[Sarcoidosis of the anterior optic pathways. A diagnostic discussion]

Two anatomo-clinical cases of neuro-ophthalmic sarcoidosis are reported where recognition of systemic involvement was delayed because unusual and quite isolate visual symptoms were present. The first patient had granulomas involving the intracranial optic nerve, presenting as optic nerve glioma. The second case presented as a chiasmal syndrome sharing unusual perimetric evolution. This binasal hemianopsia was probably the consequence of pre-chiasmal circulatory changes. Neuro-ophthalmic sarcoidosis should be included in the differential diagnosis of any involvement of the anterior visual pathways since these localizations are not as rare as was formerly thought. Improved awareness of this condition is a result of better neurodiagnostic studies by computed tomography which was not accurate enough a few years ago.