Abstract
Optic canal involvement in fibrous dysplasia of bone is relatively common though only 9 cases of surgical intervension have been reported.
A 49-year-old male complained of blurred vision and loss of visual acuity of the right eye with swelling of the right side of the forehead for one year. He had already been diagnosed as having fibrous dysplasia from right third rib biopsy 12 years before, and also from operation of pathological fracture of the right femoral neck 9 years later. On admission in June 1980, his visual acuity of the right eye was 0.04 though it had been 1.0 9 years earlier. No other neurological deficit were seen. Because of the progressive loss of vision, transfrontal decompression of the right optic canal was performed. Visual acuity gradually improved in the postoperative follow up period and about 2 years later, it was 0.5.
When loss of vision is progressive, transfrontal approach to unroof the optic canal seems indicated. The safe and steady way in operation seems to be careful dissection under the operating microscope using a high-speed airtome with a diamond tip. If the location of optic canal is hard to distinguish because of the thickened bone and tortuous elongation of the canal, the dura mater should be opened to detect the proximal end of the optic canal when begining unroofing.
