片眼の錐体機能異常を呈したacute zonal occult outer retinopathy様症例

A unilateral case suspected of acute zonal occult outer retinopathy with cone dysfunction

要約　目的：求心性視野狭窄と強い錐体機能障害がある片眼性のacute zonal occult outer retinopathy（AZOOR）が疑われる症例の報告。症例：12歳男子が2年前からの左眼視力低下，視野異常，光視症で受診した。所見：矯正視力は右1.2，左0.8で，両眼とも前眼部から眼底まで異常がなかった。フルオレセイン蛍光眼底造影は正常で，限界フリッカ値も正常所見を呈した。左眼の相対的瞳孔求心路障害（RAPD）は陽性で，Humphrey視野検査で左眼に求心性狭窄があった。網膜電図（ERG）では左眼の錐体反応，多局所ERGの応答，30Hzフリッカ応答が著しく減弱していた。結論：本症例では著しい錐体機能障害が左眼にあることが電気生理学的検査で確認され，臨床所見からAZOORの1型と推定される。

Abstract.　Purpose：To report a case of cone dysfunction suspected of unilateral acute zonal occult outer retinopathy（AZOOR）. Case：A 12-year-old boy presented with impaired visual acuity,visual field defect and photopsia in the left eye of 2 years' duration. Findings：His corrected visual acuity was 1.2 right and 0.8 left. Both eyes showed normal findings in the anterior segment,optic media and the fundus. Fluorescein fundus angiography and critical flicker fusion frequency were normal. The left eye showed positive relative afferent pupillary defect（RAPD）and visual field constriction by Humphrey perimetry. Electroretinogram showed remarkable decrease in cone function and response to 30-Hz response. Multifocal ERG was also reduced in the left eye. Conclusion：Remarkably impaired cone dysfunction was present in the left eye by electrophysiological examinations. The findings suggest that the present case may belong to a type of AZOOR.