CONCLUSIONS: This systematic review and meta-analysis concludes that the PreserFlo Microshunt glaucoma drainage device significantly reduces intraocular pressure in primary open angle glaucoma patients at 12 months postinsertion.
OBJECTIVE: A systematic review and meta-analysis on the effect of the PRESERFLO MicroShunt (PF-MS) on intraocular pressure (IOP) at 12 months has been conducted.
METHODS: The PubMed/MEDLINE, Embase, CENTRAL, Google Scholar, Scopus, and Web of Science databases were searched. Inclusion criteria required a diagnosis of open angle glaucoma, PF-MS insertion, and examination of IOP over time. Meta-analyses were conducted on the primary outcome of IOP and the secondary outcome of glaucoma medication regime. Adverse events were also noted.
RESULTS: Fourteen studies were identified for inclusion in the meta-analyses, of which none had a high risk of bias. The meta-analyses found a significant mean reduction in IOP of 9.07 mm Hg (95% CI: 7.88-10.25; P <0.0001) and a significant mean reduction in mean glaucoma medication requirement of 2.37 medications (95% CI: 2.15-2.60; P <0.0001). Hypotony and hyphaema are common early complications.
CONCLUSIONS: The PF-MS device significantly reduced both IOP and glaucoma medication requirement at 12 months postinsertion in individuals with open angle glaucoma without a significant adverse event burden. Further research is required to determine the economic and environmental effects of widely implementing the PF-MS device into clinical practice.

OBJECTIVE: The effectiveness of mitomycin C (MMC) in trabeculectomy has long been established. The aim of this review is to evaluate the efficacy and safety of adjunctive agents in tube shunt drainage device surgery for glaucoma or ocular hypertension, since controversy still exists regarding their benefit.
METHODS: We searched CENTRAL, PubMed, Embase, Web of Science, Scopus, and BASE for RCTs, which have used adjuvant antimetabolites-either MMC or 5-Fluorouracil (5-FU)-and/or anti-vascular endothelial growth factors (anti-VEGF) agents. The main outcome was IOP reduction at 12 months.
RESULTS: Ten studies met our inclusion criteria. Nine used the Ahmed Glaucoma Valve (AGV) implant, while the double-plate Molteno implant was used in one study. Four studies used MMC. The remaining six studies used an anti-VEGF drug - either bevacizumab, ranibizumab or conbercept. Only one MMC-study reported a significant difference in the IOP reduction between groups at 12 months, favouring the MMC group (55% and 51%; p < 0.01). A significant difference was also reported by two out of five bevacizumab-studies, both favouring the bevacizumab group (55% and 51%, p < 0.05; 58% and 27%, p < 0.05), with the highest benefit seen in neovascular glaucoma cases, especially when panretinal photocoagulation (PRP) was also used. Neither ranibizumab nor conbercept were found to produce significant differences between groups regarding IOP reduction.
CONCLUSIONS: There is no high-quality evidence to support the use of MMC in tube shunt surgery. As for anti-VEGF agents, specifically bevacizumab, significant benefit seems to exist in neovascular glaucoma patients, especially if combined with PRP.

Implantation of glaucoma drainage devices is a valuable therapeutic option, particularly in children with glaucoma refractory to primary surgical treatment. Glaucoma drainage devices are typically used when conjunctival scarring hampers filtration surgery or prior angle procedures are not effective in controlling intraocular pressure. Despite known complications, the use of glaucoma drainage devices in children has increased in recent years, even as the primary surgical option. In this review, we evaluate the results of recent studies involving the implantation of glaucoma drainage devices in children, discussing new advances, and comparing the success rates and complications of different devices.

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.

