Figure 1.

Axial magnetic resonance image of the left eye in adduction. The terminal cross-sectional areas of the MR and LR near the orbital apex and insertions onto the globe (enclosed dashed rectangles) could not be directly measured on coronal imaging. Volumes within these regions were estimated by dividing the segments of unresolvable cross sections into 2-mm slices (thin dashed lines). The number of slices required to span the terminal segments was multiplied by the terminal measured cross-sectional areas and then by the 2-mm slice thickness. ON, optic nerve.