Endoscopic Optic Nerve Decompression for Optic Neuropathy in Sinonasal Fibro-Osseous Tumors

Background: Sinonasal fibro-osseous tumors involving the skull base sometimes result in the encasement of the optic canal and can cause the compressive optic neuropathy. This study aimed to elucidate the optimal timing of endoscopic optic nerve decompression (OND) in cases with optic neuropathy caused by fibro-osseous tumors. Methods: Medical records were reviewed retrospectively from July 2008 through November 2016. Subjects who underwent surgery with endoscopic OND for optic neuropathy caused by fibro-osseous lesions were enrolled. Pre- and postoperative ophthalmologic evaluation were analyzed, including best-corrected visual acuity, visual field testing, and color vision. Results: A total of 9 patients underwent OND. Seven patients had fibrous dysplasia and 2 patients had juvenile ossifying fibroma. Patients included 6 boys and 3 girls. The average age was 15 years with a range of 8–17 years. Symptom duration ranged from 2 months to 4 years. The mean follow-up period was 28 months (range, 0.8–76.4 months). There was no immediate deteriorated vision after OND. Eight eyes (88.9%) were improved and 1 eye (11.1%) had only visual field improvement. However, patients whose visual impairment was in the range of finger count and hand motion were not recovered beyond the quantitatively measurable level even after OND. Conclusions: Endoscopic OND in patients with optic neuropathy caused by a fibro-osseous tumor in the sinonasal region is safe and worth trying to improve visual outcomes. Early therapeutic OND is recommended before the patient's visual function is decreased below quantitatively measurable vision.