Figure 4
From: Photopic negative response recorded with RETeval system in eyes with optic nerve disorders
Illustration of the methods to measure various components of the ERG waveform. Arrows represent the amplitude of each parameter. The a-wave amplitude was measured from the pre-stimulus baseline to the first negative trough (a). The b-wave amplitude was measured from the a-wave trough to the positive peak (b-a). The P72 amplitude was measured at 72 ms after the stimulus onset, and the amplitude of Pmin was measured at the negative trough following the b-wave. The calculation of Pratio and Wratio was done as shown in the figure.
