN-augmented Baerveldt surgical success rate and comparison with the Ahmed Valve

PURPOSE

The Baerveldt-XEN technique is intended to reduce the risk of early hypotony after Baerveldt implant, while keeping a good long-term intra-ocular pressure (IOP) control. The aim of this study is to discuss the surgical success rate of the Baerveldt-XEN and compare it with the commercially available flow-restrictor device (Ahmed glaucoma valve - AGV).

METHODS

Single-centre, cohort study. Consecutive glaucoma patients with uncontrolled IOP > 21 mmHg on maximum tolerated medical therapy, and who had an aqueous shunt as the planned surgical procedure. Patients underwent implantation of Baerveldt-XEN. An age-, gender- and glaucoma aetiology-matched database of AGV patients was used for comparison. Complete surgical success was defined as a final IOP between 6 and 21 mmHg, and 20% reduction from baseline with no need for IOP-lowering medication. Qualified success was the same criteria but resorting to medications.

RESULTS

Twenty-four eyes from 24 subjects with glaucoma were included in this study, 12 patients underwent Baerveldt-XEN implantation and 12 AGV. Twelve months after the Baerveldt-XEN implant, the IOP reduced from 33 ± 9 mmHg to 14 ± 3 mmHg (p < 0.001). The qualified and complete success rate was 50% and 25%, respectively. With the AGV, the IOP reduced from 29 ± 7 mmHg to 16 ± 7 mmHg (p = 0.001). The matched AGV group compared to the Baerveldt-XEN, presented a higher complete success rate (58.3%) and a qualified success rate of 33.3% (p = 0.72). No sight-threatening complications were recorded in both groups.

CONCLUSIONS

The Baerveldt-XEN disclosed a low complete success rate at 1 year of follow-up, although with no major safety concerns. While studies with a longer follow-up are needed to demonstrate the potential advantages and disadvantages of the Baerveldt-XEN, this technique may be less likely to achieve drop-free efficacy when compared to other flow-restrictor strategies.

XEN-augmented Baerveldt drainage device implantation in refractory glaucoma: 1-year outcomes

PURPOSE

To evaluate outcomes of XEN-augmented Baerveldt drainage device implantation in refractory glaucoma and factors predicting surgical success.

METHOD

All eyes undergoing XEN-augmented Baerveldt for refractory open-angle glaucoma at a tertiary glaucoma centre between January 2016 and November 2017 were retrospectively enrolled. Intraocular pressure (IOP), number of anti-glaucomatous medications and postoperative adverse events (AEs) were analysed for 1 year postoperatively. Surgical success was defined as achieving (1) an IOP ≤ 15 mmHg or (2) ≤ 18 mmHg, with or without (qualified) or without medications (complete). Any subsequent glaucoma surgery was considered failure.

RESULTS

Out of 60 eyes enrolled, 12-month data were available for 41 eyes (71.4%). Mean age was 64.7 ± 23.1 years (50% female). Following surgery, IOP decreased significantly from a baseline of 29.9 ± 13.2 to 15.2 ± 6.6 mmHg (- 49.2%; P < 0.0001) at 12 months. Anti-glaucoma medications decreased from 3.0 ± 1.3 to 1.3 ± 0.9. Complete success was achieved by 14.6% of eyes using both the ≤ 15 mmHg and the ≤ 18 mmHg thresholds, and qualified success was achieved in 43.9% and 48.8%, respectively. Throughout the follow-up period, AEs were observed in 51.2% (hypotony = 24.4%; XEN blockage = 17.1%; displacement of XEN gel stent = 4.9%; hyphema = 4.9%). The 12-month success rate was significantly higher in patients who presented an IOP ≤ 10 mmHg at 1 week (58.6%, P = 0.001). Overall, 41.5% of patients required reoperation at 12 months (58.8% revision of the surgery; 41.2% transscleral cyclodestruction).

CONCLUSION

XEN-augmented Baerveldt is a safe and moderately effective technique to reduce IOP and anti-glaucoma medications in refractory glaucoma. IOP at 1 week seems to be a predictor for surgical success. Nevertheless, a high proportion of patients requires reoperation.

Contemporary management of refractory pediatric glaucoma

PURPOSE OF REVIEW

The management of pediatric glaucoma poses a unique challenge in terms of maintaining lifelong vision and combating an aggressive scarring response from surgery. Contemporary literature regarding the surgical management of children with pediatric glaucoma who fail, or are at a high risk of failure, from conventional surgery is limited. The aim of this review is to highlight recent developments in relation to the current opinion regarding the management of children with refractory pediatric glaucoma.

RECENT FINDINGS

Some studies have reported impressive success rates with circumferential trabeculotomy, even in eyes with previous failed surgery. Early results of deep sclerectomy in populations which may not respond well to conventional angle surgery are encouraging but data is limited for the pediatric age group. In compliant patients in whom multiple postoperative examinations under anesthesia are possible, trabeculectomy remains an effective procedure. Multiple recent studies have demonstrated that glaucoma drainage device (GDD) surgery is associated with 5-year success rates of over 70% in primary childhood glaucomas.

SUMMARY

Glaucoma drainage device surgery is likely to remain a mainstay of surgical management for refractory glaucoma in older children. More prospective data are needed on the success of circumferential trabeculotomy, deep sclerectomy and micropulse laser in pediatric eyes with previous failed surgery. VIDEO ABSTRACT: http://links.lww.com/COOP/A34.