Ophthalmic Artery Morphology and Hemodynamics in Ocular Ischemic Syndrome: A Computational Fluid Dynamics and Particle Image Velocimetry Study

PURPOSE. The purpose of this study was to investigate the morphological and hemodynamic characteristics of the ophthalmic artery (OA) in ocular ischemic syndrome (OIS) and identify features potentially associated with disease pathogenesis. METHODS. This retrospective case-control study included 33 patients with OIS, 22 patients with internal carotid artery stenosis (ICAS), and 29 healthy controls. Clinical data and ophthalmic examinations were collected. The morphology and hemodynamics of the OA were quantified using three-dimensional (3D) reconstruction and computational fluid dynamics (CFD). Particle image velocimetry provided a qualitative consistency check for the CFD results. RESULTS. The OA diameter in the OIS group was significantly smaller than that in the control and ICAS groups. Compared with the control group, the OIS group showed lower blood flow velocity and wall shear stress (8.25 ± 5.34 Pa vs. 13.50 ± 6.24 Pa; P = 0.004) at the OA origin. A smaller OA diameter and lower wall shear stress at the OA origin were significantly associated with the presence of OIS. A low wall shear stress was observed at the OA origin regardless of the flow direction in the OIS. Patients with high-velocity retrograde OA flow present severe ocular ischemic manifestations. CONCLUSIONS. Low wall shear stress may be a consistent hemodynamic characteristic of eyes with OIS. This hemodynamic feature may induce inward remodeling of the OA, leading to further luminal narrowing and exacerbation of ocular ischemia. The presence of high-velocity retrograde OA flow may indicate a severe degree of ocular ischemia, highlighting the potential of OA hemodynamics for improving risk stratification and guiding management.