Unusual case of melanocytoma in optic disk.

An unusual case of melanocytoma in the optic disk was reported. At the initial examination, unilateral papilledema and irregular concentric contraction of the visual field with fair vision were observed. In the follow-up study, central retinal artery occlusion occurred and vision deteriorated to blindness. Subsequently, a darkly pigmented lesion appeared and enlarged slowly during the period of 14 years. The pathogenesis of visual disturbance caused by the melanocytoma was discussed.