Multifocal electroretinogram and ICG angiogram in acute zonal occult outer retinopathy

Purpose. To study visual field abnormality in acute zonal occult outer retinopathy(AZOOR) (Gass, 1993). Methods. Six patients with the diagnosis of multiple evanescent white dots syndrome, acute idiopathic blind spot enlargement or multifocal choroiditis were involved in this study. Multifocal electroretinogram(ERG) (Sutter, 1992), full field ERG(ISCEV protocol), fluorescein and ICG angiograms were tested. Results. All patients with AZOOR showed marked reduction in amplitude of focal ERGs in the area of scotoma, but little delay in peak time. Full field ERG showed interaocular asymmetry (Jacobson et al, 1995) in 5 cases. Fluorescein and ICG angiogram showed no evidence of circulatory disturbance in the area of scotoma. Conclusion. Visual field defects in AZOOR were caused by localized retinal dysfunction which could be demonstrated by multifocal ERG. In some cases with AZOOR, multifocal ERG may be essential to the diagnosis. There was no evidence that zonal retinal dysfunction was produced by circulatory disturbance.