Figure 3. ERG recording under different conditions

ERGs were recorded under standard conditions of 30 min dark-adaptation for affected family members number 11 and 13, and two normal controls (upper two rows) and after 4 h of dark adaptation for three affected members (number 11, 13, 15) and two carriers (number 9, 14). A non-recordable ERG b-wave becoming normal after 4 h of dark adaptation was observed in a patient (number 11) but not in other two affected subjects (number 13, 15). Cone 30 Hz flicker responses had essentially normal amplitudes for all three patients.