長期観察が可能であった特発性網膜動脈分枝閉塞症の1例

Long-term clinical course of a case with idiopathic branch retinal artery occlusion

要約　目的：特発性網膜動脈分枝閉塞症（Susac症候群）の5年以上の経過についての報告。

症例：37歳女性。左眼の視野障害を自覚し受診した。既往歴として10歳時より頭痛がある。17歳時に特発性網膜動脈分枝閉塞症と診断され，その後何回も再発している。

結果：両眼とも矯正視力は1.0。右眼には網膜動脈分枝間で側副血行路を認めた。経過観察中に特発性網膜動脈分枝閉塞症を数回認めたが，いずれも網膜白濁は軽度であった。網膜厚カラーマップ，ganglion cell complexともに検眼鏡で確認した閉塞部以外にも菲薄化が認められた。

結論：発症より25年の間に網膜動脈分枝閉塞症の再発と，多発を繰り返した。特発性網膜動脈分枝閉塞症の陳旧期の眼底所見は一見正常に見えるが，光干渉断層計で網膜厚，ganglion cell complexを測定すると，検眼鏡的に閉塞を確認した部位以外に閉塞が起きた部位が確認できた。

Abstract　Purpose: To report the clinical course of a case with idiopathic branch retinal artery occlusion（Susac syndrome）over a 5-year period.

Case: A 37-year-old woman presented with visual field defect in the left eye. She had had attacks of migraine since the age of 10 years. She was diagnosed with idiopathic branch retinal artery occlusion in both eyes at the age of 17 years, followed by recurrences.

Findings: Corrected visual acuity was 1.0 in either eye. The right eye showed arterio-arterial collaterals. She showed recurrences of idiopathic branch retinal artery occlusion during the ensuing 5 years. Retinal opacity was mild after each recurrence. Multiple retinal areas showed thinning within and outside of retinal artery occlusion when observed by optical coherence tomography（OCT）regarding retinal thinning and ganglion cell complex.

Conclusion: The present case has had repeated recurrences of idiopathic branch retinal artery occlusion in both eyes in the past 25 years. Retinal thinning, including the ganglion cell complex, was present in areas in and outside of areas involved by branch retinal artery.