Other associated risk factors include smoking, optic disc drusen, optic disc edema, hypercoagulable state (polycythemia, multiple myeloma, cryoglobulinemia, Waldenström macroglobulinemia, antiphospholipid syndrome, Leiden factor V, activated protein C resistance, hyperhomocysteinemia, protein C and S deficiency, antithrombin III mutation, prothrombin mutation), syphilis, sarcoidosis, African American race, sickle cell disease, human immunodeficiency virus (HIV), vasculitis, drugs such as oral contraceptives or diuretics, abnormal platelet function, orbital disease, and rarely migraines [12]. Here, F2 is linked to sickle cell disease.