Ang, Bryan C H

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.

Purpose of review The introduction of minimally invasive glaucoma surgery (MIGS) has changed the surgical landscape of glaucoma surgery. For more than four decades, the most commonly performed glaucoma surgery around the world has been the trabeculectomy. This article examines whether trabeculectomy is still the predominant procedure in glaucoma today, in the context of rapidly emerging MIGS devices and procedures. Recent findings There is a growing trend of mild to moderate glaucoma cases undergoing MIGS procedures instead of trabeculectomy. Glaucoma drainage device implantation may also have taken away a significant share of the filtering surgery performed for more severe glaucoma. In addition, the availability and economics of implants has an influence on the prevalence of trabeculectomy. Summary Currently, trabeculectomy surgery is still the most common glaucoma surgery performed around the world. However, the proportion of glaucoma surgeries undergoing MIGS is increasing rapidly.

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.

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.

Abstract Purpose To assess intra‐ (repeatability) and inter‐observer (reproducibility) variability of laser speckle flowgraphy (LSFG) for retinal blood flow (RBF) measurement in 20 eyes of wild type (C57BL/6J) mice and effect of intravitreal Aflibercept on RBF in optic nerve head (ONH) region of 10 eyes of Ins2 (Akita) diabetic mice. Methods ‘Mean blur rate (MBR)’ was measured for all quadrants of tissue area (MT), vessel (MV) and total area (MA) of ONH region. Changes in MT were analysed at each timepoint. Repeatability was evaluated by measuring MBR variability without changing mouse head position, and reproducibility after resetting mouse head position by another operator. Coefficient of repeatability (CR) through Bland–Altman plot method coefficient of variation (COV) and Intraclass correlation coefficient (ICC) was calculated. Intravitreal Aflibercept (1 μg) was administered to Akita eyes and intraocular pressure (IOP) was measured using a tonometer at baseline, day 7, 14, 21 and 28 post‐injection. Hurvich and Tsai's criterion was used. Results Coefficient of repeatability values of repeatability and reproducibility for all quadrants were within limits of agreement. Reliability was excellent (ICC 0.98–0.99) and reproducibility was moderate to excellent (ICC 0.64–0.96). There was a non‐significant IOP increase in all Akita eyes at Day 28 ( p > 0.05), and significant increase in MT in all quadrants at Day 21 and superior, inferior and temporal quadrants at Day 28 ( p < 0.05). Conclusion Laser speckle flowgraphy demonstrates excellent repeatability and moderate to excellent reproducibility in measuring RBF. Intravitreal Aflibercept injection results in a significant increase in MT up to 28 days post‐injection without significant increase in IOP.

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.

The incidence of both cataract and glaucoma is increasing globally. With increasing patient expectation and improved technology, premium intraocular lenses (IOLs), including presbyopia-correcting and toric IOLs, are being increasingly implanted today. However, concerns remain regarding the use of premium IOLs, particularly presbyopia-correcting IOLs, in eyes with glaucoma. This systematic review evaluates the use of premium IOLs in glaucoma. A comprehensive search of the MEDLINE database was performed from inception until 1 June 2023. Initial search yielded 1404 records, of which 12 were included in the final review of post-operative outcomes. Studies demonstrated high spectacle independence for distance and good patient satisfaction in glaucomatous eyes, with positive outcomes also in post-operative visual acuity, residual astigmatism, and contrast sensitivity. Considerations in patient selection include anatomical and functional factors, such as the type and severity of glaucomatous visual field defects, glaucoma subtype, presence of ocular surface disease, ocular changes after glaucoma surgery, and the reliability of disease monitoring, all of which may be affected by, or influence, the outcomes of premium IOL implantation in glaucoma patients. Regular reviews on this topic are needed in order to keep up with the rapid advancements in IOL technology and glaucoma surgical treatments.