片眼の硝子体出血と虹彩ルベオーシスで発見された内頸動脈循環不全の1例

A case of stenosis of internal carotid artery with unilateral vitreous hemorrhage and rubeosis iridis as the initial clinical manifestation

69歳男性が左眼硝子体出血で紹介受診した。9年前から糖尿病があった。矯正視力は右0.4，左手動弁で，右眼に単純糖尿病網膜症，左眼に虹彩ルベオーシスと硝子体出血があった。眼内循環の左右差が大きいことから，全身検索で左内頸動脈の狭窄が発見された。これに対してステント留置術が行われ，その9日後に虹彩ルベオーシスは消退していた。左眼の硝子体出血に対し硝子体手術が行われ，矯正視力は0.3に改善した。糖尿病網膜症で眼内虚血の左右差が大きい場合は，眼外の循環不全が関与している可能性がある。

A 69-year-old male presented with vitreous hemorrhage in his left eye. He had been diagnosed with diabetes mellitus 9 years before. His corrected visual acuity was 0.4 right and hand motion left. The right eye had simple diabetic retinopathy. The left eye had rubeosis iridis and vitreous hemorrhage. There was a striking difference in intraocular circulation between right and left eye,suggesting the possible involvement of extraocular lesions. Magnetic resonance angiography showed bilateral stenosis of internal carotid arteries. Rubeosis iridis disappeared spontaneously 9 days after surgical treatment by stenting. Additional vitreous surgery resulted in improved left visual acuity to 0.3. This case illustrates that impaired extraocular circulation may be involved in the presence of differences in ischemic lesions between both eyes.