After exclusion of poor‐quality OCTA images, 83 patients with MS (146 eyes; 76 with ON and 70 without ON), 91 patients with AQP4‐IgG‐seropositive NMOSD (135 eyes; 90 with ON and 45 without ON), and 34 HCs (68 eyes) were enrolled. Here, AQP4 is linked to myeloid sarcoma.