The Visual evoked Potential in Patients with Cataracts

Abstract

Of recent years there has been a marked emphasis on the use of pattern reversal as the appropriate stimulus for studies of the Visual Evoked Potential (VEP), particularly in normal subjects or co-operative adult patients. Early studies of the clinical value of the VEP usually used flash as the stimulus, but the inherent crudity of an undifferentiated flash of light discouraged many workers from continuing with this stimulus or from using flashed patterns as an alternative stimulus. However, as we indicated in previous studies (Harding et al., 1970), the flash evoked potential is most useful in identifying gross field defects in patients who cannot or will not fixate a pattern. Thus, the technique is of use in very young children, grossly handicapped patients, and in conditions of opacity of the eye. Dense opacities of the optic media prevent full clinical assessment of the retina, and there is, therefore, a problem of whether cataract surgery will result in improved vision.