Monocular central retinal artery occlusion caused by bilateral internal carotid artery hypoplasia complicated with patent foramen ovale: a case report and review of literature

BACKGROUND: Central retinal artery occlusion (CRAO) is an emergent ophthalmic disease which is commonly caused by atherosclerosis, thromboembolism, and arteriospasm. Here, we report a case of CRAO which is caused by extreme rare bilateral internal carotid artery (ICA) hypoplasia complicated with patent foramen ovale (PFO). The cardiogenic emboli blocked central retinal artery through unclosed foramen ovale and specific blood flow pathway. CASE PRESENTATION: This report describes a case of a 46-year-old woman sudden onset with amaurosis fugax for about 20 min and persistent visual impairment of left eye. Fundus fluorescein angiography shows the arm-retinal circulation time of left eye is 25 s, indicating that the occlusion occurs in the pathway from aortic arch to ophthalmic artery. The MRA and CTA examinations reveal the bilateral ICA hypoplasia and variation of Wills circle. Furthermore, transesophageal echocardiography (TEE) confirms the PFO and cardiogenic embolic event. CONCLUSIONS: This work presents a CRAO case caused by rare congenital hypoplasia of ICA complicated with PFO, reminding us every single cause of vascular disease should be investigated carefully and the TOAST typing of cerebrovascular disease can be of great reference to the ocular vascular disease. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1186/s40001-021-00530-w.