Clinical Outcomes and Cost Analysis of PreserFlo versus Trabeculectomy for Glaucoma Management in the United Kingdom

Intermediate-term impact on corneal endothelial cells and efficacy of Preserflo MicroShunt implantation in patients with open-angle glaucoma - a prospective study over two years

INTRODUCTION

Preserflo MicroShunt is a novel microinvasive bleb forming device for the treatment of primary open-angle glaucoma. The intermediate- and long-term success and the impact of this procedure on corneal endothelial cell density remain to be investigated.

METHODS

In this prospective observational study, 62 eyes of 55 glaucoma patients (mean age ± SD: 67.0 ± 15.0 years) receiving a Preserflo MicroShunt were included. Corneal endothelial cell density, intraocular pressure and best corrected visual acuity were assessed preoperatively and at 3, 6, 9, 12, 18 and 24 months postoperatively. Success rates, bleb revision rates and complications were analysed. Complete success was defined as an intraocular pressure reduction of ≥ 20% and achieving a target pressure of ≤ 18, ≤ 15 or ≤ 12 mmHg without antiglaucoma medication. Qualified success indicated that the criteria were reached with or without medication.

RESULTS

Corneal endothelial cells showed no significant decline over 24 months (p > 0.05). Intraocular pressure showed a substantial reduction postoperatively (p < 0.001), decreasing from 29.6 ± 8,3 mmHg to 13.0 ± 4.3 mmHg after 24 months (p < 0.001). Complete and qualified success with a target pressure ≤ 15 mmHg was achieved in 52.9% and 54.6% of cases after 24 months, respectively. Best corrected visual acuity did not change after 24 months.

CONCLUSION

Preserflo MicroShunt had no negative side effects on corneal endothelial cells and showed favourable success rates after 2 years in patients with open-angle glaucoma.

Trends in glaucoma surgery in a tertiary hospital in Spain: 2010-2022

OBJECTIVE

This study aims to conduct an analysis glaucoma surgeries performed over a 13-year period at a tertiary hospital affiliated with the Spanish National Health System, with the goal of assessing temporal trends.

METHODS

This retrospective observational study scrutinized surgeries undertaken in the glaucoma unit of a tertiary center in Spain between 2010 and 2022. Data collected included surgical dates, procedure performed, whether it was standalone or combined, as well as patient demographics including age, sex, and type of underlying glaucoma. Surgeries on individuals under 18 years of age were excluded. An annual comparative analysis was performed to ascertain the evolving trends in glaucoma surgical interventions.

RESULTS

A total of 12,944 surgeries were included in the analysis, comprising 9428 isolated cataract surgeries and 2975 glaucoma procedures. Trabeculectomy, glaucoma drainage devices (GDD), and cyclodestruction, collectively referred to as traditional surgery, demonstrated a decline from 93.2% to 23.6% over the study duration. Minimally invasive glaucoma surgery (MIGS) and minimally invasive bleb surgery (MIBS) demonstrated a significant increase from 3.8% in 2010 to 74.7% in 2022, relative to the total glaucoma surgeries. Furthermore, combined surgeries manifested a noteworthy increase from 39.0% in 2010 to 44.2% in 2022, with 86.4% of combined procedures in 2022 being MIGS or MIBS.

CONCLUSION

In recent years, there has been a noticeable change in the trend of glaucoma surgeries, with MIGS and MIBS procedures experiencing a significant increase and becoming the most commonly performed glaucoma procedures. Consequently, traditional glaucoma surgeries have decreased in frequency.

Conjunctival Advancement Procedure for Repairing Conjunctival Exposure of the PreserFlo MicroShunt

A 59-year-old Japanese woman with primary open-angle glaucoma underwent PreserFlo MicroShunt (PFM) (Santen Pharmaceutical Co., Ltd., Osaka, Japan) implantation in her left eye. Six weeks postoperatively, a conjunctival exposure of the posterior end of the device was observed, accompanied by aqueous leakage. The patient had no identifiable risk factors for exposure, such as previous conjunctival incisional surgeries, significant blepharitis, or needling procedures. Conjunctival advancement surgery was performed to cover the exposed device. After the sufficient dissection of scar tissue surrounding the PFM and the reapproximation of the conjunctiva, the device was successfully covered. Postoperatively, the filtration bleb remained formed, and the intraocular pressure (IOP) was controlled. No recurrence of device exposure was observed after 18 months of follow-up. Although PFM device exposure is a rare complication, it requires prompt surgical intervention to prevent infection and maintain IOP control. Conjunctival advancement surgery is an effective treatment option that allows for the repair of the exposure while preserving the filtration function of the device.

