Wave 3 in a scotopic ERG corresponds to which wave label?

Wave 3 in a scotopic ERG corresponds to which wave label?

• A. A-wave in photopic ERG
• B. B-wave in photopic ERG
• C. C-wave in scotopic ERG
• D. A-wave in scotopic ERG

Answer: (C)

In a scotopic ERG, dark-adapted conditions highlight the sequence of retinal responses from rods. The first negative deflection is the A-wave, reflecting photoreceptor activity (mostly rods). The following positive wave is the B-wave, arising mainly from ON-bipolar cells and Müller cells. After these comes a slower, broader positive deflection known as the C-wave, which is linked to the retinal pigment epithelium’s response to changes in the outer retina after the flash. So, the third wave seen in a scotopic ERG is the C-wave, not the A- or B-wave, and it represents the RPE-related response rather than photoreceptors or bipolar cells. Photopic ERGs involve cone-driven responses and follow a different labeling for those waves.

In a scotopic ERG, dark-adapted conditions highlight the sequence of retinal responses from rods. The first negative deflection is the A-wave, reflecting photoreceptor activity (mostly rods). The following positive wave is the B-wave, arising mainly from ON-bipolar cells and Müller cells. After these comes a slower, broader positive deflection known as the C-wave, which is linked to the retinal pigment epithelium’s response to changes in the outer retina after the flash.

So, the third wave seen in a scotopic ERG is the C-wave, not the A- or B-wave, and it represents the RPE-related response rather than photoreceptors or bipolar cells. Photopic ERGs involve cone-driven responses and follow a different labeling for those waves.