イデベノン大量投与療法を行い，光干渉断層計にて経時的変化を捉えたレーベル遺伝性視神経症の1例

A case of Leber hereditary optic neuropathy treated by massive dosis of idebenone and followed up by optical coherence tomography

要約　目的：イデベノンの大量投与を行ったレーベル遺伝性神経症の1例の報告。

症例：51歳男性が2週間前からの右眼の視力障害で受診した。

所見と経過：矯正視力は右0.04，左0.5であり，光干渉断層計で，両眼に視神経乳頭の耳側と下方の乳頭周囲網膜神経線維層の肥厚，右眼に神経線維層と神経節細胞層の菲薄化があった。ミトコンドリア遺伝子変異検査で11778変異があり，レーベル遺伝性神経症と診断した。コエンザイムQ₁₀の誘導体であるイデベノンの大量投与を6か月間行い，その6か月間の経過を追った。神経線維層と神経節細胞層は徐々に菲薄化し，矯正視力は左右眼とも0.02に低下した。ハンフリー視野はいったん増悪し，以後改善の傾向を示した。

結論：レーベル遺伝性神経症の診断と経過観察に，光干渉断層計による検査が有用であった。

Abstract　Purpose: To a case of Leber hereditary optic neuropathy treated by massive dosis of idebenone and followed up by optical coherence tomography.

Case: A 51-year-old male presented with impaired vision in the right eye since 2 weeks before.

Findings and Clinical Course: Corrected visual acuity was 0.04 in the right eye and 0.5 in the left. Coherence optical tomography（OCT）showed thickening of retinal nerve fiber layer temporal and inferior to the disc in both eyes. The right eye showed attenuation of retinal nerve fiber and ganglion layer, Mitochondrial DNA analysis showed 11778 mutation, leading to the diagnosis of Leber hereditary optic neuropathy. He was treated by massive dosis of peroral idebenone for 6 months. Follow-up for another 6 months showed further attenuation of retinal nerve fiber and ganglion layer. Visual acuity decreased to 0.02 in either eye. Humphrey visual field showed decrease followed by a tendency to improvement.

Conclusion: Follow-up with optical coherence tomography was useful in the present case of Leber hereditary optic neuropathy.