急性網膜壊死治療後のアシクロビル予防量投与中に僚眼に発症した1例

A case of acute retinal necrosis during acyclovir prophylaxis

要約　目的：片眼急性網膜壊死治療後のアシクロビル予防量投与中に僚眼に急性網膜壊死を発症した症例を経験したので報告する。

症例：66歳，女性。2019年7月に急性骨髄性白血病に対して造血幹細胞移植を施行された。アシクロビル200mg/日内服中に左視力低下を主訴に和歌山県立医科大学附属病院眼科を受診した。初診時視力は右（0.8），左（0.09）。右眼は異常なく，左眼に前房内炎症細胞，網膜周辺の白色病変，裂孔原性網膜剝離を認め同日入院した。入院日から抗サイトメガロウイルス薬，翌日からアシクロビルの点滴治療を施行し，入院6日目に網膜剝離に対して手術を行った。前房水と硝子体液から水痘・帯状疱疹ウイルスが検出され，急性網膜壊死と診断した。アシクロビル点滴（5mg/kg×3回/日）2週間，バラシクロビル内服3,000mg/日2週間の全身投与後，病勢が鎮静化したと判断し，アシクロビル200mg/日を継続したが，約1か月後に右眼に白色病変が出現，その後裂孔原性網膜剝離が発症し左眼と同様の治療を行った。バラシクロビル3,000mg/日内服を3週間継続するも副作用のためアメナメビルに変更したが，血球減少のため再度バラシクロビル1,000mg/日に変更したところ症状は改善，以降再発はない。

結論：造血幹細胞移植の患者を対象とした研究で，アシクロビル200mg/日の有用性が報告されているが，免疫不全状態にある患者の急性網膜壊死の発症および僚眼発症に対する予防はアシクロビル200mg/日では不十分の可能性がある。

Abstract　Objective：We report a case of acute retinal necrosis in the companion eye during administration of acyclovir preventive dose after treatment for acute retinal necrosis in one eye.

Case：66 year old female. Hematopoietic stem cell transplantation was performed for acute myeloid leukemia in July 2019. The patient visited our department with a chief complaint of decreased left visual acuity while taking acyclovir 200 mg/day. Visual acuity at the first visit was normal in the right eye（0.8）, left eye（0.09）, and right eye, and anterior chamber inflammatory cells were found in the left eye, white lesions around the retina, and rhegmatogenous retinal detachment were observed, and the patient was hospitalized on the same day. Anti-cytomegalovirus drug was administered from the day of admission, and acyclovir was infused from the next day, and surgery was performed for retinal detachment on the 6th day of admission. Varicella-zoster virus was detected in the anterior chamber water and vitreous humor, and acute retinal necrosis was diagnosed. After systemic administration of acyclovir infusion（5 mg/kg×3 times a day）for 2 weeks and valacyclovir oral administration 3,000 mg/day for 2 weeks, it was judged that the disease had subsided, and acyclovir 200 mg/day was continued, but right after about 1 month. A white lesion appeared in the eye, and then rhegmatogenous retinal detachment developed, and the same treatment as for the left eye was performed. Valaciclovir 3,000 mg/day was changed to amenamevir due to side effects even after 3 weeks of continuous administration, but due to cytopenia, valacyclovir was changed to 1,000 mg/day again, and no recurrence has been observed since then.

Conclusion：A study of patients with hematopoietic stem cell transplantation reported the usefulness of acyclovir 200 mg/day, but acyclovir 200 mg/day is effective in preventing the development of acute retinal necrosis and concomitant eye in immunocompromised patients. It may be inadequate.