Purpose To report clinical variations and the natural course of melanocytoma o f the optic disc. Patients and methods A retrospective study was conducted on a consecutive series of patients with melanocytoma of the optic disc who were evaluated at the Ocular Oncology Service at Wills Eye Hospital. Demographic information and variations i n appearance and size of the tumor and local ocular complications were noted. Fr equency of tumor growth and malignant transformation was recorded. Clinical fact ors, including patient data and tumor features, were analyzed for their impact o n visual acuity loss of 2 or more Snellen lines and the tumor growth, using Cox proportional hazards regression models. Kaplan-Meier survival estimates of prob ability of visual acuity loss of 2 or more Snellen lines and probability of tumo r growth were performed as a function of time from the initial examination. Main outcome measures Visual acuity loss of 2 or more Snellen lines, tumor growth, a nd malignant transformation of the tumor. Results There were 115 patients (116 e yes) with melanocytoma of the optic disc. The mean age at diagnosis was 50 years ; 38%of patients were male and 62%of patients were female; 65%of patients wer e white, 29%of patients were African American, and 6%of patients were Asian, H ispanic, Indian, or Arabic. The lesion was unilateral in 99%of patients. Visual symptoms that seemed to be related to the melanocytoma were present in 24%of p atients, and an afferent pupillary defect was noted in 9%of patients. Associate d ocular abnormalities included ocular melanocytosis (8%), racial melanosis (7 %), optic nerve hypoplasia (2%), and retinitis pigmentosa (1%). The melanocyt oma was dark brown to black in 100%of patients. The mean tumor diameter was 2 m m and the mean thickness was 1 mm. Associated findings included a choroidal comp onent (54%), retinal component (30%), optic disc edema (25%), retinal edema ( 16%), localized subretinal fluid (14%), retinal exudation (12%), retinal hemo rrhage (5%), vitreous seeds (4%), and retinal vein obstruction (3%). Fluoresc ein and indocyanine green angiography typically showed persistent hypofluorescen ce of the lesion. Using Kaplan-Meier survival curves, related visual loss occur red in 18%of patients by 10 years, and minor tumor enlargement occurred in 11% of patients by 5 years and in 32%of patients by 10 years. Malignant transformat ion was documented in 2 patients (2%). Conclusions Although melanocytoma of the optic disc generally is considered to be a benign, stationary lesion, it can pr oduce several local complications, can cause visual loss, can grow slowly, and, rarely, can undergo malignant transformation into melanoma. Patients with optic disc melanocytoma should undergo periodic ocular examination. Purpose To report clinical variations and the natural course of melanocytoma of the optic disc. Patients and methods A retrospective study was conducted on a consecutive series of patients with melanocytoma of the optic disc who were evaluated at the Ocular Oncology Service at Wills Eye Hospital. Demographic information and variations in appearance and size of the tumor and local ocular complications were noted. Fr equency of tumor growth and malignant transformation was recorded. Clinical fact ors, including patient data and tumor features, were analyzed for their impact on visual acuity loss of 2 or more Snellen lines and the tumor growth, using Cox proportional hazards regression models. Kaplan-Meier survival estimates of prob ability of visual acuity loss of 2 or more Snellen lines and probability of tumo r growth were performed as a function of time from the initial Main outcome measures Visual acuity loss of 2 or more Snellen lines, tumor growth, a nd malignant tr There are 115 patients (116 e yes) with melanocytoma of the optic disc. The mean age at diagnosis was 50 years; 38% of patients were male and 62% of patients were female; 65% of patients wer e white, 29% of patients were African American, and 6% of patients were Asian, H ispanic, Indian, or Arabic. The lesion was unilateral in 99% of patients. Visual symptoms that seemed to be related to the melanocytoma were present in 24% of pates, and an affection of pupillary defect was noted in 9% of patients. Associate d ocular abnormalities included ocular melanocytosis (8%), racial melanosis (7%), optic nerve hypoplasia (2%), and retinitis pigmentosa The mean tumor diameter was 2 mm and the mean thickness was 1 mm. Associated Diagnosis included a choroidal comp onent (54%), retinal component (30% ), optic disc edema (25%), retinal edema (16%), localized subretinal fluid (14%), retinal exudation%), retinal hemo rhage (5%), vitreous seeds (4%), and retinal vein obstruction (3%). Fluoresc ein and indocyanine green angi an outline persistent hypofluorescen ce of the lesion. Visual loss occur red in 18% of patients by 10 years, and minor tumor enlargement occurred in 11% of patients by 5 years and in 32% of patients by 10 years. Although melanocytoma of the optic disc generally is considered to be a benign, stationary lesion, it can pr oduce several local complications, can cause visual loss, can grow slowly, and, rarely, can, undergoible malignant transformation into melanoma. Patients with optic disc melanocytoma should undergo periodic ocular examination.