Optic nerve enlargement and chronic visual loss.

We present four patients with sarcoidosis of the anterior visual pathways. The first patient presented with unilateral visual loss, a mass lesion at the optic nerve head, and an enlarged orbital optic nerve. The second patient presented with bilateral progressive painless visual loss, associated with optic nerve pallor and visual field loss. In these two patients, optic nerve biopsy was diagnostic of sarcoidosis. The third patient developed optic nerve and chiasmal involvement after sarcoidosis was established by lacrimal gland biopsy. The fourth patient had optic nerve, pulmonary, and lymph node involvement with sarcoidosis. A conjunctival and lung biopsy were diagnostic. Computed tomography and magnetic resonance imaging have greatly facilitated diagnosis of sarcoidosis of the anterior visual pathways. Sarcoidosis of the anterior visual pathways may occur alone or in association with other ocular or systemic manifestations. A conjunctival or lacrimal gland biopsy may be preferable as the initial diagnostic approach. Treatment of patients with this condition may require systemic immunosuppression, in addition to corticosteroids, to prevent permanent visual loss.