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 di sturbances. Optic canal decompression in patients without clinical sig ns of optic neuropathy is controversial. We describe five patients wit h extensive fibrous dysplasia of the anterior cranial base involving t he orbit and optic canal. These patients underwent transcranial optic canal decompression before signs of severe visual loss during correcti on of dystopias and craniofacial deformity induced by fibrous dysplasi a. Cranial orbital reconstruction was performed by means of split rib and cranial bone grafts. Postoperative follow-up did not reveal distur bances in visual function, extraocular motility, or evidence of cerebr ospinal fluid fistulas. This suggests that early, radical resection of orbital fibrous dysplasia with optic canal decompression may be effec tive 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.