Incidence and Risk Factors for Ocular Ischemic Syndrome in Patients with Complete Internal Carotid Artery Occlusion

Abstract Purpose Ocular ischemic syndrome could lead to irreversible blindness and death. To investigate the incidence of and risk factors for ocular ischemic syndrome in patients with complete internal carotid artery occlusion.Methods This retrospective study included 55 patients with complete internal carotid artery occlusion from January 2016 to January 2021 in our hospital. Ophthalmic evaluations and blood test results were recorded.Results Thirty-four (61.8%) eyes with homolateral complete internal carotid artery occlusion were diagnosed with ocular ischemic syndrome. Among the 34 first-visit cases in the Department of Ophthalmology, 32 were misdiagnosed with other ocular diseases. A lower D-dimer level (odds ratio = 0.007, 95% confidence interval: 0.000-0.182) was associated with the presence of ocular ischemic syndrome in patients with complete internal carotid artery occlusion.Conclusions Ophthalmologists should pay close attention to patients with complete internal carotid artery occlusion and suspected or confirmed ocular ischemic syndrome, especially those with lower D-dimer levels.