難治性多発性骨髄腫の寛解と増悪に伴う眼底病変の変化を1年観察できた1例

Fundus findings followed up for one year in a case with fluctuations of multiple myeloma

要約　目的：化学療法が1年間行われた難治性多発性骨髄腫の1症例での眼底所見の経過報告。

症例：68歳男性が未治療の多発性骨髄腫IgA-λ型として，内科から紹介され受診した。高蛋白血症と高度の貧血があった。

所見と経過：矯正視力は右0.6，左0.7で，両眼に網膜中心静脈閉塞症様の所見があった。化学療法とデキサメタゾンの全身投与が開始され，2か月後に血清IgAが低下し，眼底所見が改善した。その後，内科治療への反応が低下し，初診から13か月後に血清λ型の顕著な増加，高度の貧血，血小板の減少があり，網膜出血が増加し，左眼には網膜前出血が生じた。

結論：本症例は過粘稠度症候群により網膜中心静脈閉塞症様の変化が生じ，内科的加療により眼底所見がいったん改善した。経過中に貧血網膜症が生じ，顕著な血小板減少が加わったことで網膜前出血が生じたと考えられる。

Abstract　Purpose：To report a case of multiple myeloma with changes in fundus findings followed up for one year.

Case：A 68-year-old male was referred to us for type IgA-λ multiple myeloma before start of treatment. He had hyperproteinemia and marked anemia.

Findings and Clinical Course：Corrected visual acuity was 0.6 right and 0.7 left. Both eyes showed mild findings of central retinal vein occlusion（CRVO）. He then started receiving chemotherapy and systemic dexamethasone. He showed decreased serum IgA level associated with improved fundus findings 2 months later. He then showed resistance to treatment, and 13 months later, showed marked increase in serumλ fraction, severe anemia and decrease in platelets. Both eyes showed increase in retinal hemorrhage. The left eye showed preretinal hemorrhage.

Conclusion：The present case showed findings simulating CRVO as manifestation of hyperviscosity syndrome. Fundus findings temporarily improved following systemic treatment. Anemia with decrease in platelets appeared to have led to exacerbation of fundus lesions.