Betzler, Bjorn Kaijun

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.

Precis: This retrospective multicentre study of 77 NTG eyes undergoing phacoemulsification and Hydrus implantation showed a sustained reduction in medication burden, while maintaining IOP levels. Complications were rare and nonsight-threatening. Purpose: To evaluate 36-month outcomes of combined phacoemulsification and Hydrus Microstent implantation (Phaco-Hydrus) in eyes with normal tension glaucoma (NTG). Methods: This multicentre retrospective study included 77 NTG eyes from Singapore and Canada that underwent Phaco-Hydrus between 2014 and 2023. Primary outcomes were changes in intraocular pressure (IOP) and medication burden, and cumulative success probabilities from Kaplan-Meier (KM) analyses. Longitudinal changes were analysed using generalized estimating equations. Results: Of 77 eyes, 31 completed 36 months of follow-up. Mean baseline IOP and medications was 13.5±2.5 mm Hg and 1.7±0.9, respectively. No significant reductions in IOP were observed. A sustained reduction in medication use was observed at all follow-up timepoints ( P ≤0.001). At 36 months, medication use decreased by −0.7±0.2 [adjusted mean difference±SE of the mean [SEM]]. Proportion of medication-free eyes increased from 7.8% (n=6/77) at baseline to 45.2% (n=14/31) at 36 months. Cumulative success probabilities varied widely based on definitions. When defined as a decrease in ≥1 medication from baseline without an increase in IOP, or IOP ≤15 mm Hg and reduced ≥20% from baseline while medication-free, and no additional laser or incisional glaucoma surgery, this was 40.7% at 36 months. No visual field mean deviation progression was detected. Adverse events were infrequent and nonsight-threatening. Conclusion: In eyes with NTG, Phaco-Hydrus may offer a greater role in medication reduction or achieving a medication-free status over 36 months, rather than absolute IOP reduction.

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.

Précis: ASOCT features of greater bleb height, thicker bleb walls, and lower reflectivity are associated with trabeculectomy success, supporting the ASOCT’s utility in monitoring and predicting outcomes postsurgery through standardized imaging protocols. Purpose: To evaluate and quantify the relationship between bleb characteristics on ASOCT with surgical outcomes. Methods: A literature search was conducted across Medline, Embase, Cochrane, and Scopus for studies from the past 20 years, until 16 September 2024, on “glaucoma,” “trabeculectomy,” and “ASOCT.” Data collected included patient characteristics, each study’s definition of bleb success, clinical outcomes, as well as bleb characteristics. A literature review was conducted on studies that could not be used for meta-analysis. Results: Eleven studies, with a pooled total of 528 eyes in 517 patients, were included in the final meta-analysis. Successful blebs had significantly higher mean bleb height [mean difference (MD) 0.38 mm, 95% CI: 0.20-0.56 mm, P=0.002], greater maximum bleb wall thickness (MD: 0.21 mm, 95% CI: 0.07-0.35 mm, P=0.009), and decreased reflectivity (MD: −48.9%, 95% CI: −78.3 to −19.4%, P=0.010), compared with failed blebs. No significant differences were found in bleb fluid cavity height and bleb area. Narrative synthesis revealed that wider blebs, increased fluid-filled cavity height, increased number of microcysts, larger filtration opening widths, and multiform bleb walls were also associated with higher rates of bleb success. Early bleb parameters were statistically significant predictors of bleb success up to 12 months postoperatively. Conclusions: Greater bleb height, thicker bleb walls, and lower reflectivity on ASOCT are consistently associated with successful trabeculectomy outcomes. The ASOCT may be useful in predicting bleb success and in supplementing postoperative monitoring, hence guiding timely medical or procedural interventions, to ensure long-term bleb success.

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.

Précis: This study reports 12-month outcomes of combined phacoemulsification and Hydrus Microstent implantation in Asian eyes with moderate-to-severe normal tension glaucoma (NTG), demonstrating a significant reduction in glaucoma medications with an excellent intra and postoperative safety profile. Objective: To evaluate the 12-month safety and efficacy outcomes of combined phacoemulsification and Hydrus Microstent (Ivantis Inc.) implantation in Asian eyes with moderate to severe NTG. Methods: Retrospective study of consecutive surgeries performed from August 2019 to August 2021 in a single tertiary eye centre in Singapore. Outcome measures included a reduction in intraocular pressure (IOP), number of glaucoma medications, and intra and postoperative complications. Results: Data from 21 eyes of 21 subjects were analyzed. All subjects were ethnic Chinese, and the majority were males (14, 66.7%). At baseline, the mean IOP was 13.3 (2.3) mm Hg, all eyes had a Humphrey visual field mean deviation of ≥−6 dB [mean: −13.9 (4.3) dB], and all eyes were on at least one glaucoma medication. There was no statistically significant reduction in IOP at all time points compared with baseline (all P > 0.05). However, the median number of medications was reduced from 2 to 0 at all time points, up to postoperative month (POM) 12 (all P < 0.001). There were no intraoperative complications. No eyes underwent secondary glaucoma procedures nor lost any Snellen line of visual acuity by POM12. One (4.8%) eye experienced numerical hypotony at postoperative day 1, which resolved conservatively. Two (9.5%) eyes underwent laser iridoplasty for stent occlusion by iris. There was no deterioration in Humphrey visual field mean deviation at POM12 compared with baseline (n = 20, P > 0.05). Conclusion: Combined phacoemulsification and Hydrus Microstent implantation were effective in reducing medication burden in Asian eyes with moderate to severe NTG, up to 12 months postoperatively.

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.