草刈り機による射創性脈絡網膜症と眼窩内金属異物の1例

A case of lawn mower injury with chorioretinitis sclopetaria and intraorbital metallic foreign body

要約　目的：電動草刈り機による射創性脈絡網膜症と眼窩内金属異物の1例を報告する。

症例：80歳，女性。家族が電動草刈り機の作業中，右眼を受傷して受診した。初診時，右眼の視力は指数弁，眼圧は12mmHgで，右上眼瞼に刺入創がみられた。眼底検査では，右眼の硝子体出血，網膜前出血，網膜震盪症，網脈絡膜損傷を認めた。頭部CT検査にて右眼窩内に金属異物を認めた。受傷翌日に脳神経外科にて眼窩内異物摘出術を施行した。経過観察中に生じた右眼の網膜剝離に対し，白内障手術と硝子体手術を施行し，術中に網脈絡膜破裂と白色の結合組織増殖を認めた。増殖組織による右眼の網膜再剝離に対して硝子体手術を再施行した。最終受診時，右眼の視力は0.15で，網膜は復位していた。

結論：金属異物が上眼瞼を経由し，眼球を穿孔することなく，眼窩内に刺入して生じた射創性脈絡網膜症と考えられた。本症に続発する網膜剝離や増殖硝子体網膜症に注意が必要である。

Abstract　Purpose：To report a case who showed metallic foreign body in the orbit and chorioretinitis sclopetaria following injury by an electric lawn mower.

Case：An 80-year-old woman received injury in the right eye while her family member was working with an electric lawn mower.

Findings and Clinical Course：Visual acuity in the right eye was counting fingers with intraocular pressure of 12 mmHg. The right upper eyelid showed a punctured wound. The right eye showed vitreous and preretinal hemorrhage, commotio retinae and chorioretinal damage. Computed tomography showed a metallic foreign body in the right orbit, which was removed by surgery. The right eye developed retinal detachment 5 weeks later. Chorioretinal rupture with fibrous proliferation was found during vitreous surgery. Retinal detachment recurred 9 weeks later and was treated by another surgery. Final visual acuity remains at 0.15.

Conclusion：The metallic foreign body seems to have entered through the upper eyelid. While it did not penetrate the eyeglobe, it caused chorioretinitis sclopetaria.