Abnormal pattern electroretinograms in patients with senile dementia of the Alzheimer type.

Patients with senile dementia of the Alzheimer type frequently have difficulty performing visual tasks. These difficulties may be due, at least partially, to degenerative changes in both the primary visual pathway and the visual association areas. To determine whether retinal ganglion cell dysfunction contributes to visual loss in senile dementia of the Alzheimer type, we tested a group of patients with this disease (n = 13) using the pattern-reversal electroretinogram to both low (4.0 reversals per second) and high (16.0 reversals per second) temporal frequency checkerboard patterns (1.0 degree checks). Significant amplitude reductions were noted for the patients relative to age-matched control subjects (n = 30). In addition, the observed amplitude reductions were most pronounced for the high temporal frequency condition. Therefore, the results are consistent with retinal ganglion cell dysfunction and support the notion that optic nerve damage induced by senile dementia of the Alzheimer type preferentially affects the larger, faster-conducting retinal ganglion cells along with their retinocortical projections.