Optic Nerve Sheath Meningioma: A Case Report

Introduction: The clinical manifestations of optic nerve sheath meningiomas may mimic other orbital or neurological conditions, particularly in asymptomatic patients. This may result in misdiagnosis or delayed treatment, resulting in permanent vision loss. This case report highlights multimodal imaging findings and the clinical outcome of a patient with an optic nerve sheath meningioma. Case Report: A 71-year-old Caucasian male presented for a routine eye exam. Ocular examination revealed near-normal visual acuity for both eyes. Fundus examination showed indistinct cupping and indistinct disc margins in the right eye. Optical coherence tomography was performed verifying an edematous right optic nerve. Fundus autofluorescence did not reveal any optic disc drusen in either eye. Color vision testing was reduced in the right eye compared to the left. Additionally, formal automated visual field testing showed an inferior nasal step defect in the right eye and a clean visual field without defects in the left eye. Laboratory testing placed giant cell arteritis lower on the differential list. Computerized tomography of the head and orbits without contrast indicated the presence of a mass in the right optic nerve. Magnetic resonance imaging with contrast of the head and orbit was performed confirming the diagnosis of an optic nerve sheath meningioma. Conclusion: Optic nerve sheath meningiomas typically cause vision loss and/or diplopia; however, not all patients are symptomatic. Multimodal imaging can aid in the diagnosis of optic nerve sheath meningiomas, allowing for faster diagnosis, treatment, and possibly improved prognosis.