Abstract
The iStent series constitutes a range of trabecular bypass minimally invasive glaucoma surgery (MIGS) devices, which offers intraocular pressure (IOP) reduction with favourable safety profiles, in patients with open-angle glaucoma (OAG). Having undergone significant evolution since its initial US FDA-approval in 2012, successive generations address previous limitations, while enhancing IOP-lowering efficacy through device and delivery system design iterations. Longer-term and real-world iStent data demonstrate the durability of IOP- and medication-lowering outcomes with minimal complications, while preliminary studies across a wider spectrum of glaucoma subtypes and severities provide limited evidence of successful outcomes beyond mild-to-moderate OAG, both with and without concomitant cataract surgery. Aqueous humour outflow assessment and novel intra-operative techniques may further facilitate more accurate and effective iStent positioning. Despite typically higher upfront costs, results from both cost-effectiveness and patient-reported outcome studies are encouraging. Combination MIGS with the iStent, leveraging on the multiple mechanisms of actions of various procedures, may provide greater IOP-lowering efficacy without compromising safety. With expanding clinical data and progressive enhancements, iStent technology is likely to remain a key component of the evolving MIGS landscape.
1 Introduction
Glaucoma, a progressive optic neuropathy with characteristic structural and functional visual field loss, is the most common cause of irreversible blindness worldwide (1, 2). Intraocular pressure (IOP), the only known modifiable risk factor to prevent disease progression, remains the target of glaucoma therapy (3).
Minimally invasive glaucoma surgery (MIGS) is gaining rapid traction globally, characterized by impressive safety profiles with minimal anatomical disruption and rapid recovery compared to traditional filtering surgeries (4). MIGS can be categorized into angle-based, suprachoroidal, and subconjunctival MIGS, based on their respective targeted sites of action (5).
Angle-based MIGS target the trabecular meshwork, identified as the site of greatest resistance to aqueous outflow in primary open angle glaucoma (POAG). They encompass trabecular-bypass stents [e.g., iStent series (Glaukos Corporation, Laguna Hills, CA, USA), Hydrus Microstent (Ivantis, Inc., Irvine, CA, USA) (6, 7)], trabecular excisional procedures [e.g., Kahook Dual Blade (New World Medical, Rancho Cucamonga, CA, USA), goniotomy, gonioscopy assisted transluminal trabeculotomy (GATT) (8, 9)] and canaloplasty procedures [e.g., iTrack microcatheter (Nova Eye Medical, Fremont, USA) (10)].
The iStent was the first MIGS implant to attain U.S. Food and Drug Administration (FDA) approval in 2012 (11). Today, the iStent series is used worldwide, and remains to date, the smallest FDA-approved implant in the human body (12). With an impressive safety profile, the iStent series has demonstrated successful reduction in IOP and medication burden while limiting disease progression in patients with mild-to-moderate OAG (13). Subsequent generations of the iStent (iStent inject, iStent inject W, iStent infinite) have been developed, with the stent design and implementation mechanism of each successive iteration addressing the limitations of its predecessor, while improving predictability of implantation and enhancing surgical efficacy.
This narrative review traces the evolution of iStent technology from its inception to the present day and examines five major themes of research and innovation over the past decade, summarized by Table 1.
Table 1
| Theme | Current evidence | Clinical implications | Areas of further research |
|---|---|---|---|
| Long-term outcomes |
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| Device design and technique |
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| Expanded Indications and predictors |
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| Cost- effectiveness and patient-reported outcomes |
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| Combination MIGS |
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Summary of key research and innovation themes in iStent technology over the past decade.
1.1 Methods
A systematic literature search across electronic databases (PubMed, Embase, and Web of Science) was conducted to identify peer-reviewed articles on the iStent, iStent inject and iStent infinite. The search covered publications from inception to 28 July 2025. Keywords included: “iStent,” “iStent inject,” “iStent infinite,” “trabecular micro-bypass,” “minimally invasive glaucoma surgery,” and “MIGS.” Boolean operators and MeSH terms were used where appropriate to maximize sensitivity. Inclusion criteria were: (1) original studies (including pilot studies, cohort studies, observational studies, randomized controlled trials and case reports or series) focused on the iStent, iStent inject or iStent infinite that (2) reported clinical outcomes, safety, efficacy, or device comparisons, and were (3) full-text articles published in English. Exclusion criteria were: (1) non-English language publications, (2) conference abstracts, letters, editorials, and (3) animal studies and in vitro research.
2 iStent technology—A story of evolution
2.1 1st generation iStent
The 1st generation iStent is a 1 mm single, heparin-coated, non-ferromagnetic titanium stent, designed with a self-trephining tipped snorkel and three retention arches, pre-loaded into a single-use injector. It works by incising and stenting the Schlemm’s canal (SC) to increase trabecular flow (14). It is offered concurrently with cataract surgery to patients with mild-to-moderate OAG, in the absence of angle abnormalities that may affect stent positioning (15). The pivotal trial published by Sameulson et al. in 2011 demonstrated that 66% of eyes with mild-to-moderate OAG which underwent combined iStent and cataract surgery achieved ≥20% IOP reduction at 1 year, compared to 48% of eyes which underwent cataract surgery alone, with similar rates of adverse events between both groups (15).
2.2 iStent inject and iStent inject W
The 2nd generation iStent inject, FDA-approved in 2018, features two shorter stents, measuring 360 μm in height and 230 μm in diameter, with a tapered head and a wide flange that sits in the anterior chamber. Both stents are placed 2–3 clock hours apart in the inferonasal quadrant of the angle, with their multidirectional design enabling them to deliver access to multiple collector channels and arcs of flow spanning up to 5–6 clock hours (6, 16). Indications for the iStent inject, offered in conjunction with cataract surgery to patients with mild-to-moderate OAG, were similar to its predecessor (17). The pivotal trial published by Sameulson et al. in 2019 found that after 2 years, 75.8% of eyes with mild-to-moderate OAG which underwent iStent inject combined with cataract surgery had ≥20% IOP reduction from baseline and 84% were drop-free; compared to 61.9 and 67%, respectively, in eyes which underwent standalone cataract surgery. Following studies replicated these outcomes, with an IOP reduction of 14.1–16% and a decrease of 0.61–1 medications reported 12–24 months after combined iStent inject and cataract surgery (18–20). The iStent inject has also been shown to result in greater IOP reduction compared to the 1st generation iStent (21–23). Safety-wise, a meta-analysis of 1,159 eyes reported that for both the iStent and iStent inject, post-operative IOP spike was most common, reported in 12/27 (44.4%) studies; followed by stent obstruction and malpositioning, reported in 8/27 (29.6%) and 7/27 (25.9%) studies, respectively (24). The iStent inject W, introduced in 2020, has a design almost identical to the iStent inject, except for a wider, 360 μm flange. The iStent inject W was designed to increase IOP and medication reductions compared to the iStent inject, while providing improved device positioning consistency, without significant differences in postoperative complications (25). Figure 1 depicts illustrations of the 1st generation iStent, iStent Inject and iStent inject W.
