視野異常を伴った視神経乳頭黒色細胞腫の2例

Two cases of optic disc melanocytoma with visual field defect

要約　目的：視野異常を伴う視神経乳頭黒色細胞腫の2例報告。

症例：症例1は45歳，女性。右眼の乳頭鼻下側に約2/3乳頭径大の黒色腫瘤を認め，ゴールドマン視野検査（GP）では，マリオット盲点拡大と鼻上側視野狭窄を認めた。症例2は32歳，男性。左眼の乳頭下鼻側に約1乳頭径大の黒色腫瘤を認め，GPでは鼻側に軽度視野狭窄を認めた。2例とも視神経乳頭黒色細胞腫と診断し経過観察を行ったが，眼底，視野とも変化を認めなかった。

結論：2症例の病変部位はいずれも乳頭鼻側であったが，視野異常は鼻側に生じていた。本疾患では視野異常と腫瘍部位との間には特に明確な関係はないとする報告がみられるが，今回もそれを支持する結果であった。

Abstract　Purpose：To report two cases of optic disc melanocytoma with paradoxical visual field defect.

Cases and Findings：One was a 45-year-old female with visual acuity of 1.2 in either eye. A black tumor mass, about two-thirds of disc diameter, was present inferior nasal to the optic disc. Goldmann perimetry showed enlarged blind spot with narrowing of visual field in the nasal superior quadrant. The other was a 32-year-old male with visual acuity of 1.2 right and 1.0 left. A black tumor mass, about one disc diameter, was present nasal to the optic disc in the left eye. Goldmann perimetry showed narrowing of visual field in the nasal sector. These two cases were diagnosed with melanocytoma of optic disc. There has been no change in the appearance or visual field in both cases after follow-up for 3 and 4 years respectively.

Conclusion：Narrowing of visual field did not match the location of melanocytoma adjoining the disc. This finding seems to suggest the absence of clear etiological relation between the location of melanocytoma and visual field defect.