ABSTRACT
Occlusions in the retina are caused by a physical blockage in the circulatory system of the eye and/or the retina specifically. The retina is particularly sensitive to occlusions, or physical obstructions in the circulation caused by an embolus, because of its nonfenestrated structure. Emboli cause occlusions in the arterial circulation of the retina. They result from a free floating obstruction or plaque entering retinal circulation and causing an acute blockage. Occlusions in the retina come in two versions in the system: central and branch. Central occlusions block the main vessel that takes blood to and from the retina; either the central retinal artery or the central retinal vein. Branch occlusions occur at a branch of either a vein or artery, and they usually have all the signs and symptoms of a central occlusion but confined to a single quadrant or area.
