糖尿病性網膜症における網膜内細小血管異常の経時的変化

Intraretinal microvascular abnormalities (IRMA) in diabetic retinopathy

　当科糖尿病外来通院中の患者のうち，2回以上の螢光眼底検査でintraretinal microvas-cular abnormalities （IRMA）を認めた34例47眼について，IRMAの経時的変化を観察し，生命表法を用いて分析した．

　IRMAには網膜毛細血管網の形に似たものと異常な走行を示す血管の2種類がみられた．今回はこの両者をIRMAとしてあわせて検討した．IRMAは生命表法によると経過観察とともに徐々に増大し，半年で約1割の部位で，1年で約2割の部位で，2年で約3割の部位でIRMAの増大がみられた．この速さに糖尿病性網膜症の病期や光凝固の有無が関与していることが示唆された．

We observed intraretinal microvascular abnor-malities (IRMA) of diabetic retinopathy in 47 eyes (34 cases) under fluorescein angiography, in order to investigate how IRMA developed by a method of life-table analysis (Kaplan-Meier's method). IRMA in this study were defined as arterio-venous collateralization adjacent to retinal capillarynonperfused areas. There were two types of IRMA. One type was supposed to have originated from recanalized capillaries, and the other was intra-retinal neovascularization. After a 6 month follow -up, IRMA developed in 9%, in 23% after 1 year, and in 29% after 2 years. The stage of diabetic retinopathy and photocoagulation affected the rapidity of development of IRMA.

Rinsho Ganka (Jpn J Chn Ophthalmol) 42(2) : 118-120, 1988