圧迫性視神経症をきたした巨大頸動脈瘤の1例

Compression optic neuropathy in a case of giant carotid aneurysm

要約　36歳男性が2か月前からの右眼の視力低下と視野異常で来院した。矯正視力は右30cm指数，左0.7で，右眼に視神経萎縮があり，RAPD（relative afferent pupillary defect）が陽性であった。脳血管造影などで30×25mm大の右側巨大内頸動脈瘤があった。まず総頸動脈結紮術，ついで内頸動脈結紮術を行い，動脈瘤は縮小した。これとともに，視力と視野は改善し，初診から27か月の現在，右0.09，左1.2の視力を得ている。経過中に，両眼の視力と視野に経時的な変動があった。これは，巨大動脈瘤による視神経圧迫のほかに，微小循環障害や視神経の栄養血管の虚血性障害の関与があるためと推定した。

Abstract.　A 36-year-old male presented with impaired vision and visual field in his right eye since 2 months before. His corrected visual acuity was 30 cm counting fingers right and 0.7 left. The right eye showed optic atrophy and positive RAPD（relative afferent pupillary defect）. A giant right carotid aneurysm,30×25 mm in size,was detected by cerebral angiography. The aneurysm eventually reduced in size after ligation of common carotid followed by ligation of internal carotid. The visual acuity and field improved thereafter. His visual acuity is 0.09 right and 1.2 left 27 months after his initial visit. Both eyes showed fluctuations in visual acuity and field during the course of the desease,probably due to impaired circulation in the optic nerve in addition to compression of the optic nerve by the giant aneurysm.