Figure 3. Full-field electroretinogram (ERG) characteristics in case IV 1 (A), case II 1 (B), and a control subject (C) are presented. Dim light scotopic response (dark adapted [DA] ERG to 0.01 cd-seconds per square meter–DA 0.01 ERG) showed severe b-wave reduction in case IV 1 (3A) and was at the lower limit of normal in case II 1 (B). Both cases showed electronegative configuration to combined rod-cone response (DA ERG to 2.29 cd-seconds per square meter – DA 2.29 ERG; A and B), and case IV 1 showed additional a-wave involvement. Single flash photopic response (light adapted (LA) ERG to 2.29 cd-seconds per square meter–LA 2.29 ERG) showed severe reduction and delay of the a- and b-waves with reduced b/a ratio in both subjects (A and B). The 30 Hz flicker response (LA 30 Hz flicker) showed severely reduced and delayed b-waves in both cases (A and B). Please note that the scale on the y-axis is different for the cases and the control.