Assessment of Anterior Chamber Angle Parameters Using Anterior Segment OCT in Nigerians with Suspected Angle Closure at the National Eye Centre, Kaduna

Angle-closure glaucoma accounts for a substantial proportion of glaucoma-related blindness globally, yet its anatomical underpinnings in African populations are undercharacterized due to limited access to advanced anterior segment imaging. This study uses anterior segment optical coherence tomography (AS-OCT) to assess anterior chamber angle parameters in patients with suspected angle closure attending the National Eye Centre, Kaduna, North West Nigeria. A cross-sectional analytical design will be employed, recruiting 160 patients with clinical suspicion of narrow angles. AS-OCT will measure trabecular-iris space area (TISA), angle opening distance (AOD), angle recess area (ARA), iris curvature, and lens vault in both light and dark conditions. Comparisons will be made against a control group of 80 age-matched open-angle individuals. Independent predictors of angle closure will be identified using logistic regression. The study expects to find significantly smaller TISA and AOD values in patients with suspected angle closure, with iris plateau configuration as a significant predictor. Findings will contribute to the imaging evidence base for angle-closure glaucoma risk stratification in the Nigerian population and will support clinical decision-making for laser peripheral iridotomy at the National Eye Centre. This research provides locally grounded AS-OCT normative data for angle assessment and advances the management of angle-closure disease in the North West zone. Keywords: anterior segment OCT, angle closure, glaucoma, National Eye Centre, anterior chamber