Preserflo MicroShunt versus Trabeculectomy: Efficacy and Surgical Success within a Heterogenous Patient Cohort

To compare success rates of trabeculectomy (TE) and Preserflo MicroShunt (PMS) in heterogenous glaucoma cohorts with regards to different pre- and postoperative therapeutic regimens. Data of 187 glaucoma patients who either received TE (73 eyes) or PMS implantation (114 eyes) between January 2018 and December 2022 were retrospectively evaluated. Surgical success and failure rates were analyzed within six months of follow-up. Intraocular pressure (IOP) development over the course of follow-up was compared between both groups. Tertiary outcome measures were best-corrected visual acuity (BCVA), number and type of medications, frequency of postoperative complications and revision surgeries. Outcome measures underwent additional assessment based on subgroup categorizations, and failure time hazard ratios were computed. The success rates were comparable between both procedures (TE: 54.1%, PMS: 60.0%; p = 0.17). Both procedures showed significant IOP reduction (p < 0.01); however, overall IOP reduction was greater in the TE group than in the PMS group (TE: Reduction by 12 mmHg (188.9%), PMS: Reduction by 7 mmHg (51.3%); p = 0.01). The number of topical medications decreased significantly in both groups over the course of follow-up (TE: 4 to 0, PMS: 3 to 0; p < 0.01). While the number of complications and revision surgeries were similar in both groups, the time interval until the first revision surgery within the TE group was significantly shorter (TE: 13.5 d, PMS: 163 d; p = 0.01) than within the PMS group. No difference could be detected between TE and PMS with regard to the follow-up regimen. In particular, there was no significant difference in the need for 5-floururacil injections postoperatively (p = 0.29). Less invasive glaucoma surgery with the PMS appeared comparable to the TE within a heterogenous glaucoma cohort with regards to IOP development and freedom from medication.

PRESERFLO MicroShunt in Severe Myopia: A Case Report and Review of the Literature

The PRESERFLO™ MicroShunt (MP; Santen Inc., Osaka, Japan) is a minimally invasive bleb surgery (MIBS) manufactured to treat primary open-angle glaucoma (POAG), with lower postoperative adverse effects than with conventional filtering surgeries. We describe here the case study of a 58-year-old woman who presented with bilateral severe myopia with bilateral advanced POAG and unreached target pressure under quadritherapy, who was successfully managed by PM surgery. A review of the literature completes our observation. At presentation, the patient had a spherical equivalent of - 7.50 RE and - 7.75 LE with an IOP of 22 mmHg right and left eye (RLE) under quadritherapy, and with severe bilateral visual field loss, including scotomas within the central 5°. The patient presented with systemic hypertension treated with an antihypertensive drug. Two selective laser trabeculoplasties (SLT), performed 3 months apart, were first tried on the LE, without any change in IOP at 2 months. After considering the high risk of postoperative complications, a PM operation was proposed, with a targeted IOP in the mid-fifteens RLE. The patient's eyes underwent PM surgery with mitomycin C (MMC) MMC0.2 mg/mL for 3 minutes without any complications. The LE required 2 consecutive needlings with 1 mL MMC0.2 mg/mL. At 24 months after surgery, the two eyes gave successful results without the need for any additional medical therapy, and with well-functioning conjunctival blebs. The PM was an effective alternative to the gold standard trabeculectomy in our severely myopic patient. A comparative study between conventional filtering operations and this MIBS in highly myopic patients would confirm our observation.

Glaucoma surgical procedures under development

PURPOSE OF REVIEW

Rapid innovation in glaucoma surgery is expanding surgical options in the angle, subconjunctival space, and supraciliary space.

RECENT FINDINGS

Advancements in glaucoma surgery make it possible for surgeons to provide treatments with less risk. In particular, new devices and lasers are available for minimally invasive glaucoma surgeries. There are also new implants and techniques for bleb-forming glaucoma surgery.

SUMMARY

As glaucoma surgeons have access to an increasing number of procedures, devices, and treatments, it is important for evidence to drive decision-making.

Comparing the safety and efficacy of Preserflo Microshunt implantation and trabeculectomy for glaucoma: A systematic review and meta-analysis

To compare the safety and efficacy of the Preserflo Microshunt with trabeculectomy in the treatment of patients with glaucoma. A systematic review and meta-analysis was conducted. The primary outcome measures recorded as a measure of efficacy of the interventions were intra-ocular pressure (IOP) at final follow-up and IOP reduction (IOPR). Secondary outcomes recorded to measure efficacy were reduction in the number of glaucoma medications and reinterventions. To assess safety profile, the proportions of patients with post-operative complications were recorded. Seven articles were included in this study. A total of 1353 eyes were included in this review (Preserflo: 812, trabeculectomy: 541). Post-operative IOP (mean difference [MD] = 0.78 [0.66, 0.90], p < 0.001) results are significantly lower for trabeculectomy than Preserflo. The IOPR (MD = -1.20 [-2.30, -0.09], p = 0.034) results significantly favour trabeculectomy over Preserflo Microshunt. The reduction in topical glaucoma medications (MD = -0.32 [-0.58, -0.07], p = 0.014) is significantly higher for trabeculectomy. There is no statistically significant difference in levels of hypotony (risk ratio [RR] = -0.05 [-0.47, 0.37], p = 0.806), choroidal effusion/detachment (RR = -0.12 [-0.42, 0.19], p = 0.444), hyphaema (RR = 0.20 [-0.11, 0.51], p = 0.216) and flat anterior chamber (RR = 0.49 [-1.02, 0.03], p = 0.066). There are significantly more bleb-related complications in the trabeculectomy groups than Preserflo groups (RR = -0.63 [-1.01, -0.24], p = 0.001). There were statistically more reinterventions required in the trabeculectomy groups than Preserflo groups (RR = -0.48 [-0.65, -0.30], p < 0.001). Compared to trabeculectomy, the Preserflo Microshunt is not as effective in lowering intra-ocular pressure, has a similar safety profile and has a lower reintervention rate. Further research is required given the lack of randomised controlled trials within this study and resulting low strength of evidence.

