Lim, Sheng Yang

ABSTRACT Background Ab‐interno canaloplasty (ABiC) may be performed as a standalone procedure or in combination with phacoemulsification (ABiC+Phaco). This study aims to examine the comparative surgical outcomes of both procedures. Methods PubMed, EMBASE and CENTRAL were searched for randomised controlled trials, cohort studies and retrospective case series published from inception to 31 March 2025 that compared outcomes of standalone ABiC and ABiC+Phaco in the treatment of open‐angle glaucoma (OAG). Random‐effects meta‐analysis was performed to pool the mean difference in intraocular pressure (IOP) and glaucoma medications compared to baseline. Results Eight studies with a pooled total of 663 eyes were included in final analysis. There was no significant difference in IOP‐lowering efficacy between ABiC+Phaco and standalone ABiC across all timepoints (6 months, 1 year, 2 years and 3 years) with a mean difference of 0.25 mmHg (95% CI: −0.98 to 1.48) at 3 years. There was also no significant difference in glaucoma medication reduction between ABiC+Phaco and standalone ABiC across all timepoints, with a mean difference of 0.03 medication reduction (95% CI: −0.18 to 0.23) at 3 years. A small IOP‐lowering benefit of ABiC+Phaco versus standalone ABiC in primary OAG‐only studies (mean difference 0.75 mmHg, 95% CI: 0.03–1.47) was observed at 3 years. Conclusion Our meta‐analysis suggests that phacoemulsification may not offer significant additional IOP and glaucoma medication reduction to standalone ABiC. However, results should be interpreted with caution due to a moderate risk of bias across all included studies. Regardless, our findings are consistent with existing literature on the effect of adjunctive phacoemulsification on other ab‐interno MIGS.

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.

Purpose: Trabecular micro-bypass devices (TBDs) such as the iStent series (Glaukos Corporation), are effective in reducing intraocular pressure (IOP). However, precise placement of TBDs is crucial in achieving surgical efficacy, as device malpositioning may lead to suboptimal IOP reduction. We demonstrate 2 novel intraoperative signs to aid confirmation of accurate iStent placement, without reliance on imaging technologies. Methods: Surgical technique report with video accompaniment. Surgical Technique: Two intraoperative clinical signs that confirm optimal iStent placement are described: (1) Luminal Blood Reflux—achieved by gently decompressing the anterior chamber, with or without flushing of the stent lumen with balanced salt solution (BSS), thereby confirming stent positioning in the Schlemm canal (SC). (2) Schlemm’s Bidirectional Fluid Wave (SBFW)—observable when flushing with BSS, suggesting fluid movement in the canal segments adjacent to the iStent device, thereby confirming stent patency and positioning in the SC. Conclusion: The identified signs are useful, feasible, and reproducible indicators of accurate iStent placement. Future studies may evaluate the application of these confirmatory maneuvers in diverse clinical contexts and further establish a correlation with clinical outcomes.

AbstractBackgroundThis systematic review and meta‐analysis quantitatively examines the efficacy of angle‐based minimally invasive glaucoma surgery (MIGS) in normal tension glaucoma (NTG).MethodsA literature search was performed on Medline, Embase, PubMed, CINAHL and Cochrane Library from inception until 20 December 2022. Pilot, cohort, observational studies and randomised controlled trials including at least 5 subjects undergoing angle‐based MIGS (trabecular‐bypass devices, excisional trabeculotomy, goniotomy and ab‐interno canaloplasty) for NTG, with or without cataract surgery, were included. Meta‐analysis of continuous outcome using the meta routine in R version 2022.12.0+353 was performed to determine mean intraocular pressure (IOP) and anti‐glaucoma medication (AGM) reduction post‐operatively.ResultsOf the 846 studies initially identified, 15 studies with a pooled total of 367 eyes which underwent combined phacoemulsification and angle‐based MIGS were included for final meta‐analysis. Outcomes of the iStent were reported in 5 studies, iStent inject in 7 studies, Hydrus Microstent in 1 study, Kahook Dual Blade in 3 studies, and Trabectome in 2 studies. There was significant reduction in both IOP and AGM post‐operatively at 6 months (2.44 mmHg, 95%CI: 1.83–3.06; 1.21 AGM, 95%CI: 0.99–1.44), 12 months (2.28 mmHg, 95%CI: 1.71–2.84; 1.18 AGM, 95%CI: 0.90–1.47), 24 months (2.10 mmHg, 95%CI: 1.51–2.68; 1.26 AGM, 95%CI: 0.85–1.68) and 36 months (2.43 mmHg, 95%CI: 1.71–3.15, 0.87 AGM, 95%CI: 0.21–1.53) (all p < 0.05). Subgroup analysis on combined phacoemulsification‐iStent inject surgery demonstrated a reduction in both IOP (2.31 mmHg, 95%CI: 1.07–3.56, p < 0.001) and AGM (1.07 AGM, 95%CI: 0.86–1.29, p < 0.001) at 12 months post‐operatively.ConclusionsAngle‐based MIGS combined with phacoemulsification effectively reduces IOP and AGM in NTG eyes for up to 36 months after surgery.

Surgery has long been an important treatment for limiting optic nerve damage and minimising visual loss in patients with glaucoma. Numerous improvements, modifications, and innovations in glaucoma surgery over recent decades have improved surgical safety, and have led to earlier and more frequent surgical intervention in glaucoma patients at risk of vision loss. This review summarises the latest advancements in trabeculectomy surgery, glaucoma drainage device (GDD) implantation, and minimally invasive glaucoma surgery (MIGS). A comprehensive search of MEDLINE, EMBASE, and CENTRAL databases, alongside subsequent hand searches—limited to the past 10 years for trabeculectomy and GDDs, and the past 5 years for MIGS—yielded 2283 results, 58 of which were included in the final review (8 trabeculectomy, 27 GDD, and 23 MIGS). Advancements in trabeculectomy are described in terms of adjunctive incisions, Tenon’s layer management, and novel suturing techniques. Advancements in GDD implantation pertain to modifications of surgical techniques and devices, novel methods to deal with postoperative complications and surgical failure, and the invention of new GDDs. Finally, the popularity of MIGS has recently promoted modifications to current surgical techniques and the development of novel MIGS devices.