UNASSIGNED: This study assesses the effectiveness and safety of using Ologen implants (Aeon Astron Europe BV, Leiden, The Netherlands) as an adjunctive therapy in childhood glaucoma surgeries.
UNASSIGNED: We systematically reviewed the existing literature across various electronic databases to examine the effectiveness and safety of Ologen implants in childhood glaucoma surgeries.
UNASSIGNED: Our analysis encompassed 14 studies on the use of Ologen implants in childhood glaucoma. Among these, seven were prospective, five were retrospective, and two did not specify their study design. Success rates varied depending on the type of surgery and the included childhood glaucoma subtype. The success rates for Ologen implants-augmented surgeries were as follows: 33.3-70% for trabeculectomy, 50-81% for combined trabeculotomy-trabeculectomy procedure, 33%-87% for glaucoma drainage device, and 60% in deep sclerectomy.
UNASSIGNED: Ologen implant has a potential role in mitigating postoperative fibrosis and enhancing success rates in various childhood glaucoma surgeries. However, the existing literature is limited. Future comparative prospective studies with larger cohorts are needed.

The surgical management of glaucoma has been enriched in recent years by the arrival of new surgical techniques as a group known as MIGS (minimally invasive glaucoma surgery). The objective of these new techniques is to reduce intraocular pressure (IOP) while limiting the risk of complications of conventional filtering surgery and allowing faster visual recovery. MIGS can be classified into three main categories depending on the route used to promote the outflow of aqueous humor: the trabecular route, the suprachoroidal route and the subconjunctival route. MIGS using the subconjunctival route are also called minimally invasive bleb surgery (MIBS). These new techniques do not replace conventional filtering surgery, which remains the gold standard technique, but now offer new alternatives for the surgical management of glaucoma patients in combination with cataract surgery or as stand-alone procedures.

Glaucoma is a progressive optic neuropathy in the eye, which is a leading cause of irreversible blindness worldwide and currently affects over 70 million individuals. Clinically, intraocular pressure (IOP) reduction is the only proven treatment to halt the progression of glaucoma. Microfluidic devices such as glaucoma drainage devices (GDDs) and minimally invasive glaucoma surgery (MIGS) devices are routinely used by ophthalmologists to manage elevated IOP, by creating an artificial pathway for the over-accumulated aqueous humor (AH) in a glaucomatous eye, when the natural pathways are severely blocked. Herein, a detailed modelling and analysis of both the natural microfluidic pathways of the AH in the eye and artificial microfluidic pathways formed additionally by the various glaucoma implants are conducted to provide an insight into the causes of the IOP abnormality and the improvement schemes of current implant designs. The mechanisms of representative glaucoma implants have been critically reviewed from the perspective of microfluidics, and we have categorized the current implants into four groups according to the targeted drainage sites of the AH, namely Schlemm\'s canal, suprachoroidal space, subconjunctival space, and ocular surface. In addition, we propose to divide the development and evolution of glaucoma implant designs into three technological waves, which include microtube (1st), microvalve (2nd) and microsystem (3rd). With the emerging trends of minimal invasiveness and artificial intelligence in the development of medical implants, we envision that a comprehensive glaucoma treatment microsystem is on the horizon, which is featured with active and wireless control of IOP, real-time continuous monitoring of IOP and aqueous rate, etc. The current review could potentially cast light on the unmatched needs, challenges, and future directions of the microfluidic structural and functional designs of glaucoma implants, which would enable an enhanced safety profile, reduced complications, increased efficacy of lowering IOP and reduced IOP fluctuations, closed-loop and on-demand control of IOP, etc.

