Fig 1.

Coronal fat-saturated T2-weighted orbital MR images of cases 1, 2, and 3. In case 1, MR images showing the subarachnoid space (arrow) had collapsed and the ONS could not be detected before treatment (A) but became visible with diameter of 5.5 mm on the right and 5.8 mm on the left after treatment (B). In case 2, MR images showing the ONS diameter just behind the optic globe before treatment were 5.0 mm on the right and 4.7 mm on the left (C) and became 5.9 mm and 5.3 mm, respectively, after treatment (D). In case 3, MR images showing the subarachnoid space had collapsed, and the ONS could not be detected before treatment (E) but became visible with a diameter of 6.2 mm on the right and 6.2 mm on the left after treatment (F).