Etiology
This condition results from chronic hypoperfusion, typically caused by carotid atherosclerosis, inflammatory vascular obstruction, or giant cell arteritis.
Clinical Manifestations
In the early stages, patients often report episodes of transient vision loss (amaurosis fugax), followed by intermittent ocular pain. In severe cases, progressive visual decline may occur. Fundus examination reveals narrowed retinal arteries and mild venous dilation with tortuosity. Scattered red, dot-like hemorrhages and microaneurysms are predominantly observed in the peripheral retina. Fluorescein Fundus Angiography (FFA) demonstrates delayed choroidal filling, marked prolongation of the arm-to-retina circulation time, and prolonged retinal circulation time. Ultra-widefield FFA frequently identifies peripheral retinal findings, including microvascular leakage, small vein abnormalities, and patchy non-perfused regions. Without timely intervention, most cases develop iris neovascularization, with elevated intraocular pressure occurring in about half of the cases. The development of iris neovascularization often leads to blindness due to neovascular glaucoma. Carotid Doppler ultrasound typically shows intimal thickening or atherosclerotic plaque formation at the bifurcation of the ipsilateral common carotid artery or the origin of the internal carotid artery. These findings include rough vessel wall surfaces, luminal narrowing, and, in severe cases, complete arterial occlusion.
Treatment
The primary approach focuses on treating the underlying systemic causes, such as carotid endarterectomy or carotid artery stenting. Panretinal photocoagulation and intravitreal injection of anti-vascular endothelial growth factor (VEGF) agents are beneficial in reducing anterior segment neovascularization. These treatments are often used as adjunctive methods for the prevention or management of neovascular glaucoma.