慢性骨髄性白血病の1症例における2階調化法による脈絡膜構造変化の検討

Choroidal structure changes in chronic myeloid leukemia by binarization method

要約　目的：慢性骨髄性白血病（CML）の1症例において，化学療法前後の脈絡膜構造の変化を脈絡膜EDI-OCT画像の2階調化法により検討を行った。

症例：30歳，男性。

所見：右眼視力低下と近医による眼底出血の指摘により当科を紹介され初診となった。網膜所見と白血球数の異常高値（501,310/μl），FISH検査結果からCMLの診断に至った。治療1か月後で脈絡膜厚と血管腔・間質面積は急激に減少したが，管腔脈絡膜面積比（L/C）は経過を通して約70％程度で推移し変動を示さなかった。

結論：本CML症例の経時的EDI-OCTの比較検討では，急性期に脈絡膜の管腔・間質面積はどちらも拡大していたが，L/C比には変化を認めず，治療1か月後には管腔・間質面積は急激に低下し，その減衰曲線は白血球数減少曲線に一致していた。

Abstract　Purpose：To investigate the choroidal structure before and after chemotherapy in a patient with chronic myeloid leukemia（CML）using a binarization method of EDI-OCT.

Case report：A 30-year-old man had blurred vision in the right eye and was referred to the Department of Ophthalmology, Teine Keijinkai Hospital, for further examinations of fundus hemorrhages in both eyes. The best-corrected visual acuity at the first visit was 0.2 right eye and 1.2 left eye. Based on the fundus examination findings, a high leukocyte count of 501,310/μl, and positive detection of BCR-ABL translocation on FISH testing, he was diagnosed with CML and immediately underwent chemotherapy. OCT analysis conducted one month after the treatment revealed that the thickness of the choroidal, luminal, and stromal areas rapidly decreased, whereas the luminal-choroidal area（L/C）ratio showed a flat line during the follow-up period.

Conclusion：In the acute phase of CML in the present patient, both the luminal and stromal areas, but not the L/C ratio in the choroid, were enlarged. After initiation of chemotherapy, these values improved, whereas the leucocyte count decreased.