A 12-YEAR-OLD Caucasian female was seen initially with a 4-week history of a sudden localized visual-field loss in the left eye. The ocular symptoms followed a viral infection associated with high fevers the previous week. The scotoma was unchanged in shape or density on subjective assessment and had no associated photopsias since onset. On examination, her visual acuity was 20/20 OU. Results of Goldmann perimetry showed a dense, nasal perifoveal scotoma that was steeply marginated (Figure 1). There was a definable normal area between the scotoma and the optic nerve shadow. The fellow eye was normal. Fundus examination showed a slightly dark to reddish brown deep macular lesion (Figure 2A). Fluorescein angiography findings were normal (Figure 2B), and no vitreous cells were noted. Multifocal electroretinographic (mf ERG) examination was performed under photopic conditions and the first-order responses are presented. The waveforms of the right eye exhibited normal amplitude and latency (Figure 3A). There was a localized area of severe decreased retinal response in the left eye (Figure 3B). This area corresponded well to the scotoma noted on Goldmann perimetry (Figure 1). The latency of the affected waveforms was normal (not shown). The 3-dimentional response-density graph clearly demonstrated the relative focal loss of response in the left eye (Figure 4B) and a moderate, generalized depression of response density when compared with the unaffected right eye (Figure 4A). There was a 40% depression of the overall response density of the left eye compared with the right (10 vs 17 n V/degrees2).