Longitudinal Evaluation of Microvascular Changes and Imaging Biomarkers Associated with Visual Prognosis in Retinal Artery Occlusion.

Abstract

To longitudinally assess changes in macular thickness and microvascular metrics in retinal artery occlusion (RAO) patients, and to identify imaging biomarkers associated with visual prognosis. Retrospective cohort study. 56 RAO patients (57 eyes) and 27 controls (30 eyes). Comprehensive ophthalmic evaluations were performed, including macular OCT and 6 × 6 mm swept-source OCT angiography (SS-OCTA). Retinal thickness, macular ischemic area, ischemia-fovea distance, vessel skeletonized density (VSD), vessel density (VD), and foveal avascular zone (FAZ) area were quantified. Receiver operating characteristic (ROC) and linear regression analyses assessed imaging biomarkers correlated with visual outcomes. Longitudinal changes in retinal structure and microvasculature, and their associations with final visual acuity (VA). Among 57 RAO eyes (28 BRAO) with a median follow-up of 83.0 (35.5, 172.0) weeks, retinal thickness significantly decreased over time (P < .05), while macular ischemic area expanded from 64.97% to 73.58% (P = .002). In a subset of 24 RAO eyes with longitudinal SS-OCTA scans, eyes with a baseline ischemic area ≤ 1/3 of the scan area showed increased VSD and VD in both plexuses over time (P < .05). FAZ area was significantly larger in CRAO compared to BRAO (P = .0001), although no statistically significant change in FAZ area was observed over time (P = .341), a numerical increase was noted in CRAO cases. Better baseline VA, greater ischemic distance to fovea, smaller initial ischemic area, higher VSD and VD in SCP, and smaller FAZ area were associated with better final VA (all P < .05, AUC: 0.80-0.89). Multivariable linear regression identified baseline ischemic area and FAZ area as independent predictors of final VA (P = .003, 0.008). Multimodal quantification demonstrates the progressive ischemia in RAO and potential reperfusion in eyes with limited involvement. Ischemic area and FAZ area are key imaging biomarkers for visual prognosis.