Figure 1
Illustrations of the (A) 1st generation iStent, (B) 2nd generation iStent inject, and (C) 3rd generation iStent inject W.
2.3 iStent infinite
The iStent infinite, FDA-approved in 2022, is the latest iteration of the iStent series. The multi-use delivery system is pre-loaded with three iStent inject W microstents, designed to create arcs of flow spanning up to 8 clock hours. Sarkisian et al. demonstrated that in 76.1% of OAG eyes uncontrolled by prior therapy, standalone iStent infinite implantation achieved ≥20% IOP reduction from baseline without increasing anti-glaucoma medications, with a mean IOP reduction of 5.9 mmHg, after 1 year (26). Interim analysis of the ongoing 24-month INTEGRITY study reported that at 6 months, the iStent infinite had a greater proportion of eyes achieving ≥20% IOP reduction from baseline, compared to the Hydrus microstent (78.2% vs. 65.0%), with lower complication rates (3.3% vs. 16.9%). “Improper stent placement” was observed in lower frequency with the iStent infinite in 1/91 eyes, compared to 7/89 eyes with the Hydrus Microstent (1.1% vs. 7.9%) (27).
3 Key research and innovation themes in iStent technology over the past decade
3.1 Longer-term and real-life surgical outcomes
Acknowledging that the FDA pivotal trials on iStent technology were pharmaceutical-sponsored (15, 26, 28), these studies reported positive 12 to 24-month surgical efficacy outcomes, with good overall safety profiles. However, notably, Araújo et al. highlighted that compared to real-world untreated POAG patients, subjects in the pivotal iStent inject trial appeared to have higher unmedicated baseline IOPs, in both the treatment and control arms (29). The Early Manifest Glaucoma Trial, for example, found that on population-based screening, the mean baseline IOP was only 20.6 mmHg among patients with newly diagnosed OAG (30). The higher baseline IOPs in the iStent FDA pivotal trial may have resulted in higher IOP reductions after standalone phacoemulsification in the control arm, with only a mild additional 1.6 mmHg IOP reduction and 0.4 medication reduction after 24 months, favouring combined iStent inject implantation and phacoemulsification. Questions have also been raised on whether the IOP-lowering effects of phacoemulsification, possibly inflated by the high baseline IOPs amongst recruited patients, may have driven the reduction in IOP after combined iStent inject implantation and phacoemulsification; and whether surgical efficacy would be longstanding, given that 38% of controlled POAG eyes may lose IOP control 1 year after cataract surgery (29, 31).
Later studies attempted to replicate the outcomes of the pivotal trials and explore the durability of iStent technology in real-world settings. Longer-term studies on combined iStent device implantation and phacoemulsification, examining outcomes at 5 years or more, have reported sustained medicated IOP and medication reductions of 12.7–39% and 0.5–1.74, respectively (32–36). Complication rates in all iStent studies have remained low – the most common being transient IOP spikes or hyphema (32–36). The 5-year follow-up safety study of the pivotal iStent inject study found no device-related adverse events or complications, with the rate of endothelial cell loss remaining similar to controls (37). Data from large real-world registries also appears consistent with findings from these studies. 24-month data from the Intelligent Research in Sight (IRIS®) Registry of 1,435 eyes which underwent combined iStent inject and phacoemulsification showed a moderate 22% reduction in medicated IOP and a reduction of 0.86 medications, in eyes that had a baseline IOP of >18 mmHg (38). Despite the encouraging data emerging from studies following the pivotal trials, the retrospective, unmasked design of these real-world studies may limit the strength of any causal inferences, requiring appropriate caution when interpreting their results. Longer-term safety data may also be needed to clarify the theoretical longer-term risks of peri-implant fibrosis within Schlemm’s canal and its impact on subsequent filtration surgery.
3.2 Optimization of device design and implantation technique
While the 1st generation iStent was delivered as a single device, studies have demonstrated a positive dose–response relationship between the number of stents and IOP-lowering efficacy. Belovay et al. attempted insertion of two or three 1st generation iStents combined with cataract surgery, and suggested multiple stents may result in greater IOP and medication reductions (39). Katz et al. (40) also reported that while the standalone implantation of one, two or three 1st generation iStents were all clinically effective, the implantation of more iStents was associated with incrementally greater IOP reductions and a reduced need to escalate medications after 42 months. These studies have supported the evolution of the single 1st generation iStent to current multi-stent iterations.
Design changes of the iStent in successive iterations were likely driven by the intention to improve safety and implantation predictability. Multiple studies on the 1st generation iStent reported early post-operative stent occlusion and malpositioning in 2.6–18% of eyes, with 4.5–11.3% requiring secondary surgical intervention (11, 15, 39, 41–49). The implantation technique for the 1st generation iStent – insertion at an angle, and then sliding sideways (50) – creates torque, which may increase risk of malpositioning (51). The iStent inject abandoned the snorkel design, employing instead a unidirectional entry path into the SC without torsion, hence likely reducing the risk of stent malpositioning initially faced by its predecessor (51).
Over-implantation, however, continued to be observed with the iStent inject. Gillman et al. reported that up to 45.7% of iStent inject devices could be entirely burrowed within the angle, as detected on anterior segment optical coherence tomography (OCT), which was greater than that suggested by gonioscopy (52). Corrective intra-operative techniques to manage over-implantation were subsequently described, via the extraction and reimplantation of over-implanted stents with the use of either the delivery system (53) or microforceps (54). The iStent inject W was subsequently developed, featuring a wider 360 μm flange to reduce the risk of over-implantation and to improve stent visualization (6). Its accompanying delivery system was also modified to improve intra-operative visualization and more consistent iStent delivery. The latest iStent infinite delivery system now allows for unlimited stent delivery attempts, further facilitating intra-operative rectification of malpositioned stents.
There has been growing recognition that malpositioned iStents may result in suboptimal IOP-lowering outcomes. Gillman et al. found that malpositioned stents resulted in greater distances between the head of the stent and the SC, smaller SC dilatations, and ultimately higher post-operative IOPs (52). Novel intra-operative techniques have been described to enhance and confirm the accuracy of iStent placement. Ang et al. suggested two intra-operative clinical signs to confirm accurate placement of the head of the iStent in the SC—blood reflux from the iStent lumen, elicited by gentle anterior chamber decompression; and the “Schlemm’s bidirectional fluid wave,” observed within the canal segments adjacent to the iStent after flushing with balanced salt solution (55). Sarohia et al. (56) described visualization of aqueous flow in the external vasculature near the iStent as an independent predictor of long-term IOP or medication reduction. The use of adjunct imaging, including intra- and post-operative OCT, for real-time and early post-operative evaluation of iStent positioning, has also been described (52, 57–59).
