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

Figures

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  Figure 1.. Morphological and hemodynamic assessment of the ophthalmic artery (OA) in the ocular ischemic syndrome (OIS) group, internal carotid artery stenosis (ICAS) group, and controls. (A) Schematic illustration of three-dimensional (3D) reconstruction of the OA and computational fluid dynamics (CFD) simulations. (B) Comparison of morphological and hemodynamic parameters at the OA origin among the three groups. In the blood flow panels, black arrows indicate flow direction, and percentages represent the OA/internal carotid artery (ICA) flow ratio. 3D, three-dimensional; CFD, computational fluid dynamics ICA, internal carotid artery; ICAS, internal carotid artery stenosis; OIS, ocular ischemic syndrome; OA, ophthalmic artery; *P < 0.05; **P < 0.01; ***P < 0.001; ns, not significant.

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  Figure 2.. The 3D printing of the OA and particle image velocimetry (PIV). (A) An anatomically accurate, high-transparency silicone phantom of the OA was created by 3D printing, based on the OA model used in the CFD simulations. (B) Schematic illustration of the PIV system, with the vascular model integrated into a custom-built closed-loop flow circuit (dashed line). (C) Qualitative comparison of the velocity fields obtained from PIV and CFD simulations in representative cases from the OIS and control groups. The PIV results showed good visual agreement with CFD simulations. PIV, particle image velocimetry.

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  Figure 3.. Representative cases of antegrade and retrograde OA flows in the OIS group. Both antegrade and retrograde flow patterns exhibit low wall shear stress at the OA origin.

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  Figure 4.. A representative OIS case with high-velocity retrograde OA flow. (A–C) Hemodynamics and diameter measurements at the OA origin. CFD simulation showing a retrograde flow velocity of 0.63 m/s and a wall shear stress of 3.77 Pa. (D) Fundus photograph. (E) Fundus fluorescein angiography (FFA, 12 minutes and 40 seconds after fluorescein injection) showing the arterial wall staining in the left eye, with no venous wall staining observed. (F, G) The lateral F and anteroposterior G DSA views demonstrating anastomoses between a branch of the left ophthalmic artery (OA) and branches of the ipsilateral superficial temporal artery (STA) and facial artery (FA), both originating from the external carotid artery system. (H, I) Optical coherence tomography (OCT) at 19-month follow-up I showing pronounced retinal thinning with ischemic macular edema compared with baseline H. FA, facial artery; FFA, fundus fluorescein angiography; ICA, internal carotid artery; OCT, optical coherence tomography; STA, superficial temporal artery.

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  Figure 5.. A representative OIS case with relatively slow retrograde OA flow. (A–C) Hemodynamics and diameter measurements at the OA origin. CFD simulation showing a retrograde flow velocity of 0.22 m/s and a wall shear stress of 3.01 Pa. (D) Fundus photograph. (E) FFA showing no evident arterial wall staining. (F–H) Color Doppler imaging demonstrated retrograde OA flow (waveform peaks below the zero-velocity baseline), whereas the central retinal artery and posterior ciliary artery maintained antegrade flow (waveform peaks above the zero-velocity baseline). (I, J) Optical coherence tomography (OCT) at the 7-year follow-up J showing no significant change in retinal thickness compared with baseline I.