Surgical Treatment of Bilateral Optic Nerve Sheath Meningioma: 2-Dimensional Operative Video

Even though intracranial meningiomas commonly invade the optic canals, true optic nerve sheath meningiomas are extremely rare. They are insidious lesions that frequently grow in 4 stages, leading to progressive visual loss.1-4 Frequently, management includes observation for asymptomatic patients, and fractioned stereotactic radiotherapy with progressive visual loss.1,3 However, surgery is avoided due to the risk of perioperative visual loss.2-4 However, many of these cases present in the early stage of tumor growth, where an arachnoidal plane is still present, and vision can be saved by microsurgical tumor resection.2 Here we present the case of a 33-yr-old female presenting with a 3-wk history of blurred vision. Neuroimaging depicted an enhancing lesion along both optic nerves consistent with bilateral optic nerve sheath meningioma. Neuroophthalmological examination showed inferior cut of visual field bilaterally, more extensive on the left eye. Acuity was 20/20 on both eyes. Microsurgical resection of the tumor was performed through left supraorbital craniotomy, with the goal of eliminating intracranial extension and stabilizing visual function.5 The optic canal was unroofed with diamond bit drill under copious irrigation. A remarkable improvement of her visual field was observed with maintenance of acuity at 20/20 on follow-up. As the patient is attempting pregnancy, she is closely monitored without radiation. Surgery can be offered as a primary treatment of optic nerve sheath meningiomas, especially in early stages, with likely preservation and, in some cases, improvement of visual function.6 The patient consented to the procedure and the use of image. Images at 1:46 and 3:48 reprinted from Al-Mefty O, Operative Atlas of Meningiomas. 1998: Raven Press; Philadelphia, PA, with permission from LWW. Image at 2:57 reprinted from Rassi et al2; © Anil Can, 2018, used with permission. Image at 9:27 in public domain/age.