Apart from optimising the positioning of the stent, other studies sought to determine the optimal location to achieve the greatest improvement in aqueous outflow after iStent insertion—by examining localized changes in aqueous outflow, before and after iStent implantation. Bostan et al. (60) suggested that episcleral venous outflow could be used to evaluate iStent patency, and Fellman et al. (61) examined downstream patterns of episcleral venous fluid waves in-vivo as a measure of aqueous outflow, concluding that they were observed 2 clock hours adjacent to implanted iStents, favouring the inferonasal region. Lusthaus et al. (62, 63) found sectoral improvement of nasal and temporal aqueous outflow via in-vivo hemoglobin video imaging, following iStent implantation. These studies suggest segmental improvement of aqueous outflow following iStent insertion and may support the current common practice of iStent insertion into the nasal region of SC (64). Furthermore, ex-vivo studies using sequential aqueous angiography showed that placing trabecular micro-bypass stents into regions that were initially angiographically silent led to increased angiographic outflow signals (65), suggesting its potential use in pre-operative planning. However, these imaging techniques to visualize aqueous flow may not yet be feasible for routine clinical practice. Furthermore, with the current trajectory of advancements in iStent technology, it is possible that targeted stent placement may be less relevant, as the stents evolve to recruit a greater breadth of collector channels to create larger arcs of flow.
3.3 Expansion in indications and study into predictors of surgical success
While FDA-pivotal trials supported its initial use in conjunction with cataract surgery in mild-to-moderate POAG, the iStent inject has also been applied in several off-label indications such as standalone surgery and even in advanced POAG. A meta-analysis of 778 eyes that underwent standalone iStent or iStent inject implantation reported a weighted mean IOP reduction of 30.9% and a mean reduction of 1.19 medications at 36–60 months (66). Single-arm studies have further shown that standalone iStent infinite surgery is effective in moderate-to-advanced OAG uncontrolled by prior surgical or medical therapy (26).
Aside from POAG, iStent technology has also been applied in normal-tension glaucoma (NTG), primary angle-closure glaucoma (PACG) and secondary OAG. Modest IOP reductions of 0.7–2.31 mmHg in NTG eyes with 1–1.2 medication reductions 12 months after combined iStent and phacoemulsification have been reported, commensurate with the lower baseline IOPs in NTG, compared to POAG eyes (67–69). In PACG eyes, significant IOP and medication reductions of 27% and 11%, respectively, have been reported after combined iStent and phacoemulsification compared to matched standalone phacoemulsification controls, albeit with higher rates of complications such as iris occlusion (27%) and hyphema (18.9%) compared to that previously described in OAG eyes (70, 71). Clement et al. further reported sustained IOP and medication reductions 3 years following combined iStent and phacoemulsification, across multiple types of mild-to-advanced glaucoma, including pseudoexfoliative and pigmentary glaucoma (72). These findings may be of particular relevance in Asian populations, with a greater prevalence of NTG and PACG (73–75). However, current evidence describing the iStent’s effectiveness and safety profile outside of mild-to-moderate POAG mostly stem from small, single-centre, frequently uncontrolled studies. To date, the use of iStent in these settings is still considered off-label, with preliminary data suggesting weaker efficacy and higher complication rates. Larger, adequately powered randomized controlled trials are therefore required to define the role of the iStent in NTG, POAG, and advanced POAG, and to characterize its risk–benefit profile in these off-label indications.
Researchers have also explored pre-operative factors which may affect the success of iStent implantation and also better inform patient selection. Tan et al. reported that prior SLT was associated with an increased risk of failure after combined iStent inject and phacoemulsification compared to matched controls. The risk of failure, however, was significantly reduced if patients had higher baseline IOPs (76). Multivariate analysis conducted by Morita et al. found that a high pre-operative IOP was associated with a lower likelihood of surgical failure for both the iStent and iStent inject W, while the surgeon appeared to also be a significant factor in the iStent inject W group (77). A higher medication burden (≥3 types) prior to standalone iStent implantation has also been shown to increase risk of surgical failure (78). Laboratory studies have demonstrated that prolonged use of anti-glaucoma medications may cause trabecular meshwork damage, which may blunt the IOP response after iStent implantation (79, 80).
3.4 Cost-effectiveness, patient-reported outcome measures and quality of life outcomes
Further to the traditional efficacy outcomes of IOP and medication reduction, other outcome measures, including health-economic metrics, patient-reported outcomes and quality-of-life measures, have also been studied. Cost-utility analyses have found that while combined iStent inject and phacoemulsification resulted in higher total lifetime costs compared to standalone phacoemulsification, combined surgery demonstrated significantly higher gains in terms of the number of blind eyes avoided and quality-adjusted life years (QALYs) gained (81, 82). iStent inject with or without phacoemulsification also provided greater QALY gains compared to standard clinical care (i.e. topical medications or laser therapy) and yielded lower cumulative total healthcare costs (83–86). Overall, these studies demonstrate that the greater upfront cost of iStent technology may be offset by better long-term QALYs and greater healthcare cost savings. Furthermore, better ocular surface disease index scores have been reported, attributed to reduced medication burden and exposure (87–89). There was improved vision-related quality of life, convenience, and patient satisfaction, demonstrated in improved visual function questionnaire scores (87, 90).
3.5 Comparative outcomes between the iStent and other MIGS
Head-to-head comparative data between the iStent series with other MIGS remain limited and confined to small, industry-sponsored cohorts. Meta-analyses of current limited data suggest that the iStent had a more favourable safety profile but slightly lower IOP-lowering efficacy compared to other Schlemm’s canal-based procedures such as the Hydrus Microstent, albeit with small effect sizes (91–93), and similar IOP-lowering efficacy with Kahook Dual Blade Goniotomy (94). Sufficiently-powered, independently-funded randomized controlled trials directly comparing iStent technology with other MIGS remains a key unmet need – the results of these studies would aid significantly in more precise patient selection for each MIGS device and procedure.
3.6 Combination MIGS with the iStent
Further advances in MIGS have led to the conceptualisation of combined MIGS (cMIGS). Many involve combining iStent technology with other MIGS, with the intention of targeting multiple complementary IOP-lowering pathways simultaneously.
