Comparative Cost-effectiveness of Trabeculectomy versus MicroShunt in the US Medicare System

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.

European Glaucoma Society - A guide on surgical innovation for glaucoma

PROLOGUE: Glaucoma surgery has been, for many decades now, dominated by the universal gold standard which is trabeculectomy augmented with antimetabolites. Tubes also came into the scene to complement what we use to call conventional or traditional glaucoma surgery. More recently we experienced a changing glaucoma surgery environment with the "advent" of what we have become used to calling Minimally Invasive Glaucoma Surgery (MIGS). What is the unmet need, what is the gap that these newcomers aim to fill? Hippocrates taught us "bring benefit, not harm" and new glaucoma techniques and devices aim to provide safer surgery compared to conventional surgery. For the patient, but also for the clinician, safety is important. Is more safety achieved with new glaucoma surgery and, if so, is it associated with better, equivalent, or worse efficacy? Is new glaucoma surgery intended to replace conventional surgery or to complement it as an 'add-on' to what clinicians already have in their hands to manage glaucoma? Which surgery should be chosen for which patient? What are the options? Are they equivalent? These are too many questions for the clinician! What are the answers to the questions? What is the evidence to support answers? Do we need more evidence and how can we produce high-quality evidence? This EGS Guide explores the changing and challenging glaucoma surgery environment aiming to provide answers to these questions. The EGS uses four words to highlight a continuum: Innovation, Education, Communication, and Implementation. Translating innovation to successful implementation is crucially important and requires high-quality evidence to ensure steps forward to a positive impact on health care when it comes to implementation. The vision of EGS is to provide the best possible well-being and minimal glaucomainduced visual disability in individuals with glaucoma within an affordable healthcare system. In this regard, assessing the changes in glaucoma surgery is a pivotal contribution to better care. As mentioned, this Guide aims to provide answers to the crucial questions above. However, every clinician is aware that answers may differ for every person: an individualised approach is needed. Therefore, there will be no uniform answer for all situations and all patients. Clinicians would need, through the clinical method and possibly some algorithm, to reach answers and decisions at the individual level. In this regard, evidence is needed to support clinicians to make decisions. Of key importance in this Guide is to provide an overview of existing evidence on glaucoma surgery and specifically on recent innovations and novel devices, but also to set standards in surgical design and reporting for future studies on glaucoma surgical innovation. Designing studies in surgery is particularly challenging because of many subtle variations inherent to surgery and hence multiple factors involved in the outcome, but even more because one needs to define carefully outcomes relevant to the research question but also to the future translation into clinical practice. In addition this Guide aims to provide clinical recommendations on novel procedures already in use when insufficient evidence exists. EGS has a long tradition to provide guidance to the ophthalmic community in Europe and worldwide through the EGS Guidelines (now in their 5th Edition). The EGS leadership recognized that the changing environment in glaucoma surgery currently represents a major challenge for the clinician, needing specific guidance. Therefore, the decision was made to issue this Guide on Glaucoma Surgery in order to help clinicians to make appropriate decisions for their patients and also to provide the framework and guidance for researchers to improve the quality of evidence in future studies. Ultimately this Guide will support better Glaucoma Care in accordance with EGS's Vision and Mission. Fotis Topouzis EGS President

IOP-lowering and drug-sparing effects of trabectome surgery with or without cyclodialysis ab interno

PURPOSE

To compare the postoperative intraocular pressure (IOP) after ab interno trabeculectomy (AIT; trabectome surgery) alone or combined with cyclodialysis ab interno (AITC).

PATIENTS AND METHODS

Forty-three eyes with insufficiently controlled open-angle glaucoma were included in this consecutive case series. All eyes received AIT, combined with phacoemulsification and IOL-implantation in phakic instances, with or without additional cyclodialysis ab interno. Postoperative visual acuity, IOP, number of IOP-lowering medications and complications were registered over 12 months.

RESULTS

A total of 19 eyes (14 patients) received AIT and 24 (19 patients) received AITC. Both groups were comparable for baseline IOP (AIT: 19.7 ± 8.2 mmHg; AITC: 19.4 ± 6.8 mmHg; p = 0.96), there was a comparable IOP reduction after 6 months (AIT: - 3.8 ± 12.3, median (interquartile range (IQR)): - 3.8 (- 7.8-4.8) mmHg; AITC: - 4.9 ± 8.3, median (IQR): - 2.0 (- 10.8-2.0) mmHg; p = 0.95) and 12 months (AIT: - 4.3 ± 6.6, median (IQR): - 4.0 (- 8.0 to - 1.0) mmHg; AITC: - 3.7 ± 6.7, median (IQR): - 1.5 (- 5.5 to - 0.5) mmHg; p = 0.49). While final visual acuity was similar between the groups, they differed regarding topical IOP-lowering medications (baseline: AIT 2.9 ± 1.2 and AITC 2.9 ± 1.2; 1 year after surgery: AIT 2.6 ± 1.5 (p = 0.16) and AITC 1.3 ± 1.3; p < 0.001)). Depending on the definition, a complete or qualified success of 33.4-45.8% was achieved in AITC compared to 15.8-21.1% in AIT.

