PMC5244282_01
Large left sphenoidal sinus with Onodi cell-like projections (above, red arrow) on the left optic canal (below, left); Left Onodi air cell (white arrow) impinging on the left optic nerve.
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F1
An axial plane of contrasted CT of the orbit demonstrated a big left sphenoid sinus (Fig. 1) with Onodi-cell-like projection on the left superior margin of the left optic canal, which impinged on the left optic nerve (Fig. 1).
Superior wall of the left sphenoid sinus dehiscence.
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F2
The coronal plane of the CT orbit (Fig. 2) revealed thinning of the superior wall of the left sphenoid sinus adjacent to the left optic nerve.
Intraoperative endoscopic view of left optic nerve decompression.
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F3
The medial part of the optic nerve wall was opened (Fig. 3), and surgery proceeded without any complications.