The sphenoidal sinus in optic nerve decompression.

Surgical decompression of the orbit may be necessary in dysthyroid patients with compressive optic neuropathy. Two-wall decompression with a trans-antral or a trans-conjunctival approach is commonly used. However, in some patients the initial improvement following this surgical procedure is not maintained. Although this may be due to disease progression, a variant of orbital anatomy can contribute to sub-optimal decompression. We report three cases in which recurrence of compressive optic neuropathy occurred following two-wall decompression. The sphenoidal sinus was placed anteriorly in these patients. Further decompression which included the lateral wall of the sphenoidal sinus resulted in improvement. An endoscopic approach provides superior access and visibility for decompression of the optic nerve into the sphenoidal sinus, and this approach may be the surgical treatment of choice in these cases.