汎網膜光凝固眼の広角赤外螢光眼底造影所見

Wide-angle indocyanine green angiography in diabetic retinopathy after panretinal photocoagulation

　走査レーザー検眼鏡（SLO）を用いた赤外螢光眼底造影により，汎網膜光凝固後の脈絡膜循環を観察した。筆者らが開発した広角造影法を併用して，正常眼10眼と汎網膜光凝固後の増殖糖尿病網膜症19眼を検索した。この方法により，渦静脈を越える周辺まで脈絡膜血管を観察できた。汎網膜光凝固後には，全例で光凝固部全体の螢光輝度が低下していた。個々の光凝固斑ではベール状螢光が欠如し，脈絡毛細管板の閉塞と考えられた。光凝固斑を横切る脈絡膜血管が観察可能であり，光凝固領域全体の脈絡膜血管は光凝固前に比べ狭細化していた。治療量の汎網膜光凝固後では，脈絡毛細管板の閉塞と脈絡膜螢光輝度の低下があり，これは脈絡膜血液量の減少と判断され，さらに，脈絡膜血管の狭細化が起こっていた。

We evaluated 19 eyes with proliferative diabetic retinopathy before and after panretinal photocoagulation. We used a panoramic technique using indocyanine green angiography attached with a hand-held superfield noncontact lens. This technique allowed observation of the fundus beyond the site of vortex veins. The findings were compared with those in 10 healthy eyes. Each photocoagulated spot was characterized by absence of diffuse background fluorescence suggesting obliteration of choriocapillaris. Also, the whole retinal area treated by photocoagulation showed significantly decreased fluorescence. Major choroidal vessels running through the coagulated spots showed marked narrowing as compared with pretreatment state. The findings seemed to suggest that panretinal photocoagulation induces decreased choroidal vascular flow associated with occlusion of choriocapillaris and attenuation of choroidal vessels.