The monocularly elicited visual evoked response in chronic glaucoma

The monocularly elicited transscleral visual evoked cortical response was measured in a group of patients with asymmetric visual field loss due to chronic open-angle glaucoma. It was established that the visual field loss in the 2 eyes was statistically different in the patients. In addition, the peak amplitude of the visual evoked response obtained from a common occipital cortical position was statistically different when the 2 eyes were separately stimulated. A good linear correlation was found between the amplitude of the monocular transscleral visual evoked response and the amount of visual field remaining on tangent screen perimetry. The best correlation was found when a red stimulus was used to elicit the VER. The monocularly elicited visual evoked response provides an objective measurement of visual field in chronic open-angle glaucoma. It has value in those patients who have asymmetric disease and who are unable to provide reliable subjective responses. It may be useful in such patients to follow progression of the glaucomatous process.