A patient with neurofibromatosis type 1 had pulsating exophthalmos of the right eye with diplopia resulting from severe dysplasia of the sphenoid bone and consecutive herniation of the right temporal lobe. The right orbital tectum was reconstructed with titanium mesh and iliac spongiosa via a lateral orbitotomy using intraoperative navigation. For intraoperative referencing a cortical fixed-reference system and a skin scanning laser device were used. Postoperatively, the diplopia was reduced, but the patient asked for further treatment and the procedure was repeated 6 months later. Intraoperatively, the previously implanted titanium mesh was deformed and most of the transplanted bone was resorbed, probably because of pressure. A more extended mesh was implanted and iliac spongiosa was placed on both sides. Intraoperative navigation was used during both procedures. The adverse effects of diplopia were minimized and follow-up computed tomography after seven months confirmed that the bone graft was in place.