One such combination is the iStent inject and endoscopic cyclophotocoagulation (ECP) procedure, also known as ICE2, in which the iStent and ECP are combined with phacoemulsification. The iStent inject enhances trabecular outflow by bypassing the trabecular meshwork, while ECP reduces aqueous humour production by ablating ciliary processes, producing synergistic IOP-lowering effects that have been reported in prospective studies (95). Pantalon et al. found that ICE2 achieved a greater IOP reduction than combined phacoemulsification and iStent inject (35% vs. 21%), with a lower final mean IOP (13.05 vs. 14.09 mmHg) and medications (1.24 vs. 1.39) after 12 months (96). Safety profiles were similar in both groups. ICE2 has also been compared to both minimally invasive bleb surgery (MIBS) and combined MIGS in terms of efficacy and safety. Qidwai et al. found that eyes undergoing ICE2, PreserFlo Microshunt (Santen Pharmaceutical Co., Ltd., Osaka, Japan) and XEN45 gel stent (Allergan Inc., CA, USA) implantation had no statistically significant differences in IOP or number of anti-glaucoma medications after 24 months of follow-up, with only transient post-operative complications in all groups (97). Helwe et al. showed that while ECP and Kahook Dual Blade trabeculectomy (PEcK) achieved greater mean IOP (5 vs. 3.14 mmHg) and medication reductions (1.35 vs. 1.01) than the ICE2 group, early post-operative hyphema was more frequent in the PEcK group (98). These findings suggest that while ab interno trabeculectomy creates a larger outflow window, the incremental benefit over iStent implantation may be modest and accompanied by greater bleeding risk. Hence, ICE2 may offer an alternative for eyes requiring greater IOP reduction, while avoiding risks and complications associated with more invasive techniques such as trabeculectomy.
The iStent series has also been combined with ab-interno canaloplasty, which lowers IOP by enhancing circumferential outflow via viscodilation and 360° catheterization of the SC, while the iStent, a trabecular meshwork bypass device, synergistically allows aqueous to enter the dilated SC more efficiently. In a retrospective analysis, Heersink and Dovich reported that canaloplasty with the 1st generation iStent resulted in a larger mean IOP reduction at 6 months (2.9 ± 3.6 vs. 1.7 ± 3.1 mmHg), with more eyes achieving ≥20% IOP reduction and an IOP of <18 mmHg, compared to iStent implantation alone (46% vs. 35%), both with similar medication reductions (99). However, prospective data is still lacking for iStent combined with ab-interno canaloplasty.
Overall, early evidence suggests that cMIGS has potential to deliver incremental IOP-lowering efficacy compared to standalone iStent implantation. However, this additional benefit may be modest. Hence, patient selection is crucial and cMIGS should be reserved for eyes needing greater IOP reduction, justifying the additional procedural complexity and cost. At this time, current evidence remains limited and short-term, and the cost impact has not yet been well-evaluated.
4 Conclusion
In conclusion, iStent technology has undergone meaningful evolution since its introduction, with successive generations attempting to address previous limitations, while enhancing IOP-lowering efficacy through device and delivery system design iterations. Novel methods to facilitate and confirm optimal stent placement may improve surgical outcomes in addition to design iterations. Emerging longer-term, real-world data has demonstrated efficacy in a wider spectrum of glaucoma patients with varying subtypes and severities; however, these indications are considered off-label and current evidence remains limited. Data from imaging studies may better inform patient selection and facilitate targeted device implantation. Encouraging results from cost-effectiveness studies, incorporating patient-reported outcomes, may support the wider adoption of iStent technology. Finally, cMIGS involving iStent technology may have potential in leveraging on the favourable safety profile associated with MIGS, while employing multiple mechanisms of action to maximize IOP-lowering efficacy. Overall, iStent technology represents an important component of the current MIGS armamentarium, with its role better clarified as higher-quality and longer-term data becomes available.
Statements
Author contributions
BA: Writing – review & editing, Methodology, Conceptualization, Writing – original draft, Investigation, Supervision, Data curation, Visualization, Resources, Validation, Project administration. NW: Validation, Writing – review & editing, Data curation, Investigation, Writing – original draft, Visualization. BB: Validation, Writing – original draft, Investigation, Writing – review & editing. SL: Investigation, Writing – review & editing, Writing – original draft, Validation.
Funding
The author(s) declared that financial support was not received for this work and/or its publication.
Conflict of interest
BCH Ang is a consultant for, and has received previous research funding and speaker’s honoraria from Glaukos Corporation.
The remaining author(s) declared that this work was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.
Generative AI statement
The author(s) declared that Generative AI was not used in the creation of this manuscript.
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References
1.
Steinmetz JD Bourne RRA Briant PS Flaxman SR Taylor HRB Jonas JB et al . Causes of blindness and vision impairment in 2020 and trends over 30 years, and prevalence of avoidable blindness in relation to VISION 2020: the right to sight: an analysis for the global burden of disease study. Lancet Glob Health. (2021) 9:e144–60. doi: 10.1016/S2214-109X(20)30489-7
2.
Asia-Pacific Glaucoma Society . Asia Pacific glaucoma guidelines. 3rd ed. Amsterdam: Kugler Publications (2016).
3.
Jayaram H . Intraocular pressure reduction in glaucoma: does every mmHg count?Taiwan J Ophthalmol. (2020) 10:255–8. doi: 10.4103/tjo.tjo_63_20,
4.
Saheb H Ahmed IIK . Micro-invasive glaucoma surgery: current perspectives and future directions. Curr Opin Ophthalmol. (2012) 23:96–104. doi: 10.1097/ICU.0b013e32834ff1e7,
5.
Lavia C Dallorto L Maule M Ceccarelli M Fea AM . Minimally-invasive glaucoma surgeries (MIGS) for open angle glaucoma: A systematic review and meta-analysisPLoS One. (2017) 12:e0183142. doi: 10.1371/journal.pone.0183142
6.
Inc P. iStent inject® W Surgery | Glaucoma Products. Glaukos. Available online at: https://www.glaukos.com/glaucoma/products/istent-inject-w/ (Accessed September 18, 2025).
7.
MyAlcon. Hydrus® Microstent MIGS Device | Alcon Professional. Available online at: https://www.myalcon.com/professional/glaucoma/hydrus-microstent/ (Accessed September 18, 2025)
8.
KDB GLIDE® | Excisional Goniotomy for Implant Free Surgery. Available online at: https://www.newworldmedical.com/kdb-glide/ (Accessed September 18, 2025).
9.
Grover DS Godfrey DG Smith O Feuer WJ de Montes Oca I Fellman RL . Gonioscopy-assisted transluminal trabeculotomy, ab interno trabeculotomy: technique report and preliminary results. Ophthalmology. (2014) 121:855–61. doi: 10.1016/j.ophtha.2013.11.001
10.
Nova Eye Medical. iTrackTM. Available online at: https://nova-eye.com/healthcare-professionals/itrack/ (Accessed September 18, 2025).
11.
Wellik SR Dale EA . A review of the iStent® trabecular micro-bypass stent: safety and efficacy. Clin Ophthalmol (Auckl NZ). (2015) 9:677–84. doi: 10.2147/OPTH.S57217
12.
