Aqueous Humour Outflow Assessment Using Imaging-Based Techniques in Angle-Based Minimally Invasive Glaucoma Surgery...

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.

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.

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.

Imaging-based techniques visualising AHO have significant potential to improve surgical outcomes of angle-based MIGS.