Ang, Bryan C H

ABSTRACT Background The adoption of angle‐based minimally invasive glaucoma surgery (MIGS) procedures has accelerated in recent years; however, inherent limitations remain. Imaging‐based techniques across the pre‐, intra‐ and post‐operative stages of surgery may facilitate patient selection and improve surgical outcomes. This systematic review explores the application of imaging‐based techniques to visualise aqueous humour outflow (AHO) in angle‐based MIGS. Methods A literature search was performed on PubMed, EMBASE and Cochrane Library from inception to 16 February 2025. Cohort, cross‐sectional and observational studies reporting the use of imaging‐based techniques to visualise AHO in angle‐based MIGS were included in this review. Results An initial 393 studies were identified, with 21 studies included in final analysis. Imaging techniques reported in literature included various methods to directly observe episcleral veins, haemoglobin venous imaging (HVI), fluorescein and indocyanine green (ICG) aqueous angiography, channelogram and anterior segment optical coherence tomography angiography (AS‐OCTA). Visualisation of AHO pre‐ and intra‐operatively may predict surgical outcomes, aiding in patient selection and surgical prognostication. Intra‐operative imaging may facilitate targeted placement of MIGS in areas of initially angiographically low or high areas of AHO. AHO assessment pre‐, intra‐ and post‐operatively may allow comparative analysis of surgical success and efficacy across various angle‐based MIGS. Conclusions Imaging‐based techniques visualising AHO have significant potential to improve surgical outcomes of angle‐based MIGS.

Objective Glaucoma and cancer are debilitating diseases with increasing global prevalence and morbidity. However, current literature lacks a systematic consolidation of their relationships and interactions. This systematic review aims to (A) summarize the association between intraocular/non-ocular cancers and their treatments with the prevalence and etiology of glaucoma, (B) explore glaucoma as a risk factor for complications or poor prognosis for intraocular cancer, and (C) explore the management of glaucoma secondary to cancer therapies. Methods A systematic search was performed from inception to July 2025 across three databases with variants of ‘cancer’ and ‘glaucoma’ as search terms. Findings were narratively synthesized. Results Of 8,103 identified studies, 44 were included in this review. Eighteen studies reported increased glaucoma prevalence amongst intraocular and non-ocular cancer patients. Fifteen studies suggested increased risk of regional invasion, metastases, and high-risk histopathologies when intraocular cancers co-occurred with glaucoma. Corticosteroids in cancer therapy have been linked to intraocular pressure (IOP) elevation, while androgen deprivation therapy was associated with lowered glaucoma risk. Conclusion Given the relationship between glaucoma and intraocular/non-ocular cancers, strategies to monitor and manage glaucoma risk following cancer diagnosis and/or therapy may be considered. Glaucoma may be an early sign of complications in intraocular cancers.

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: Glaucoma patients with significant visual field defects show poorer driving performance, higher collision risks, and a greater likelihood of driving cessation. They face difficulties with lane maintenance, slower hazard responses, and self-regulation while driving. Purpose: Glaucoma is a chronic, progressive optic neuropathy associated with visual field (VF) defects, which in advanced disease has been shown to affect patients’ activities of daily living. This systematic review qualitatively analyzes existing literature that explores the impact of glaucomatous VF loss on the driving performance of glaucoma patients, the extent of driving limitation and cessation, as well as the risk of motor vehicle collisions (MVCs). Methods: A literature search of MEDLINE and Embase (via Ovid), PubMed, Cochrane Library, and Web of Science databases was performed for studies published from 2003 to 2023, with the terms “glaucoma,” “visual field defect/disorder,” and “driving,” followed by selective vetting based on inclusion criteria. Within studies, data pertaining to study design, subject demographics, VF defect characteristics, driving performance and related outcomes were extracted. Results: Initial search yielded 835 studies, with 20 studies selected. Three more studies were included through hand-searching, with a total of 23 studies included for final review. Moderate to severe VF defects resulted in poorer driving performance, with slower response times to road hazards, decreased ability for lane maintenance, and increased difficulty driving at night. Patients with more severe VF defects and with bilateral glaucoma were more likely to limit or cease driving compared with those with milder and unilateral glaucoma. A greater severity of VF loss was associated with a higher risk of MVCs. Conclusion: More severe glaucomatous VF and bilateral glaucoma is associated with worse driving performances and a higher risk of MVCs, in both simulator and real-world settings.

A systematic review was conducted of studies published up to 30 August 2024. Studies comparing conventional visual field (VF) indices, ability to detect central visual field defects (CVFDs), structure–function (S-F) concordance, and test characteristics across the HVF 24-2C SITA-Faster, 24-2 SITA-Standard/Faster, and 10-2 SITA-Standard/Fast tests were included. Eight studies with 1239 subjects (49.1% male; mean age, 54.8–66.9 years) were analyzed. The 24-2C produced similar global VF indices compared to the 10-2 and 24-2 (Standard/Faster) (ICC = 0.95 and 0.80, p < 0.001), detected more VF defects and CVFD clusters, and demonstrated greater S-F concordance than the 24-2 (Standard/Faster). Although the 10-2 (Standard/Fast) detected significantly more CVFDs and had a greater S-F concordance, the agreement between the 24-2C and 10-2 grids was substantial (ĸ = 0.488 to 0.708). The 24-2C was also faster compared to the 24-2 Standard and 10-2 (Standard/Fast), with comparable false positives, higher false negatives, and fewer fixation losses than the 24-2 Standard. In conclusion, the HVF 24-2C is quicker and identifies more CVFDs than the 24-2 grid, demonstrates high agreement with the 10-2 grid, and aids in CVFD screening.

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.

Objective To evaluate the safety and efficacy of MicroPulse Transscleral Laser Therapy (MicroPulse TLT) with the Revised P3 ® Delivery Device. Design Prospective, single-surgeon, interventional study in a tertiary hospital setting. Participants Sixty-two eyes of 40 patients with refractory glaucoma. Methods All subjects received 360-degree MicroPulse TLT treatment (2500 mW, 31.33% duty cycle) over a total of 240 s (8 sweeps; n = 20), 300 s (10 sweeps; n = 22), or 200 s (10 sweeps; n = 20). Participants were followed up for 6 months to assess changes in intraocular pressure (IOP), glaucoma medication burden, and best-corrected visual acuity (BCVA). Surgical success was defined as a reduction of IOP ≥ 30% from baseline and between 6–18 mmHg at last follow-up with no additional anti-glaucoma medications or secondary reinterventions. Results Surgical success was achieved in 72.7% (300 s group), 75.0% (240 s group), and 80.0% (200 s group) of eyes. Mean IOP was significantly reduced ( p < 0.001) by 49.0% (300 s group), 45.66% (240 s group), and 39.8% (200 s group) at 6 months. With all groups combined, the mean number of glaucoma medications was significantly reduced by 17.8% ( p = 0.005), and no significant changes in BCVA were observed at 6 months. Complications were minimal, including four eyes with IOP spikes, one eye with hyphema, and one eye with cystoid macular edema (CME), all of which resolved. Two eyes of the total sample (3.2%) required secondary glaucoma surgery before 6 months. Conclusions Second-generation MicroPulse TLT at fluence values of 154–229 J/cm 2 appears to be a safe and effective option for IOP reduction in refractory glaucoma.