Glaukos. Announces FDA Approval for the iStent inject® Trabecular Micro-Bypass System. Available online at: https://investors.glaukos.com/news/news-details/2018/Glaukos-Announces-FDA-Approval-for-the-iStent-inject-Trabecular-Micro-Bypass-System/default.aspx (Accessed September 18, 2025)
13.
Glaukos . Glaukos Announces More Than 1 Million iStent® Technologies Implanted Worldwide. Available online at: https://investors.glaukos.com/investors/news/news-details/2022/Glaukos-Announces-More-Than-1-Million-iStent-Technologies-Implanted-Worldwide/default.aspx (Accessed July 27, 2025).
14.
Johnson M . What controls aqueous humour outflow resistance?Exp Eye Res. (2006) 82:545–57. doi: 10.1016/j.exer.2005.10.011,
15.
Samuelson TW Katz LJ Wells JM Duh YJ Giamporcaro JE . Randomized evaluation of the trabecular Micro-bypass stent with phacoemulsification in patients with Glaucoma and cataract. Ophthalmology. (2011) 118:459–67. doi: 10.1016/j.ophtha.2010.07.007,
16.
Paletta Guedes RA Gravina DM Paletta Guedes VM Chaoubah A . Standalone implantation of 2–3 trabecular Micro-bypass stents (iStent inject ± iStent) as an alternative to trabeculectomy for moderate-to-severe Glaucoma. Ophthalmol Ther. (2022) 11:271–92. doi: 10.1007/s40123-021-00424-4,
17.
Inc P . iStent inject® | Important Safety Information. Glaukos. Available online at: https://www.glaukos.com/important-safety-information/istent-inject/ (Accessed September 18, 2025)
18.
Vohra V Madgula I Chawla H . Real-world assessment of second-generation trabecular micro-bypass stents in open-angle glaucoma patients. Adv Ophthalmol Pract Res. (2025) 5:16–21. doi: 10.1016/j.aopr.2024.09.002,
19.
Clement C Howes F Ioannidis AS Shiu M Manning D Lusthaus J et al . Two-year multicenter outcomes of iStent inject trabecular Micro-bypass stents combined with phacoemulsification in various types of Glaucoma and ocular hypertension. Clin Ophthalmol. (2020) 14:3507–17. doi: 10.2147/OPTH.S271646,
20.
Fan Gaskin JC Bigirimana D Kong GYX McGuinness MB Atik A Liu L et al . Prospective, randomized controlled trial of cataract surgery vs combined cataract surgery with insertion of iStent inject. Ophthalmol Glaucoma. (2024) 7:326–34. doi: 10.1016/j.ogla.2024.02.004,
21.
Shalaby WS Lam SS Arbabi A Myers JS Moster MR Kolomeyer NN et al . iStent versus iStent inject implantation combined with phacoemulsification in open angle glaucoma. Indian J Ophthalmol. (2021) 69:2488–95. doi: 10.4103/ijo.IJO_308_21,
22.
Guedes RAP Gravina DM Lake JC Guedes VMP Chaoubah A . Intermediate results of iStent or iStent inject implantation combined with cataract surgery in a real-world setting: A longitudinal retrospective study. Ophthalmol Ther. (2019) 8:87–100. doi: 10.1007/s40123-019-0166-x,
23.
Manning D . Real-world case series of iStent or iStent inject trabecular Micro-bypass stents combined with cataract surgery. Ophthalmol Ther. (2019) 8:549–61. doi: 10.1007/s40123-019-00208-x,
24.
Popovic M Campos-Moller X Saheb H Ahmed IIK . Efficacy and adverse event profile of the iStent and iStent inject trabecular micro-bypass for open-angle glaucoma: a meta-analysis. J Curr Glaucoma Pract. (2018) 12:67. doi: 10.5005/jp-journals-10008-1248
25.
Deneri S Merté RL Eter N Brücher V . Comparison of the iStent inject® versus the iStent inject® W—both in combination with cataract surgery—in open-angle glaucoma. J Clin Med. (2023) 12:7259 doi: 10.3390/jcm12237259
26.
Sarkisian SR Grover DS Gallardo MJ Brubaker JW Giamporcaro JE Hornbeak DM et al . Effectiveness and safety of iStent infinite trabecular micro-bypass for uncontrolled glaucoma. J Glaucoma. (2023) 32:9–18. doi: 10.1097/IJG.0000000000002141,
27.
Ahmed IIK Berdahl JP Yadgarov A Reiss GR Sarkisian SR Gagné S et al . Six-month outcomes from a prospective, randomized study of iStent infinite versus Hydrus in open-angle glaucoma: the INTEGRITY study. Ophthalmol Ther. (2025) 14:1005–24. doi: 10.1007/s40123-025-01126-x,
28.
Samuelson TW Sarkisian SR Lubeck DM Stiles MC Duh YJ Romo EA et al . Prospective, randomized, controlled pivotal trial of an ab interno implanted trabecular micro-bypass in primary open-angle glaucoma and cataract. Ophthalmology. (2019) 126:811–21. doi: 10.1016/j.ophtha.2019.03.006,
29.
Melo Araújo KC Velanes Neto EC Bassoli Scoralick AL Kanadani FN Prata TS . Re: Samuelson et al.: prospective, randomized, controlled pivotal trial of an ab interno implanted trabecular micro-bypass in primary open-angle glaucoma and cataract: two-year results. Ophthalmology. (2020) 127:e14–5. doi: 10.1016/j.ophtha.2019.09.042
30.
Leske MC Heijl A Hyman L Bengtsson B . Early manifest Glaucoma trial: design and baseline data. Ophthalmology. (1999) 106:2144–53. doi: 10.1016/S0161-6420(99)90497-9,
31.
Slabaugh MA Bojikian KD Moore DB , Chen PP. The effect of phacoemulsification on intraocular pressure in medically controlled open-angle Glaucoma patients. Am J Ophthalmol2014. 157:26–31, doi: 10.1016/j.ajo.2013.08.023, .
32.
Hengerer FH Auffarth GU Conrad-Hengerer I . iStent inject trabecular Micro-bypass with or without cataract surgery yields sustained 5-year Glaucoma control. Adv Ther. (2022) 39:1417–31. doi: 10.1007/s12325-021-02039-4,
33.
Guedes RAP Gravina DM Guedes VMP Moraes DAG Chaoubah A . Five-year outcomes of iStent inject implantation with or without phacoemulsification in eyes with open-angle Glaucoma. Ophthalmol Ther. (2025) 14:1219–35. doi: 10.1007/s40123-025-01134-x,
34.
Kim M Rho S Lim SH . Five-year outcomes of single trabecular microbypass stent (iStent®) implantation with phacoemulsification in Korean patients. Ophthalmol Ther. (2023) 12, 12:3281–94. doi: 10.1007/s40123-023-00824-8,
35.
