Dada, Tanuj

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.

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.