Neuro‐ophthalmological analysis and imaging of optic nerve tumours

Abstract

Abstract Purpose: To describe correlations between the clinical manifestations and the neuro‐radiological features of optic nerve tumors. Methods: Description of the available radiological techniques for the appropriate evaluation of an optic nerve tumor. MR imaging of the orbit is the most common method and it should include standard enhanced fat‐suppression, T1 and T2‐weighted axial and coronal images, other sequences being optional. Results: The two most primary common optic nerve tumors are optic nerve glioma and optic nerve meningioma, other tumors (gangliogliomas, medulloepitheliomas, haemangioblastomas haemangiopericytomas, etc.) being more rare, diagnosed on pathological, not radiological grounds.Optic nerve meningiomas, occurring most commonly in middle‐aged females, have a tubular appearance on CT or MR as opposed to the fusiform or globular shape of optic gliomas. Optic nerve sheath meningiomas are usually isointense or hypointense on T1‐weighted imaging, enhancing after contrast injection.Metastatic carcinomas to the optic nerve are very unusual, and may be sometimes radiographically indistinguishable from optic nerve meningioma. In most of the cases a thourough history and accurate clinical examination may help the interpretation of the radiological findings, pathology being however at times necessary in atypical cases. Conclusions: Neuro‐imaging allows most often to distinguish different types of optic nerve tumors. This is the reason why it is widely accepted now to use radiotherapy for treatment of optic nerve sheath meningiomas without pathological confirmation of the diagnosis. In individual cases with atypical clinical or radiological features, pathology is nevertheless needed for firm diagnosis.