Ocular Ischemic Syndrome

Ocular ischemic syndrome (OIS) is defined as the ocular manifestations of severe carotid artery stenosis or occlusion. For some patients, the first indication of carotid disease is OIS. Diagnosing a patient with OIS gives them a poor prognosis for both ocular and systemic morbidity, but may provide the physician with an opportunity to prevent a major stroke (Sivalingam et al. 1989, 1991). Since OIS was first described in 1963 (Hedges 1963; Kearns and Hollenhort 1963), imaging techniques have evolved, improving our ability to characterize the ocular findings of this disease. Although other authors have used the term venous stasis retinopathy, we will use the term ocular ischemic syndrome in this chapter (Brown et al. 2018).