原田病様眼底を示した慢性骨髄性白血病の1例

A case of chronic myelocytic leukemia manifesting fundus lesions simulating Harada disease

　57歳男性が5日前からの両眼の霧視で受診した。7年前に慢性骨髄性白血病と診断され加療中であった。裸眼視力は右0.2，左0.15，遠視を矯正して右1.2，左1.0であった。前眼部に炎症所見はなく，両眼の眼底後極部に漿液性網膜剥離があった。フルオレセイン蛍光造影で，早期には乳頭と黄斑部の周囲に多数の点状蛍光点があり，後期にはこれが拡大して網膜下に蛍光貯留が生じた。内科でプレドニゾロンと抗癌剤の投与を行った。初診から1週後に網膜剥離は軽減し，視力が改善した。このときのICG蛍光造影で，早期には脈絡膜への充盈遅延があり，中期には脈絡膜血管が不明瞭で全体的に低蛍光であった。眼底と蛍光造影所見は原田病のそれに酷似したが，本例では，脈絡膜に白血病細胞が浸潤し，脈絡膜循環障害の結果として網膜色素上皮細胞が障害され，漿液性または浸潤性網膜剥離が生じたと解釈される。ICG蛍光造影で，脈絡膜循環障害が眼底の広範囲にあることが確認できた。

A 57-year-old male presented with bilateral visual blurring since 5 days before. He had been under treatment for chronic myelocytic leukemia for 7 years. His visual acuity was 0.2 right and 0.15 left without correction and 1.2 right and 1.0 left after corrected for hyperopia. No inflammatory signs were present in the anterior segment. Serous retinal detachment was present in the posterior fundus area in both eyes. Fluorescein angiography showed numerous fluorescent dots in the detached area during the early phase. The dots enlarged later to result in dye pooling beneath the detached retina. After one week of systemic prednisolone and anticancer agents, the retinal detachment resolved with improved visual acuity. Indocyanine green (ICG) angiography showed delayed dye filling in the choroid during the early phase. The choroidal vessels were indistinct associated with diffuse hypofluorescence during the middle phase. This case illustrates that chronic leukemia may induce fundus lesions simulating Harada disease. It appeared that serous retinal detachment was caused by impaired retinal pigment epithelium secondary to choroidal circulatory disturbances due to leukemic cell infiltration. ICG angiography was instrumental in detecting the presence and extent of disturbed choroidal circulation.