Ocular Ischemic Syndrome
Ocular ischemic syndrome results from hypoperfusion of the entire eye and sometimes the orbit, usually because of carotid artery obstruction. Patients with ocular ischemic syndrome are typically men aged 65 years or older. Patients present with decreased vision and mild ocular pain. Examination findings may include corneal edema, anterior chamber cells, and moderate flare, the last often greater than and out of proportion to the number of cells. Anterior segment neovascularization may be present. Intraocular pressure may be low from decreased aqueous production due to ischemia or high due to neovascular glaucoma. A cataract may be more prominent on the involved side. The vitreous is usually clear. Dilated fundus examination may show mild disc edema associated with dilated tortuous retinal venules, narrowed arterioles, and medium to large intraretinal scattered blot hemorrhages in the midperiphery and far periphery of the retina. Neovascularization may be present on the disc or elsewhere in the retina.
Fluorescein angiography shows delayed arteriolar filling, diffuse leakage in the posterior pole as well as from the optic disc, and signs of capillary nonperfusion. Retinal vascular staining may be present in the absence of any physical vascular sheathing on examination.
Diagnostic studies include carotid Doppler ultrasonography; ipsilateral carotid stenosis greater than 90% supports the diagnosis of ocular ischemic syndrome.
Definitive treatment involves carotid endarterectomy. Local treatment consists of topical corticosteroids and cycloplegics, as well as panretinal photocoagulation, especially if rubeosis or retinal neovascularization is present. Intraocular injection of vascular endothelial growth factor (VEGF) inhibitors may also be considered. The 5-year mortality rate of patients with ocular ischemic syndrome is 40%, primarily from cardiovascular disease and myocardial infarction. The visual prognosis is guarded, and many patients improve transiently with treatment but eventually worsen.
Excerpted from BCSC 2020-2021 series: Section 9 - Uveitis and Ocular Inflammation. For more information and to purchase the entire series, please visit https://www.aao.org/bcsc.