Simultaneous Ischemic Superior Hemicentral Retinal Vein Occlusion and Nonischemic Inferior Hemicentral Retinal Vein Occl

Frame from the fluorescein angiogram of a 74 year old patient with an unambiguous, severely ischemic superior hemicentral retinal vein occlusion and a simultaneous less ischemic inferior hemicentral retinal vein occlusion. The yellow arrow denotes an arteriovenous shunt vessel that does not supply intervening capillaries that are closed. The red arrow denotes an analogous vessel that connects a superior arteriole with an inferior venule, an early manifestation of an intraretinal collateral vessel that shunts venous drainage to the less severely obstructed inferior venous system. Although this patient would be classified as having a central retinal vein occlusion, in fact the patient has dual, simultaneous hemicentral retinal vein occlusions. The risk factors and treatment considerations would be the same in either case.