“…When a direct CCF is formed, arterial blood enters the cavernous sinus at high pressure; it can cause blood flow reversal and interferes with normal venous return to the cavernous sinus [ 1 ], dilatation of the upstream venous network with arterialization is observed [ 9 , 10 ]. Such venous flow can affect the ophthalmic vein, leading to orbital congestion, and manifestations such as proptosis, ophthalmic fremitus or bruit and chemosis [ 1 ]. The perfusion pressure of the ophthalmic artery is simultaneously reduced, which causes retinal ischaemia and visual disturbances [ [1] , [2] , [3] ].…”