Ansari E . 5-year outcomes of single iStent (G1) trabecular microbypass implantation with phacoemulsification in moderately advanced primary open angle glaucoma. Plos One. (2021) 16:e0257015. doi: 10.1371/journal.pone.0257015
36.
Salimi A Watt H Harasymowycz P . Long-term outcomes of two first-generation trabecular micro-bypass stents (iStent) with phacoemulsification in primary open-angle glaucoma: eight-year results. Eye Vis. (2021) 8:43. doi: 10.1186/s40662-021-00263-1
37.
Ahmed IIK Sheybani A De Francesco T Lass JH Benetz BA Samuelson TW et al . Long-term endothelial safety profile with iStent inject in patients with open-angle Glaucoma. Am J Ophthalmol. (2023) 252:17–25. doi: 10.1016/j.ajo.2023.02.014,
38.
Mbagwu M Chapman R Garcia K Masseria C Dickerson JE Cantor LB . Ab interno minimally invasive glaucoma surgery combined with cataract surgery and cataract surgery alone: IRIS® registry study. AJO Int. (2024) 1:100015. doi: 10.1016/j.ajoint.2024.100015
39.
Belovay GW Naqi A Chan BJ Rateb M Ahmed IIK . Using multiple trabecular micro-bypass stents in cataract patients to treat open-angle glaucoma. J Cataract Refract Surg. (2012) 38:1911–7. doi: 10.1016/j.jcrs.2012.07.017
40.
Katz LJ Erb C Carceller Guillamet A Fea AM Voskanyan L Giamporcaro JE et al . Long-term titrated IOP control with one, two, or three trabecular micro-bypass stents in open-angle glaucoma subjects on topical hypotensive medication: 42-month outcomes. Clin Ophthalmol. (2018) 12:255–62. doi: 10.2147/OPTH.S152268,
41.
Fea AM Belda JI Rękas M Jünemann A Chang L Pablo L et al . Prospective unmasked randomized evaluation of the iStent inject (®) versus two ocular hypotensive agents in patients with primary open-angle glaucoma. Clin Ophthalmol [Internet]. (2014) 8:875–82. doi: 10.2147/OPTH.S59932
42.
Spiegel D Wetzel W Neuhann T StĂĽrmer J Höh H GarcĂa-Feijoo J et al . Coexistent primary open-angle Glaucoma and cataract: interim analysis of a trabecular Micro-bypass stent and concurrent cataract surgery. Eur J Ophthalmol. (2009) 19:393–9. doi: 10.1177/112067210901900311
43.
Arriola-Villalobos P MartĂnez-de-la-Casa JM DĂaz-Valle D Fernández-PĂ©rez C GarcĂa-Sánchez J GarcĂa-FeijoĂł J . Combined iStent trabecular micro-bypass stent implantation and phacoemulsification for coexistent open-angle glaucoma and cataract: a long-term study. Br J Ophthalmol. (2012) 96:645–9. doi: 10.1136/bjophthalmol-2011-300218,
44.
Spiegel D GarcĂa-FeijoĂł J GarcĂa-Sánchez J Lamielle H . Coexistent primary open-angle glaucoma and cataract: preliminary analysis of treatment by cataract surgery and the iStent trabecular micro-bypass stent. Adv Ther. (2008) 25:453–64. doi: 10.1007/s12325-008-0062-6,
45.
Spiegel D Wetzel W Haffner DS Hill RA . Initial clinical experience with the trabecular micro-bypass stent in patients with glaucoma. Adv Ther. (2007) 24:161–70. doi: 10.1007/BF02850004
46.
Duch S Buchacra O Milla E Stirbu O . One-year analysis of the iStent trabecular microbypass in secondary glaucoma. Clin Ophthalmol. (2011) 5:321–6. doi: 10.2147/OPTH.S15025
47.
Craven RE Katz JL Wells JM Giamporcaro JE . Cataract surgery with trabecular micro-bypass stent implantation in patients with mild-to-moderate open-angle glaucoma and cataract: two-year follow-up. J Cataract Refract Surg. (2012) 38:1339–45. doi: 10.1016/j.jcrs.2012.03.025,
48.
Fea AM . Phacoemulsification versus phacoemulsification with micro-bypass stent implantation in primary open-angle glaucoma: randomized double-masked clinical trial. J Cataract Refract Surg. (2010) 36:407–12. doi: 10.1016/j.jcrs.2009.10.031,
49.
Fernández-Barrientos Y GarcĂa-FeijoĂł J MartĂnez-de-la-Casa JM Pablo LE Fernández-PĂ©rez C GarcĂa Sánchez J . Fluorophotometric study of the effect of the Glaukos trabecular microbypass stent on aqueous humor dynamics. Invest Ophthalmol Vis Sci. (2010) 51:3327. doi: 10.1167/iovs.09-3972
50.
Craven ER . Trabecular micro-bypass shunt (iStent®micro-bypass stent for open-angle glaucoma: basic science, clinical, and future). Middle East Afr J Ophthalmol. (2015) 22:30. doi: 10.4103/0974-9233.148346,
51.
Le K Saheb H . iStent trabecular micro-bypass stent for open-angle glaucoma. Clin Ophthalmol. (2014) 8:1937–45. doi: 10.2147/OPTH.S45920
52.
Gillmann K Bravetti GE Mermoud A Mansouri K . A prospective analysis of iStent inject microstent positioning: Schlemm Canal dilatation and intraocular pressure correlations. J Glaucoma. (2019) 28:613–21. doi: 10.1097/IJG.0000000000001273,
53.
Ang BCH Chen EJ . Novel surgical technique to manage iStent inject over-implantation. Eur J Ophthalmol. (2023) 33:2309–12. doi: 10.1177/11206721231190417
54.
Khouri AS Megalla MM . Recurrent hyphema following iStent surgery managed by surgical removal. Can J Ophthalmol. (2016) 51:e163–5. doi: 10.1016/j.jcjo.2016.06.017,
55.
Ang BCH Betzler BK Lim SY . Schlemm’s bidirectional fluid wave and luminal blood reflux as novel intraoperative signs confirming optimal placement of the iStent. J Glaucoma. (2025) 34:e28–33. doi: 10.1097/IJG.0000000000002539,
56.
Sarohia GS Rudnisky CJ . Intraoperative predictors of success of iStent placement with cataract surgery. Can J Ophthalmol2025. S0008418225002777. doi: 10.1016/j.jcjo.2025.06.007
57.
Ang BCH Betzler BK Lim SY . Intraoperative optical coherence tomography for ab Interno trabecular bypass Glaucoma surgery. J Glaucoma. (2023) 32:e151–5. doi: 10.1097/IJG.0000000000002232,
58.
