Anterior segment optical coherence tomography (AS-OCT) identification of anterior chamber hyper-reflective particles: a meta-analytic approach to methods and metrics

Eye (Lond). 2026 May 9. doi: 10.1038/s41433-026-04504-2. Online ahead of print.

ABSTRACT

Ocular inflammation, if undetected or untreated, can lead to sight loss. Inflammation occurs in uveitis, following ocular trauma or intraocular surgery. Detection currently relies on slit-lamp grading using the International Standardized Uveitis Nomenclature (ISUN). However, this is subjective and prone to variability, which limits monitoring. Anterior segment optical coherence tomography (AS-OCT) offers an objective alternative by assessing hyper-reflective particles within the anterior chamber as digital indicators of inflammation. This systematic review with a meta-analytic approach assessed how AS-OCT detects, defines and quantifies these particles across published studies. A PROSPERO-registered protocol guided a comprehensive literature search. Of 466 identified studies, 21 met eligibility criteria. Uveitis appeared in 57% of studies, whilst 29% incorporated healthy controls. Substantial methodological variation was identified, including scan acquisition and particle-counting techniques. Hyper-reflective particles were quantified using manual, automated, or combined approaches. Automated methods employed coding, algorithms, or image-processing software. Particle size definitions ranged from qualitative descriptions, up to 50 pixels, while 38% of studies provided no definition. Although a correlation between SUN and AS-OCT occurred, there was significant overlap between hyper-reflective particles detected by AS-OCT and SUN grades. Significant heterogeneity in imaging protocols, particle definitions and quantification methods limited meta-analysis. To address and strengthen clinical applicability, we propose preliminary minimum technical reporting standards, including recommended scan acquisition, region-of-interest, particle definition and analytic workflows to ensure standardisation. Establishing normative adult datasets would further support interpretation, particularly given unexpected paediatric findings. Future studies are required to address these findings, for which we propose a research agenda.

PMID:42106504 | DOI:10.1038/s41433-026-04504-2