スペクトラルドメイン光干渉断層計でうっ血乳頭を定量評価した特発性頭蓋内圧亢進症の1例

Quantitation of papilledema by spectral domain optical coherence tomography in a case of idiopathic intracranial hypertension

要約　目的：スペクトラルドメイン光干渉断層計（SD-OCT）でうっ血乳頭の経過を定量評価した特発性頭蓋内圧亢進症の症例の報告。症例：38歳女性が1週前からの左眼の飛蚊症と頭痛で受診した。所見：視力は両眼1.2，両眼にMariotte盲点の拡大およびうっ血乳頭を認めた。MRIで頭蓋内に占拠性病変はなかった。髄液圧は400mmH₂Oと亢進し，特発性頭蓋内圧亢進症と診断した。SD-OCTによる乳頭浮腫面積の定量値は，治療前右11.3mm²，左12.9mm²。アセタゾラミド内服治療後，早期より乳頭浮腫面積は減少し，3か月後には右2.2mm²，左3.8mm²であった。結論：SD-OCTによるうっ血乳頭の定量評価は，特発性頭蓋内圧亢進症の治療効果を非侵襲的かつ客観的に評価するのに有用であった。

Abstract.　Purpose：To report a case of idiopathic intracranial hypertension followed up by quantitation of papilledema using spectral domain optical coherence tomography（OCT）. Case：A 38-year-old female presented with headache and floaters in the left eye since one week before. Findings：Visual acuity was 1.2 in either eye. Both eyes showed papilledema with enlarged blind spot. Magnetic resonance imaging（MRI）failed to show space-occupying lesion in the cranium. Cerebrospinal fluid pressure was 400 mmH₂O, leading to the diagnosis of idiopathic intracranial hypertension. Spectral domain OCT showed the area of papilledema to be 11.3 mm² in the right eye and 12.9mm² in the left. Papilledema decreased following systemic treatment with acetazolamide. Area of papilledema was identified as 2.2 mm² right and 3.8 mm² left 3 months of treatment. Conclusion：Spectral domain OCT was non-invasive and useful in quantitative evaluation of papilledema in a case of idiopathic intracranial hypertension.