Clinical electro-oculography.

Electro-oculography (EOG), a retinal function test, indirectly records slow, light-induced changes in the potential difference between the anterior and posterior poles of the eye. EOG is a valuable clinical tool in diagnosis of tapetoretinal degenerations, vitelliform foveal dystrophy including the carriers of this disease, retinal intoxications and in differential diagnosis of choroidal malignant melanomas. EOG is not an alternative to electroretinography but yields additional information on the function of the retinal pigment epithelium. The main drawback of the present technique is the high inter- and intraindividual variability of the results.