Retinal Artery Occlusion

Retinal artery occlusions (RAO) are characterized by the sudden obstruction of the arterial blood flow in the retinal circulation with consequent ischemic damage to the retina. RAO can be subdivided into several forms, including central retinal artery occlusion (CRAO) and Branch retinal artery occlusion (BRAO). Patients affected by CRAO experience a sudden, monocular loss of vision. On fundus biomicroscopy, if the retinal obstruction is incomplete a slight gray haze may be visible, but when the flow blockage is complete a progressive whitening and swelling of the inner retina develops. Patients affected by BRAO complain of sudden, partial or complete, visual loss associated with visual field damage. The area concerned by the BRAO shows evidence of acute retinal ischemia corresponding to the distribution of the occluded branch retinal artery. At present, there is no generally agreed treatment regimen for RAO, although a number of therapeutic interventions have been proposed. Copyright © 2012 S. Karger AG, Basel Retinal Artery Occlusions Definition Retinal artery occlusions (RAO) are a group of diseases characterized by the sudden obstruction of the arterial blood flow in the retinal circulation with consequent ischemic damage to the retina [1]. Classification According to the involved vessels, RAO can be subdivided into several forms, including: • Central retinal artery occlusion (CRAO). • Branch retinal artery occlusion (BRAO). • Cilioretinal artery occlusion. • CRAO sparing cilioretinal artery. • CRAO associated with CRVO. • Ophthalmic artery occlusion. The two main forms are central retinal artery occlusion and branch retinal artery occlusion. Etiology The etiology of RAO encompasses many conditions, as summarized in table 1. Table 1. Etiology of RAO