CONCLUSION

The additional suprachoroidal outflow when AIT is combined with cyclodialysis ab interno (AITC) seems to result in an additional drug sparing effect for at least 1 year without critical safety signals. Thus, AITC might be further investigated prospectively prior to advocating its use in routine minimally invasive glaucoma surgery.

Cost-utility analysis of commonly used anti-glaucoma interventions for mild-to-moderate primary open-angle glaucoma patients in rural and urban China

OBJECTIVE

An increasing number of studies have explored the clinical effects of antiglaucoma surgical procedures; however, economic evidence was scarce. We aimed to compare the cost-effectiveness between maximal medical treatment (MMT) and commonly used surgical procedures (trabeculectomy, Ahmed glaucoma valve implantation, gonioscopy-assisted transluminal trabeculotomy and ab interno canaloplasty).

DESIGN AND SETTING

A Markov model study.

PARTICIPANTS

A hypothetical cohort of 100 000 patients with mild-to-moderate primary open-angle glaucoma (POAG).

OUTCOMES

Data were obtained from public sources. The main outcomes were incremental cost-utility ratios (ICURs) using quality-adjusted life-years (QALYs). Sensitivity analyses were conducted to verify the robustness and sensitivity of base-case results.

MAIN RESULTS

Both cumulative costs and QALYs gained from surgical procedures (US$6045-US$13 598, 3.33-6.05 QALYs) were higher than those from MMT (US$3117-US$6458, 3.14-5.66 QALYs). Compared with MMT, all surgical procedures satisfied the cost-effectiveness threshold (lower than US$30 501 and US$41 568 per QALY gained in rural and urban settings, respectively). During the 5-year period, trabeculectomy produced the lowest ICUR (US$21 462 and US$15 242 per QALY gained in rural and urban settings, respectively). During the 10-year-follow-up, trabeculectomy still produced the lowest ICUR (US$13 379 per QALY gained) in urban setting; however, gonioscopy-assisted transluminal trabeculotomy (US$19 619 per QALY gained) and ab interno canaloplasty (US$18 003 per QALY gained) produced lower ICURs than trabeculectomy (US$19 675 per QALY gained) in rural areas. Base-case results were most sensitive to the utilities and costs of initial treatment and maintenance.

CONCLUSIONS

The long-term cost-effectiveness of commonly used surgical procedures could be better than the short-term cost-effectiveness for mild-to-moderate POAG patients in China. Health economic studies, supported by more rigorous structured real-world data, are needed to assess their everyday cost-effectiveness.

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

PURPOSE

Clinical evaluation and cost analysis of mitomycin-C-augmented PreserFlo MicroShunt versus trabeculectomy.

DESIGN

Retrospective cohort study across 3 teaching hospitals.

PARTICIPANTS

A total of 134 consecutive eyes of 129 patients (70 undergoing MicroShunt, 64 trabeculectomy).

METHODS

Primary and secondary glaucoma cases with uncontrolled intraocular pressure (IOP) were included. Neovascular glaucoma and surgery combined with cataract extraction were excluded. The cost analysis used results from the clinical study to estimate operative costs (equipment and staff costs) and postoperative costs (follow-up visits, nonglaucoma medications, and postoperative procedures) per eye for PreserFlo and trabeculectomy.

MAIN OUTCOME MEASURES

The primary clinical outcome measure was surgical failure (defined as IOP > 21 mmHg or < 20% reduction from baseline, IOP ≤ 5 mmHg, reoperation, or loss of light perception) or qualified and complete success (with or without medication) at 18 months. Secondary measures were IOP, glaucoma medications, visual acuity, mean deviation, time to cessation of steroid drops, complications, surgical time, follow-up visits, postoperative interventions, and reoperations. The cost analysis evaluated costs of PreserFlo compared with trabeculectomy.

