Optic nerve decompression in cranial base fibrous dysplasia.

Fibrous dysplasia of the anterior cranial base involves the bony orbit and optic canal. Although fibrous dysplasia is benign, it may produce a mass effect along the course of the optic nerve, inducing visual disturbances. Optic canal decompression in patients without clinical signs of optic neuropathy is controversial. We describe five patients with extensive fibrous dysplasia of the anterior cranial base involving the orbit and optic canal. These patients underwent transcranial optic canal decompression before signs of severe visual loss during correction of dystopias and craniofacial deformity induced by fibrous dysplasia. Cranial orbital reconstruction was performed by means of split rib and cranial bone grafts. Postoperative follow-up did not reveal disturbances in visual function, extraocular motility, or evidence of cerebrospinal fluid fistulas. This suggests that early, radical resection of orbital fibrous dysplasia with optic canal decompression may be effective in preventing visual loss with minimal risk of other neurological sequelae. Subsequent orbital reconstruction involving split-thickness rib and cranial bone grafting yields satisfactory cosmetic results.