Clinical study of the pattern electroretinogram in patients with optic nerve damage.
We have recorded both pattern and flash electroretinograms (ERG) in two patients with unilateral optic nerve damage due to optic canal fracture over one year. The pattern ERG from the affected eye was reduced in amplitude by approximately 40% in one patient, 60% in the other, compared with that from their other, normal eyes, while the flash ERG was normal in all eyes. Reduced pattern ERG responses may depend on retrograde degeneration following damage to the optic nerve. The pattern ERG, however, was not totally lost in the eyes with marked optic atrophy. There is a possibility that the pattern ERG contains both contrast and luminance components in various proportions.