細菌性眼内炎を疑ったリファブチン関連ぶどう膜炎の1例

A case of rifabutin-associated uveitis suspected as bacterial endophthalmitis

要約　症例：56歳。女性。右足関節Mycobacterium Kansasii骨髄炎に対するリファブチンおよびクラリスロマイシン内服開始2か月後に突然左視力が低下し，左眼に前房蓄膿を伴うぶどう膜炎を発症した。

所見：初診時，左視力は15cm指数弁となり，高度の硝子体混濁のため眼底は透見不能であった。患者が全身性エリテマトーデスによる腎症で透析中と免疫低下状態であったことから，細菌性眼内炎を疑った。初診当日（発症3日目）に眼内レンズ抜去，前房洗浄，硝子体手術を施行し，抗菌薬の局所および全身治療を開始した。しかし，術後2日目，右眼にも前房蓄膿を伴うぶどう膜炎を発症した。左硝子体の細菌培養は陰性であり，また抗菌薬の全身投与中の発症であったため，感染症ではなくリファブチンによるぶどう膜炎を疑った。リファブチン内服を中止し，ステロイド点眼および複数回の後部テノン囊下注射を施行した，発症25日目には両眼とも炎症は消失し，左視力は1.0に回復した。

結論：筆者らは前房蓄膿を呈したリファブチン関連ぶどう膜炎を経験した。リファブチンの副作用の1つにぶどう膜炎が知られており，その内服中に前房蓄膿を伴うぶどう膜炎が発症した場合，薬剤性ぶどう膜炎の可能性も念頭に置くことが大切である。

Abstract　Case：The patient was a 56-year-old woman. Two months after initiating rifabutin and clarithromycin for M. Kansasii osteomyelitis of the right ankle joint, her left visual acuity suddenly decreased, and uveitis with hypopyon developed in the left eye.

Observation：On her first visit to our hospital, the visual acuity in her left eye was 15 cm/n.d, and the fundus was not transparent due to severe vitreous opacity. The patient was immunocompromised dialysis for systemic lupus erythematosus nephropathy；therefore bacterial endophthalmitis was suspected. On the same day（the third day of the onset）, she underwent intraocular lens removal, anterior chamber lavage, and vitrectomy. Simultaneously, local and systemic treatment with antibacterial agents was initiated. However, the patient developed uveitis with hypopyon in the right eye on second postoperative day. Since bacterial culture of the vitreous in her left eye was negative and the uveitis onset in her right eye occurred during the systemic administration of antimicrobial agents, rifabutin-induced uveitis was suspected rather than infection. After rifabutin administration was discontinued, steroid eye drops and multiple sub-Tenon triamcinolone acetonide injections were administered. Ocular inflammation in both eyes had subsided and the left visual acuity was recovered to 1.0 on the 25th day of the onset.

Conclusion：We have reported a case of rifabutin-associated uveitis with hypopyon. As uveitis is one of the known side effects of rifabutin, it is essential to consider the possibility of drug-induced uveitis when uveitis with hypopyon develops under administration with rifabutin.