転移性眼内炎の罹患から1か月後に僚眼の壊死性ヘルペス網膜炎を発症した1例

A case of necrotizing herpetic retinitis of the fellow eye one month after metastatic endophthalmitis

要約　目的：転移性眼内炎に罹患した1か月後に僚眼の壊死性ヘルペス網膜炎を発症した1例を経験したので報告する。

症例：75歳，男性。膀胱癌に対する化学療法中に薬剤性肝炎を発症し，プレドニゾロン40mg/日を内服中であった。後腹膜膿瘍で入院加療中，左眼の視力低下を認め，眼科に紹介となった。左眼に前房蓄膿と硝子体混濁を認め，後腹膜膿瘍よりKlebsiella pneumoniaeが検出されたことから転移性眼内炎を疑い，硝子体切除術を施行し，硝子体培養から同種の菌が検出された。1か月後，右眼の視力低下を訴え，右眼周辺部に顆粒状の黄白色病変を認めた。数日で病変は黄斑部と視神経乳頭部を除く全網膜に拡大した。発症の1か月前に帯状疱疹の治療を受けていたことから壊死性ヘルペス網膜炎を疑いアシクロビルとベタメタゾン，アシクロビル耐性の可能性を考慮しガンシクロビルの点滴と，ホスカルネットの硝子体内投与を開始した。前房水PCR検査の結果，水痘帯状疱疹ウイルスが検出された。治療開始後，病変は徐々に消退したが病変が出現した網膜は全層にわたり壊死した。最終視力は右（0.1），左手動弁/30cmとなった。

結論：免疫能が低下している患者では，異なる重篤な感染性ぶどう膜炎を併発しうるため，常に複数の鑑別診断を念頭に置くべきである。

Abstract　Purpose：To report a case of necrotizing herpetic retinitis in the fellow eye of a patient who had been diagnosed with metastatic endophthalmitis a month before.

Case：The patient was a 75-year-old man who developed drug-induced hepatitis during chemotherapy for bladder cancer and was on prednisolone 40 mg/day. While hospitalized for a retroperitoneal abscess, he developed decreased visual acuity in the left eye and was referred to an ophthalmologist who diagnosed an anterior chamber abscess and vitreous opacity in the left eye. Klebsiella pneumoniae was detected in the retroperitoneal abscess, suggestive of metastatic endophthalmitis. We performed a vitrectomy, collected the vitreous humor, and detected the same species in culture. One month later, he complained of decreased vision in the right eye and a granulated yellowish-white lesion was observed in the periphery of the retina. Within a few days, the lesion extended to the entire retina, except the macula and optic nerve papilla. Necrotizing herpetic retinitis was suspected because he had been treated for herpes zoster a month before. He had been treated with intravenous acyclovir and betamethasone at that time, taking into consideration possible acyclovir resistance, intravenous ganciclovir and intravitreal injections of foscarnet were started. PCR testing of the aqueous humor showed presence of herpes zoster virus. The lesions gradually disappeared on starting treatment, but the retinal layers containing the lesions became necrotic. Final visual acuity was 0.1 in the right eye and hand motion at 30 cm in the left eye.

Conclusion：Multiple differential diagnoses should be considered in immunocompromised patients, because different etiologies for severe infectious uveitis can occur simultaneously.