10年後に僚眼に発症しウイルス定量を行った急性網膜壊死の1例

A case of acute retinal necrosis due to the varicella-zoster virus that recurred in the fellow eye 10 years later and quantification of the virus

要約　目的：片眼の水痘帯状疱疹ウイルス（VZV）による急性網膜壊死（ARN）の発症10年後に僚眼にも同ウイルスによるARNが発症し，初発眼および10年後の再発眼ともPCR定量を行った症例の報告。

症例：66歳，男性。前医にて10年前に右眼にVZV（前房水にて6.8×10⁶copies/ml）によるARNを罹患し，網膜剝離を発症した。治療として，抗ウイルス療法や硝子体手術により加療されていた。左眼のARNの疑いで当院を受診した。当院受診時の矯正視力は右（0.1），左（0.5）であり，左眼の角膜後面沈着物，眼底上方の黄白色滲出斑を認めた。臨床所見と反対眼の経過から，僚眼にARNが発症したと判断した。即日入院とし，アシクロビルの点滴とステロイドの全身投与を行った。当院受診時に採取した前房水からは6.8×10⁴copies/mlのVZVが検出され，10年前に測定した初発眼に比べて1/100であった。治療後，左眼の硝子体混濁は増悪なく，最終視力は左（0.6）であった。現時点でも網膜剝離の発症はない。

結論：片眼のARN発症から10年後に僚眼に再発することがあり，右眼に比べてウイルス量が少ない左眼は予後が良好であった。

Abstract　Purpose：To report a case of acute retinal necrosis（ARN）that involved the fellow eye caused by the varicella-zoster virus and perform polymerase chain reaction quantification for both the first eye and the recurrent eye 10 years interval.

Case：The patient was a 66 years old man who had acute retinal necrosis due to the varicella-zoster virus（6.8×10⁶ copies/ml in the aqueous humor）10 years ago in the right eye, which developed retinal detachment. For treatment, the patient had been given antiviral therapy and vitrectomy. He was admitted to our hospital for suspected ARN of the left eye. The corrected visual acuity at the time of visit to our hospital was right（0.1）and left（0.5）, and keratic precipitates of the left eye and yellowish white exudate spots on the upper fundus were observed. Based on the clinical findings and the course of the opposite eye, it was judged that ARN had developed in the fellow eye. The patient was hospitalized on the same day and was given systemic administration of acyclovir infusion and steroids. Varicella-zoster virus（6.8×10⁴ copies/ml）was detected in the aqueous humor collected at our hospital, which was 1/100 of the initial copy number measured 10 years ago. After treatment, the vitreous opacity of the left eye improved and the final visual acuity was left（0.6）. Currently, there is no retinal detachment.

Conclusions：ARN may recur in the fellow eye 10 years later. Moreover, the left eye, which had a lower viral load than the right eye, had a better prognosis.