Figure 3.

Graphical representation of full-field electroretinography (ERG) findings and examples of recordings. (A) ISCEV-standard full-field ERG amplitudes are plotted as a percentage of the lower limit of normal obtained in a control group for right (RE) and left (LE) eyes. The findings were consistent with a severe cone-rod dystrophy (Patients P1, P2A, P2B, P3, and P4) or severe photoreceptor dystrophy (P16; undetectable ERGs). (B) Examples of ISCEV-standard full-field ERG traces recorded from Patients P1, P2, P3, and P4 and a representative unaffected control subject (N) for comparison. Dark-adapted (DA) ERGs are shown for flash strengths of 0.01 and 10.0 cd.s/m² (DA 0.01; DA 10.0). Light-adapted (LA) ERGs are shown for a flash strength of 3.0 cd.s/m² (LA 3.0; 30 Hz and 2 Hz). Recordings are shown from 1 eye with traces superimposed to demonstrate reproducibility. Note the higher scaling factor used to illustrate low-amplitude DA ERGs compared with the control. Broken lines replace blink artefacts that occur after the ERG b-waves. Pattern ERGs were not recordable owing to the effects of marked nystagmus in all patients.