PRESERFLO MicroShunt implantation versus trabeculectomy for primary open-angle glaucoma: a two-year follow-up study

BACKGROUND

To compare the intermediate-term efficacy of PRESERFLO (PF) MicroShunt implantation with trabeculectomy (TE) in patients with primary open-angle glaucoma, focusing on longitudinal changes of functional and structural parameters.

METHODS

This retrospective comparative study included 104 eyes of 104 patients who underwent TE and 83 eyes of 83 patients that underwent PF implantation between January 2019 and December 2020, with a minimum follow-up of two years. Baseline and postoperative intraocular pressure (IOP), number of IOP-lowering medications, visual field mean defect (MD) and peripapillary retinal nerve fibre layer (RNFL) thickness measured using optical coherence tomography were assessed and compared between groups.

RESULTS

Baseline characteristics (age, sex, IOP, number of IOP-lowering medications, MD, RNFL thickness) were comparable between the two groups (all P > 0.05). During the two-year of follow-up, mean IOP decreased from 24.09 ± 1.15 mmHg and 21.67 ± 0.77 mmHg to 11.37 ± 1.13 mmHg (P < 0.001) and 15.50 ± 1.54 mmHg (P = 0.028), and the mean number of IOP-lowering medications decreased from 3.25 ± 0.14 and 3.51 ± 0.14 to 0.53 ± 0.14 (P < 0.001) and 1.06 ± 0.43 (P < 0.001) in the TE and PF groups, respectively. MD remained stable [- 11.54 ± 0.93 dB and - 11.17 ± 1.66 to - 10.67 ± 0.91 dB (P = 0.226) and - 10.40 ± 4.75 dB (P = 0.628) in the TE and PF groups, respectively] but RNFL thickness decreased continuously during follow-up [62.79 ± 1.94 µm and 62.62 ± 2.05 µm to 57.41 ± 1.81 µm (P < 0.001) and 60.22 ± 1.98 µm (P = 0.182) in the TE and PF groups, respectively].

CONCLUSION

PF implantation is comparably effective in the intermediate term in lowering IOP and reducing the use of IOP-lowering medications over a two-year follow-up period. Although visual field defects were stable, RNFL continued to decrease during postoperative follow-up.

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.

Dislocation of the PreserFlo MicroShunt During a Postsurgical Needling Procedure

We report a case of PreserFlo MicroShunt (PFM) dislocation following a postsurgical needling procedure. A 58-year-old woman underwent PFM implantation for exfoliation glaucoma in her left eye (OS). There were no intraoperative complications. Preoperatively, her best-corrected visual acuity (BCVA) was 0.6, and her intraocular pressure (IOP) was 25 mmHg with three antiglaucoma medications in the OS. On postoperative day 21, the IOP was 21 mmHg OS, and the filtration bleb had shrunk. A needling procedure was performed using a sharp 26-gauge needle to lower the IOP. On postoperative day 29, the BCVA was 0.02, and the IOP was 60 mmHg OS. Gonioscopy revealed no device tip in the anterior chamber, and peripheral anterior synechia was observed at the site of PFM insertion. Anterior segment optical coherence tomography showed a dislocated device in the subconjunctival space. On postoperative day 35, the dislocated PFM was removed, and a new device was inserted. Following the reoperation, no further complications were observed, and bleb formation was obtained. In conclusion, like other glaucoma filtering surgeries, PFM may require postsurgical needling procedures. Needling procedures may cause PFM dislocation and IOP rise, resulting in the requirement for further IOP-reducing procedures.

[Comparison of new and old procedures in glaucoma surgery : Trabeculectomy, Preserflo and XEN]

Glaucoma is one of the most frequent causes of irreversible blindness worldwide. The main risk factor of the disease is an individually too high intraocular pressure and pressure reduction is still the only established treatment. If conservative pressure reduction and adherence are insufficient, and if the patient is unable to tolerate conservative treatment, surgical procedures become necessary. There are nowadays more than a dozen different surgical procedures for lowering the pressure. This article presents and discusses the procedures that have a subconjunctival pre-equatorial drainage in common. These include trabeculectomy, the XEN-gel implant and the Preserflo microshunt.