単独放射線療法が奏効した，ステロイド療法により全身合併症を生じた特発性外眼筋炎の1例

Radiation was effective in a case of idiopathic orbital myositis with systemic manifestations of pulsed steroid therapy

要約　目的：ステロイドパルス療法で重篤な全身合併症が生じ，放射線療法で軽快した特発性外眼筋炎の症例の報告。症例：61歳女性が複視と左眼の下転障害で受診した。磁気共鳴画像検査で両眼の外眼筋に肥厚があり，特発性外眼筋炎と診断した。総量6gのメチルプレドニゾロンのパルス療法で肝機能障害，耐糖能異常，胃びらんが生じた。眼痛と外眼筋腫脹の悪化に対し，両側の眼窩への放射線療法を総量20Gy，10分割で開始した。眼瞼腫脹と眼球突出は改善し，外眼筋腫脹も軽減した。以後30か月後の現在まで再発はない。結論：ステロイドパルス療法が副作用のために実施できない特発性外眼筋炎には，放射線による単独治療が奏効することがある。

Abstract.　Purpose：To report a case of idiopathic orbital myositis that responded to external radiation after systemic corticosteroid had to be discontinued due to complications. Case：A 61-year-old female presented with diplopia and restricted downward gaze of the left eye. Magnetic resonance imaging（MRI）showed hypertrophy of bilateral external ocular muscles and led to the diagnosis of idiopathic orbital myositis. Pulsed methylprednisolone totaling 6 g resulted in impaired liver function,abnormal glucose level,and gastric ulcer. Swelling of extraocular muscles with ocular pain was the treated by radiation to both orbits totaling 20 Gy in 10 divided sessions. Proptosis and eyelid swelling disappeared with improved findings of swelling of extraocular muscles. There has been no recurrence for 30 months until present. Conclusion：This case illustrates that external radiation may be useful for idiopathic orbital myositis after systemic corticosteroid had to be discontinued.