RESULTS

Baseline characteristics were similar, except for more non-White patients in the trabeculectomy group (51% Black and Asian vs. 32% MicroShunt, P = 0.02) and more cases with prior ab externo glaucoma surgery in the MicroShunt group (19% vs. 3% in the trabeculectomy group, P = 0.004). Overall, 59% of eyes had primary open-angle glaucoma. Mean follow-up was 19.9 months for both groups. At 18 months, surgical failure was 25% for MicroShunt compared with 35% for trabeculectomy (P = 0.18). Failure in MicroShunt cases was due to inadequate IOP reduction (84%) or reoperation for glaucoma (16%). Failure in trabeculectomy cases was due to inadequate IOP reduction (58%), persistent hypotony (29%), or reoperation for glaucoma (13%). Combined blebitis and endophthalmitis rate was 1.4% for MicroShunt and 3.1% for trabeculectomy. Cost analysis showed a savings of £245 to £566 per eye in the MicroShunt group, driven mostly by reduced postoperative procedures and follow-up visits. This is in contrast to prior randomized controlled trial data reporting the incremental cost of $2058 of PreserFlo over trabeculectomy.

CONCLUSIONS

Our experience of introducing PreserFlo MicroShunt surgery showed it was safer than trabeculectomy and is a cost-saving and effective option that offers potential to free up highly limited National Health Service resources.

FINANCIAL DISCLOSURE(S)

Proprietary or commercial disclosure may be found after the references.

Bleb geometry and morphology after Preserflo Microshunt surgery: Risk factors for surgical failure

PURPOSE

To investigate the possible risk factors for treatment failure in patients who had undergone Preserflo Microshunt (PMS) implantation, using anterior-segment optical coherence tomography (AS-OCT) to analyze the internal structures of the bleb.

METHODS

The PMS blebs of 54 patients were evaluated with AS-OCT. A mathematical model was used to calculate the total filtering surface of the episcleral fluid cavity (EFC) and the hydraulic conductivity (HC) of the bleb wall. Complete and qualified success were defined as IOP between 6 and 17 mmHg with or without glaucoma medication. The relation between baseline characteristics and probability of bleb success was analyzed by bivariate and multivariate logistic regression. The main outcome measures were mean bleb wall thickness (BWT), reflectivity (BWR), HC, mean horizontal and vertical diameter and total filtering surface (TFS) of the EFC.

RESULTS

Blebs from 74% patients were considered as complete success and 26% as failure. BWR and BWT increased linearly up to the first year in both groups. BWR was higher in the group failure (p = 0.02) and BWT in the group success (p<0.001). EFC was wider and shorter in the success group (p = 0.009, p = 0.03). Higher TFS showed a negative correlation with IOP (r = -0.4, p = 0.002). Higher baseline IOP was associated with success of PMS by multivariate analysis (p = 0.01). Mean HC, 0.034 ± 0.008 (μL/min)/mm2/mmHg, was negatively correlated with bleb surface (r = -0.5, p<0.0001) and wall´s thickness (r = -0.3, p = 0.01).

CONCLUSIONS

AS-OCT revealed that successful PMS blebs could show either thick hyporreflective walls or wide filtering surfaces with thin capsules. A higher baseline IOP increased the probability of surgical success.

MicroShunt versus Trabeculectomy for Surgical Management of Glaucoma: A Retrospective Analysis

This case-control study aims to compare the efficacy, safety, and postoperative burden of MicroShunt versus trabeculectomy. The first consecutive cohort of MicroShunt procedures (n = 101) was matched to recent historical trabeculectomy procedures (n = 101) at two London hospital trusts. Primary endpoints included changes in intraocular pressure (IOP) and glaucoma medications. Secondary outcome measures included changes in retinal nerve fibre layer (RNFL) thickness, rates of complications, further theatre interventions, and the number of postoperative visits. From the baseline to Month-18, the median [interquartile range] IOP decreased from 22 [17–29] mmHg (on 4 [3–4] medications) to 15 [10–17] mmHg (on 0 [0–2] medications) and from 20 [16–28] mmHg (on 4 [3–4] medications) to 11 [10–13] mmHg (on 0 [0–0] medications) in the MicroShunt and trabeculectomy groups, respectively. IOP from Month-3 was significantly higher in the MicroShunt group (p = 0.006), with an increased number of medications from Month-12 (p = 0.024). There were greater RNFL thicknesses from Month-6 in the MicroShunt group (p = 0.005). The rates of complications were similar (p = 0.060) but with fewer interventions (p = 0.031) and postoperative visits (p = 0.001) in the MicroShunt group. Therefore, MicroShunt has inferior efficacy to trabeculectomy in lowering IOP and medications but provides a better safety profile and postoperative burden and may delay RNFL loss.