Alterations in Retinal Vasculometry After Acute Primary Angle Closure Episode: A Comparative Analysis

Purpose: To evaluate retinal vasculometry alterations in successfully treated acute primary angle closure (APAC) eyes versus unaffected fellow eyes. Methods: In this cross-sectional study of 116 patients with unilateral APAC, retinal photographs obtained within two weeks after intraocular pressure (IOP) control were analyzed using deep learning-based software to evaluate retinal vascular parameters. The main outcome included caliber, density, complexity, tortuosity, and branching angle parameters. Results: Compared to fellow eyes, APAC eyes showed larger retinal vein caliber (P < 0.001), increased length-to-diameter ratio in arteries and veins (P < 0.001 and = 0.001), and lower arteriovenous ratio from quantile 4 (AVRQ4) (P < 0.001). Additionally, APAC eyes demonstrated reduced bifurcation densities, fractal dimension (FD), and branching angle for arteries and veins (all P ≤ 0.005). Multivariate analysis identified three independent factors associated with APAC: higher IOP (odd ratio [OR] = 1.073, P = 0.003), lower AVRQ4 (OR = 0.957, P = 0.025), and decreased arterial FD (OR = 0.953, P = 0.028). Conclusions: APAC eyes exhibit significant retinal vasculometry alterations despite IOP control. Longitudinal studies are needed to determine whether these alterations contribute to the development of glaucomatous optic neuropathy. Translational Relevance: The observed changes in artery-to-vein caliber ratio and arterial complexity may help clinicians identify eyes at risk for progressive damage despite normalized IOP. These findings support the development of supplementary monitoring strategies using standard fundus photography in post-APAC management.