Kan JT Betzler BK Lim SY Ang BCH . Anterior segment imaging in minimally invasive glaucoma surgery – a systematic review. Acta Ophthalmol. (2022) 100:e617–e634. doi: 10.1111/aos.14962
59.
Gong Z Johnstone MA Wang RK . iStent insertion orientation and impact on trabecular meshwork motion resolved by optical coherence tomography imaging. J Biomed Opt. (2024) 29:076008. doi: 10.1117/1.JBO.29.7.076008
60.
Bostan C Harasymowycz P . Episcleral venous outflow: a potential outcome marker for iStent surgery. J Glaucoma. (2017) 26:1114–9. doi: 10.1097/IJG.0000000000000799,
61.
Fellman RL Grover DS . Episcleral venous fluid wave in the living human eye adjacent to microinvasive glaucoma surgery (MIGS) supports laboratory research: outflow is limited circumferentially, conserved distally, and favored inferonasally. J Glaucoma. (2019) 28:139–45. doi: 10.1097/IJG.0000000000001126,
62.
Lusthaus JA McCluskey PJ Martin KR . Intraocular pressure spikes following iStent inject and the relationship to aqueous outflow in open angle Glaucoma. J Glaucoma. (2023) 32:600–8. doi: 10.1097/IJG.0000000000002195,
63.
Lusthaus JA Meyer PAR Khatib TZ Martin KR . The effects of trabecular bypass surgery on conventional aqueous outflow, visualized by hemoglobin video imaging. J Glaucoma. (2020) 29:656–65. doi: 10.1097/IJG.0000000000001561,
64.
Ferguson TJ Dockter Z Bleeker A Karpuk KL Schweitzer J Ibach MJ et al . iStent inject trabecular microbypass stent implantation with cataract extraction in open-angle glaucoma: early clinical experience. Eye Vis. (2020) 7:28. doi: 10.1186/s40662-020-00194-3,
65.
Huang AS Saraswathy S Dastiridou A Begian A Mohindroo C Tan JCH et al . Aqueous angiography-mediated guidance of trabecular bypass improves angiographic outflow in human enucleated eyes. Invest Ophthalmol Vis Sci. (2016) 57:4558–65. doi: 10.1167/iovs.16-19644
66.
Healey PR Clement CI Kerr NM Tilden D Aghajanian L . Standalone iStent trabecular Micro-bypass Glaucoma surgery: A systematic review and Meta-analysis. J Glaucoma. (2021) 30:606–20. doi: 10.1097/IJG.0000000000001805,
67.
Oo HH Hong ASY Lim SY Ang BCH . Angle-based minimally invasive glaucoma surgery in normal tension glaucoma: A systematic review and meta-analysis. Clin Experiment Ophthalmol. (2024) 52:740–60. doi: 10.1111/ceo.14408,
68.
Ang BCH Chiew W Yip VCH Chua CH Han WS Tecson IOC et al . Prospective 12-month outcomes of combined iStent inject implantation and phacoemulsification in Asian eyes with normal tension glaucoma. Eye Vis. (2022) 9:27. doi: 10.1186/s40662-022-00294-2
69.
Ang BCH Tecson ICRO Hu JYW Kan JTC Yip LWL . 12-month outcomes of combined phacoemulsification and iStent inject in Asian eyes with Normal tension Glaucoma: A single-Centre experience. Int Ophthalmol. (2022) 42:611–20. doi: 10.1007/s10792-021-02033-3,
70.
Hernstadt DJ Cheng J Htoon HM Sangtam T Thomas A Sng CCA . Case series of combined iStent implantation and phacoemulsification in eyes with primary angle closure disease: one-year outcomes. Adv Ther. (2019) 36:976–86. doi: 10.1007/s12325-019-00899-5,
71.
Salimi A Abu-Nada M Harasymowycz P . Matched cohort study of cataract surgery with and without trabecular microbypass stent implantation in primary angle-closure Glaucoma. Am J Ophthalmol. (2021) 224:310–20. doi: 10.1016/j.ajo.2020.12.032,
72.
Clement C Howes F Ioannidis A Shiu M Manning D Lusthaus JA et al . Multicenter effectiveness and disease stability through 3 years after iStentTrabecular micro-bypass with phacoemulsification in glaucoma and ocular hypertension. Clin Ophthalmol. (2022) 16:2955–68. doi: 10.2147/OPTH.S373290
73.
Zhang N Wang J Chen B Li Y Jiang B . Prevalence of primary angle closure Glaucoma in the last 20 years: A Meta-analysis and systematic review. Front Med. (2020) 7:624179. doi: 10.3389/fmed.2020.624179
74.
Iwase A Suzuki Y Araie M Yamamoto T Abe H Shirato S et al . The prevalence of primary open-angle glaucoma in Japanese. Ophthalmology. (2004) 111:1641–8. doi: 10.1016/j.ophtha.2004.03.029,
75.
Tham YC Li X Wong TY Quigley HA Aung T Cheng CY . Global prevalence of Glaucoma and projections of Glaucoma burden through 2040. Ophthalmology. (2014) 121:2081–90. doi: 10.1016/j.ophtha.2014.05.013,
76.
Tan JCK Clement CI White A Dunn H Soares B Wechsler D et al . Association between prior selective laser trabeculoplasty and phaco- iStent inject efficacy. Clin Experiment Ophthalmol. (2025) doi: 10.1111/ceo.14588
77.
Morita S Sakanishi Y Riyu I Watanabe S Ebihara N . Comparative evaluation of iStent versus iStent inject W combined with phacoemulsification in open angle glaucoma. PLoS One. (2024) 19:e0297514. doi: 10.1371/journal.pone.0297514,
78.
Kim HJ Lim SH . Clinical outcomes of trabecular microbypass stent (iStent) implantation in medically controlled open-angle glaucoma in the Korean population. Medicine. (2020) 99:e21729. doi: 10.1097/MD.0000000000021729,
79.
Jeong JH Lee SJ Ko K Lee JH Lyu J Park MH et al . Plant-derived angiogenin fusion protein’s cytoprotective effect on trabecular meshwork damage induced by benzalkonium chloride in mice. PeerJ. (2020) 8. doi: 10.7717/peerj.9084
80.
Nikhalashree S George R Shantha B Vijaya L Sulochana KN Coral K . Anti-glaucoma medications lowered decorin and altered profibrotic proteins in human tenon’s fibroblasts. Exp Eye Res. (2022) 224:109199 doi: 10.1016/j.exer.2022.109199
81.
Igarashi A Ishida K Shoji N Chu A Falvey H Han R et al . iStent inject® and cataract surgery for mild-to-moderate primary open angle glaucoma in Japan: a cost-utility analysis. Int J Ophthalmol. (2022) 15:954–61. doi: 10.18240/ijo.2022.06.13
82.
