Optic nerve involvement as the initial manifestation of sarcoidosis.

Sarcoidosis is a multisystem granulomatous disease of unknown cause. It may have several diverse manifestations that may be progressive yet develop slowly. Ocular disease may occur with inactive systemic disease. We describe two patients in whom optic nerve involvement was the first manifestation of sarcoidosis and clinically mimicked an optic nerve tumour. Sarcoidosis involving the optic nerve should be considered when an optic nerve tumour is suspected.