Recording neuromagnetic fields in retinitis pigmentosa.

After stimulation of the left and right half-fields, it is possible to record contralateral visually evoked neuromagnetic fields (VEF) without any reference to the size of the half-field stimulus display. The test reacts extremely sensitively upon each shifting of the half field into the periphery to the left or right. By application of half-field pattern stimuli of an extremely high or low spatial frequency, characteristic deviation angles are obtained for both the spatial frequencies after evaluation of the VEF amplitudes. By this method the foveal acuity in RP can be investigated with an objective procedure to a very high degree of accuracy.