Visual loss associated with choroidal nevi.

Twenty-two of 206 patients (11%) with choroidal lesions diagnosed clinically as nevi of the posterior fundus had decreased visual acuity attributable to the lesion. The decreased visual acuity was secondary to serous foveal detachment (50%), presumed photoreceptor degeneration without serous detachment (42%), and subretinal choroidal neovascularization overlying the nevus (8%). Visual loss associated with a small melanotic choroidal tumor does not necessarily imply that the tumor is a choroidal malignant melanoma as 88% of the small melanotic choroidal tumors causing visual impairment did not grow during an average follow-up period of 25 months, and the great majority of these tumors were probably true spindle cell nevi. However, three tumors (12%), initially categorized as "suspicious nevi," enlarged during follow-up and were recategorized as malignant melanomas.