Figure 4. Results of focal macular electroretinograms (ERGs) and multifocal ERGs. Focal macular ERGs and oscillatory potentials recorded from a normal subject and this case are shown (top). The amplitude of the a-wave of this case was severely reduced, and the plateau region was significantly elevated (arrows). The topographic map and the local responses of multifocal ERGs recorded from the normal subject and this case are shown (bottom). The amplitudes in the foveal area were severely reduced in this case.