網膜振盪部に限局的に生じた網膜全層浮腫に一致して視野障害を呈した1例

A case of visual field defect consistent with full-thickness retinal edema in a retinal concussion area

要約　目的：網膜振盪は鈍的外傷後に一過性にみられる網膜混濁で，多くは視機能障害を残すことなく軽快する。今回，網膜振盪部に限局性の網膜全層浮腫を生じ，この部位に一致した視野障害を残した1例を報告する。

症例：18歳，男性。2015年にソフトボールによる右眼打撲後，翌日に当科初診。

所見：右視力（1.5），右眼圧14mmHg，右眼は毛様充血，前房出血，隅角後退を認めた。眼底は耳上側後極部から周辺部に網膜混濁病巣がみられ，斑状出血，軽度硝子体出血を認めた。光干渉断層計（OCT）では網膜混濁部にてellipsoid zoneの不整が描出されたが，網膜内層は保たれていた。網膜静脈第一分枝部の耳側に，限局性の漿液性網膜剝離，網膜外層・内層全体の高反射（全層浮腫）および，硝子体細胞，後部硝子体剝離を認めた。眼底自発蛍光では同部位の耳側に弧状の線状低蛍光がみられた。視野検査では全層浮腫部に一致して比較暗点を認めた。フルオレセイン蛍光眼底造影では網膜混濁部の蛍光漏出はみられなかった。2週間後には網膜混濁は消失，OCTで全層浮腫部に一致して網膜の菲薄化を認め，比較暗点は2年後も残存した。

結論：網膜振盪部に限局性の網膜全層浮腫を生じ，同部位に一致して視野障害を呈した1例を経験した。鈍的眼球打撲後に視野障害を生じる原因の1つとして網膜全層浮腫があり，multimodal imagingは病状の把握に有用であった。

Abstract　Purpose：Retinal concussion（commotio retinae）is transient retinal opacity after blunt trauma, and most cases resolve without residual visual impairment. Here, we report a case of focal full-thickness retinal edema in a retinal concussion area with congruent visual field defects.

Case：The patient was an18-year-old man. In 2015, his right eye was bruised by softball. He first visited our department the following day.

Findings：The best-corrected visual acuity was 1.5 in the right eye. Intraocular pressure was 14 mmHg in the right eye. Ciliary injection, hyphema, and angle recession were observed. In the fundus, retinal opacification was observed from the upper-temporal side of the posterior pole to the periphery, with retinal hemorrhage and mild vitreous hemorrhage. Optical coherence tomography（OCT）showed irregularities in the ellipsoid zone in the opacified part of the retina, but the inner retinal layer was preserved. Focal serous retinal detachment, hyperreflectivity of the outer and inner layers of the retina（full-thickness edema）, vitreous cells, and posterior vitreous detachment were observed on the temporal side of the first branch of the retinal vein. In fundus autofluorescence, arc-shaped hypofluorescence was observed on the temporal side of the same site. A visual field examination revealed a comparative scotoma corresponding to the full-thickness edematous area. Fluorescein angiography showed no fluorescence leakage in the area of retinal opacity. Two weeks later, the retinal opacity disappeared, and OCT revealed retinal thinning consistent with full-thickness edema, and the comparative scotoma remained 2 years later.

Conclusions：We experienced a case of focal full-thickness retinal edema in a retinal concussion area with congruent visual field defects after blunt ocular trauma. One of the causes of visual field defects in retinal concussion is full-thickness retinal edema. Multimodal imaging was useful in the diagnosis and understanding pathological status of retinal concussion.