To review the efficacy of the pattern electroretinogram
) in early diagnosis
Stimulation parameters of check size and temporal frequency are considered. Analyses of various peaks (P50, N95, the N95/P50) and Fourier steady-state are considered. The relation to visual field defects is explored.
is markedly alterated in glaucoma
. It shows amplitude reductions in (still) normal areas of the visual field. Optical imaging on the retina needs to be optimal. Higher temporal frequency (>10 reversals/s) improves the sensitivity to detect glaucoma
compared with transient stimulation. The ratio between the amplitudes to 0.8° checks and to 16° checks, “PERG
ratio,” exploits a check size-specific reduction in early glaucoma
and reduces variability. Longitudinal studies suggest that the PERG
can indicate incipient glaucoma
damage before evidence from the visual field.
is a demanding electrophysiological technique that can serve as a sensitive biomarker for retinal ganglion cell function. With appropriate paradigms, PERG
assists in identifying those patients with elevated interocular pressure in whom glaucoma
damage is incipient before visual field changes occur.