Introduction: High-grade internal carotid stenosis results in impaired flow dynamics in the ocular circulation that may lead to a rare clinical entity; ophthalmic ischemic syndrome (OIS). The aim of this study was to investigate hemodynamic changes in the ophthalmic circulation after carotid revascularization, assessed with duplex ultrasonography (DUS), and their potential impact on ocular function in patients suffering from OIS.
Evidence acquisition: A systematic review of the literature was performed according to the PRISMA guidelines. Medline, Embase and Central databases were searched.
Evidence synthesis: The analysis included fourteen cohort studies (589 patients) reporting on the hemodynamic effect of carotid revascularization on the ophthalmic circulation using DUS. Eighty-five per cent of patients were treated for symptomatic carotid stenosis. The pre- and postoperative ophthalmological evaluation was recorded in four studies (227 out of 358 patients [63%] diagnosed with OIS). Reversed ophthalmic artery (OA) flow prior to carotid revascularization was present in 86 cases (24%). Following carotid revascularization, a significant increase in peak systolic velocity (PSV) (mean difference [MD] 14.712 cm/s, 95% confidence interval [CI] 10.566-18.858, P<0.001, I2=96%) and a significant anterograde restoration of flow in the OA (OR: 2.047, 95% CI: 1.72-2.42, P<0.001, Ι2=0%) were recorded. Carotid revascularization resulted in regression of ischemic symptoms in 93.1% of patients (95% CI: 56.4-99.3%), P=0.001, I2=82%).
Conclusions: Carotid revascularization may be associated with a significant flow restoration and PSV increase in the OA; as well as clinical improvement in ischemic ophthalmic symptoms in patients with OIS.