BACKGROUND: The iStent (Glaukos Corporation; Laguna Hills, CA, USA) is one of the minimally invasive glaucoma devices. It can be inserted at the time of phacoemulsification or as a stand-alone procedure to lower the intraocular pressure (IOP).
OBJECTIVE: Our aim was to conduct a systematic review and meta-analysis comparing the effect of iStent insertion at the time of phacoemulsification with phacoemulsification alone in patients with ocular hypertension or open-angle glaucoma.
METHODS: We searched EMBASE, MEDLINE (OVID and PubMed), CINAHL, and Cochrane Library for articles published between 2008 and June 2022 (PRISMA 2020 for the checklist). Studies comparing the IOP-lowering effect of iStent with phacoemulsification versus phacoemulsification alone were included. The endpoints were IOP reduction (IOPR) and the mean reduction in the number of glaucoma drops. A quality-effects model was used to compare both surgical groups.
RESULTS: Ten studies were included, reporting on 1,453 eyes. Eight hundred fifty three eyes had the combined iStent and phacoemulsification, and 600 eyes underwent phacoemulsification alone. IOPR was higher in the combined surgery at of 4.7 ± 2 mm Hg compared to 2.8 ± 1.9 mm Hg in phacoemulsification alone. A greater decrease in postoperative eye drops was noted in the combined group having a decrease of 1.2 ± 0.3 eye drops versus of 0.6 ± 0.6 drops in isolated phacoemulsification. The quality effect model showed an IOPR weighted mean difference (WMD) of 1.22 mm Hg (confidence interval [CI]: [-0.43, 2.87]; Q = 315.64; p < 0.01; I2 = 97%) and decreased eye drops WMD 0.42 drops (CI: [0.22, 0.62]; Q = 42.6; p < 0.01; I2 = 84%) between both surgical groups. Subgroup analysis shows that the new generation iStent may be more effective in reducing IOP.
CONCLUSIONS: iStent has a synergetic effect with phacoemulsification. The reduction of IOP and glaucoma eye drops was higher when iStent is combined with phacoemulsification compared with isolated phacoemulsification.

To compare the efficacy and safety of tube shunt implantation with trabeculectomy in the treatment of patients with glaucoma.
A systematic literature search was performed for studies comparing tube with trabeculectomy in patients with glaucoma (final search date: 27 February 2022). Comparisons between tube and trabeculectomy were grouped by the type of tube (Ahmed, Baerveldt, Ex-PRESS and XEN). The primary endpoints included intraocular pressure (IOP), IOP reduction (IOPR), IOPR percentage (IOPR%), complete success rate (CSR), qualified success rate (QSR) and adverse events (AEs).
Forty-nine studies were included in this meta-analysis and presented data for 3795 eyes (Ahmed: 670, Baerveldt: 561, Ex-PRESS: 473, XEN: 199, trabeculectomy: 1892). Ahmed and Ex-PRESS were similar to trabeculectomy in terms of IOP outcomes and success rate (Ahmed vs trabeculectomy: IOPR%: mean difference (MD)=1.34 (-5.35, 8.02), p=0.69; Ex-PRESS vs trabeculectomy: IOPR%: MD=0.12 (-3.07, 3.31), p=0.94). The IOP outcomes for Baerveldt were worse than those for trabeculectomy (IOPR%: MD=-7.51 (-10.68, -4.35), p<0.00001), but the QSR was higher. No significant difference was shown for the CSR. XEN was worse than trabeculectomy in terms of IOP outcomes (IOPR%: MD=-7.87 (-13.55, -2.18), p=0.007), while the success rate was similar. Ahmed and Ex-PRESS had a lower incidence of AEs than trabeculectomy. Baerveldt had a lower incidence of bleb leakage/wound leakage, hyphaema and hypotonic maculopathy than trabeculectomy but a higher incidence of concurrent cataracts, diplopia/strabismus and tube erosion. The incidence of AEs was similar for the XEN and trabeculectomy procedures.
Compared with trabeculectomy, both Ahmed and Ex-PRESS appear to be associated with similar ocular hypotensive effects and lower incidences of AEs. However, Baerveldt and XEN cannot achieve sufficient reductions in IOP outcomes similar to those of trabeculectomy.
CRD42021257852.

The use of microinvasive invasive glaucoma surgery (MIGS) in the treatment of glaucoma has increased exponentially over the last 10 years. However, practice patterns vary widely given the relative newness of these technologies. Some surgeons perform two or more MIGS simultaneously, such as those that target aqueous production and those that target aqueous outflow. These combined MIGS (cMIGS) may result in lower intraocular pressure (IOP) and reduced medication burden as compared to single MIGS (sMIGS). Current evidence suggests some cMIGS are more effective in reducing medication burden for at least 12 months versus sMIGS. This review focuses on the current evidence related to the efficacy of cMIGS as well as novel combinations of standalone MIGS, limitations of the current literature, and future directions for research.