The pattern electroretinogram: technical aspects and clinical significance.

The pattern electroretinogram (PERG), thought to be generated in retinal ganglion cells, is a recent addition to the neurophysiologic assessment of retinal function. Factors that affect the PERG include type of pattern-reversal stimulus, spatial frequency of the pattern, luminance and contrast of the pattern, method of waveform processing, type of electrode employed, electrode montage, background illumination, position of stimulus on the retina, temporal frequency of pattern reversal, refractive error, and patient age. Clinical entities reported to affect the PERG include glaucoma and ocular hypertension, optic neuritis, other optic neuropathies, maculopathies, and amblyopia. Technical aspects and clinical significance of the PERG are reviewed.