Abnormal pattern electroretinogram in Alzheimer's disease: Evidence for retinal ganglion cell degeneration?

We recorded pattern‐reversal electroretinograms, flash electroretinograms, pattern‐reversal visual evoked potentials, and flash visual evoked potentials in 6 patients with clinically diagnosed Alzheimer's disease and 6 age and sex matched control subjects. The mean amplitude of the pattern‐reversal electroretinogram in the Alzheimer patients was significantly less than that of the control group (p = 0.004). This anomaly of the pattern‐reversal electroretinogram may be a reflection of documented axonal depletion within the optic nerve and the degeneration of retinal ganglion cells seen in Alzheimer's disease. We found Alzheimer patients to have normal pattern‐reversal visual evoked potentials and flash electroretinograms, but a delayed second positive component of the flash visual evoked potential. This combination of findings may be of diagnostic import in Alzheimers disease.