Fea AM Cattel F Gandolfi S Buseghin G Furneri G Costagliola C . Cost-utility analysis of trabecular micro-bypass stents (TBS) in patients with mild-to-moderate open-angle glaucoma in Italy. BMC Health Serv Res. (2021) 1:824. doi: 10.1186/s12913-021-06862-x
83.
Guedes RAP Souza CP Dias LLDS Murta L Gravina DM Chaoubah A . A Brazilian cost-utility analysis of trabecular micro-bypass with iStent inject® for the treatment of open-angle glaucoma. Rev Bras Oftalmol. (2022) 81:e0049. doi: 10.37039/1982.8551.20220049
84.
Healey PR Tilden D Jackson D Aghajanian L . A cost-utility analysis of trabecular bypass devices versus usual care for patients with open-angle Glaucoma. PharmacoEconomics Open. (2022) 6:355–65. doi: 10.1007/s41669-021-00312-4,
85.
Patel V Ahmed I Podbielski D Falvey H Murray J Goeree R . Cost-effectiveness analysis of standalone trabecular micro-bypass stents in patients with mild-to-moderate open-angle glaucoma in Canada. J Med Econ. (2019) 22:390–401. doi: 10.1080/13696998.2019.1572013,
86.
Ordóñez JE Ordóñez A Osorio UM . Cost-effectiveness analysis of iStent trabecular micro-bypass stent for patients with open-angle glaucoma in Colombia. Curr Med Res Opin. (2019) 35:329–40. doi: 10.1080/03007995.2018.1506022
87.
Samuelson TW Singh IP Williamson BK Falvey H Lee WC Odom D et al . Quality of life in primary open-angle glaucoma and cataract: an analysis of VFQ-25 and OSDI from the iStent inject® pivotal trial. Am J Ophthalmol. (2021) 229:220–9. doi: 10.1016/j.ajo.2021.03.007
88.
Schweitzer JA Hauser WH Ibach M Baartman B Gollamudi SR Crothers AW et al . Prospective interventional cohort study of ocular surface disease changes in eyes after trabecular Micro-bypass stent(s) implantation (iStent or iStent inject) with phacoemulsification. Ophthalmol Ther. (2020) 9:941–53. doi: 10.1007/s40123-020-00290-6,
89.
Jones L. Maes N. Qidwai U. Ratnarajan G. 2023. 15:Impact of minimally invasive glaucoma surgery on the ocular surface and quality of life in patients with glaucoma. Ther Adv Ophthalmol25158414231152765. doi: 10.1177/25158414231152765
90.
Al Habash A Nagshbandi AA . Quality of life after combined cataract and minimally invasive glaucoma surgery in glaucoma patients. Clin Ophthalmol Auckl NZ. (2020) 14:3049–56. doi: 10.2147/OPTH.S276124
91.
Otarola F Virgili G Shah A Hu K Bunce C Gazzard G . Ab interno trabecular bypass surgery with Schlemm’s canal microstent (Hydrus) for open angle glaucoma. Cochrane Database Syst Rev. (2020) 3:CD012740. doi: 10.1002/14651858.CD012740.pub2
92.
Bicket AK Le JT Azuara-Blanco A Gazzard G Wormald R Bunce C et al . Minimally invasive glaucoma surgical techniques for open-angle glaucoma: an overview of Cochrane systematic reviews and network meta-analysis. JAMA Ophthalmol. (2021) 139:983. doi: 10.1001/jamaophthalmol.2021.2351,
93.
Hu R Guo D Hong N Xuan X Wang X . Comparison of Hydrus and iStent microinvasive glaucoma surgery implants in combination with phacoemulsification for treatment of open-angle glaucoma: systematic review and network meta-analysis. BMJ Open. (2022) 12:e051496. doi: 10.1136/bmjopen-2021-051496,
94.
Guedes J Amaral DC de Oliveira Caneca K Cassins Aguiar EH de Oliveira LN Mora-Paez DJ et al . Kahook dual blade goniotomy versus iStent implantation combined with phacoemulsification: a systematic review and meta-analysis. J Glaucoma. (2025) 34:232–47. doi: 10.1097/IJG.0000000000002522
95.
Fernandez-Alcalde C Jones L Pantalon AD Ratnarajan G . Three-years follow-up of combined phacoemulsification, iStent and endocyclophotocoagulation. Eur J Ophthalmol. (2025) 35:2083–90. doi: 10.1177/11206721251338996,
96.
Pantalon AD Barata ADDO Georgopoulos M Ratnarajan G . Outcomes of phacoemulsification combined with two iStent inject trabecular microbypass stents with or without endocyclophotocoagulation. Br J Ophthalmol. (2020) 104:1378–83. doi: 10.1136/bjophthalmol-2019-315434,
97.
Qidwai U Jones L Ratnarajan G . A comparison of iStent combined with phacoemulsification and endocyclophotocoagulation (ICE2) with the PreserFlo MicroShunt and XEN-45 implants. Ther Adv Ophthalmol. (2022) 14:25158414221125697. doi: 10.1177/25158414221125697,
98.
El Helwe H Oberfeld B Golsoorat Pahlaviani F Falah H Trzcinski J Solá-Del VD . Comparing outcomes of phacoemulsification and Endocyclophotocoagulation with either dual blade Goniotomy (PEcK) or two trabecular stents (ICE2). Clin Ophthalmol. (2023) 17:2879–88. doi: 10.2147/OPTH.S431356,
99.
Heersink M Dovich JA . Ab interno canaloplasty combined with trabecular bypass stenting in eyes with primary open-angle glaucoma. Clin Ophthalmol. (2019) 13:1533–42. doi: 10.2147/OPTH.S215667,
Summary
Keywords
glaucoma - surgery, iStent, iStent inject, iStent inject W, minimally invasive glaucoma surgery, primary open angle glaucoma
Citation
Ang BCH, Wong NSQ, Betzler B and Lim SY (2026) From first generation to the next: evolution and research trends in iStent technology. Front. Med. 12:1724886. doi: 10.3389/fmed.2025.1724886
Received
14 October 2025
Revised
12 December 2025
Accepted
31 December 2025
Published
23 January 2026
Volume
12 - 2025
Edited by
Karanjit Kooner, University of Texas Southwestern Medical Center, United States
Reviewed by
Parul Ichhpujani, Government Medical College and Hospital, India
Updates
Copyright
© 2026 Ang, Wong, Betzler and Lim.
This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) and the copyright owner(s) are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.
*Correspondence: Bryan Chin Hou Ang, drbryanang@gmail.com
†These authors have contributed equally to this work and share first authorship
Disclaimer
All claims expressed in this article are solely those of the authors and do not necessarily represent those of their affiliated organizations, or those of the publisher, the editors and the reviewers. Any product that may be evaluated in this article or claim that may be made by its manufacturer is not guaranteed or endorsed by the publisher.