Internal Carotid Artery Ligation: A Murine Model for Acute Retinal Ischemic Injury.

Accumulating evidence indicates that retinal ischemia constitutes a pivotal pathological trigger of visual impairment. The cerebral arterial circle (circle of Willis), formed by the vertebral and internal carotid arteries, provides cerebral blood perfusion. As a direct branch originating from the internal carotid artery (ICA), the ophthalmic artery supplies blood to the ocular globe. Based on the anatomical features of the ocular vasculature, a retinal ischemic injury model was successfully generated in C57BL/6 mice via selective left ICA ligation. Morphological and vascular analyses demonstrated marked lesions largely confined to the intermediate retinal vascular plexus. Histological and immunohistochemical staining revealed that the counts of bipolar cells and retinal ganglion cells in the superficial and intermediate retinal layers were markedly reduced. At the molecular level, this retinal ischemia model effectively activates a complex cascade of intracellular signaling pathways that govern apoptosis, inflammatory response, oxidative stress, angiogenesis, and neuronal injury regulation. The retinal ischemic injury model established by ICA ligation offers advantages, including high safety and ease of operation for targeted lesion modeling. In addition, this acute retinal ischemic injury model circumvents systemic circulatory disorders induced by the widely used common carotid artery (CCA) ligation method. This model facilitates a comprehensive exploration of the pathological mechanisms behind retinal ischemic disorders induced by hemodynamic abnormalities of the ophthalmic artery.