Isolated metastases to the retina or optic nerve.

Isolated metastases to the retina or optic nerve are extremely rare. Retinal metastases arise from cutaneous malignant melanoma and carcinomas (lung, gastrointestinal, genitourinary, and breast). Most patients present with reduced vision. The clinical appearance of these metastases is variable. Melanoma metastases are brown or black, whereas carcinoma metastases are white. Frequently, retinal hemorrhages and exudates are seen. Optic nerve metastases arise from carcinomas (lung, breast, and gastrointestinal) in adults and acute leukemias in children. As is true of retinal metastases, most patients present with reduced vision. Though in most cases there is a visible optic nerve mass, some patients have optic disc edema only. Investigations are directed by a known history of malignancy in many patients and by physical examination. Cytological workup of vitreous may be required. Treatment options include observation, radiotherapy in eyes with visual potential, and enucleation for pain control. The visual prognosis is poor. In patients with retinal or optic nerve metastases, median survival is approximately 9 months after the onset of visual symptoms, but is slightly longer in cases in which the primary lesion is breast carcinoma.