The value of ophthalmodynamometry as a diagnostic aid in carotid artery disease has been established and so have its limitations.1-6
The use of electroretinography for clinical evaluation of the carotid artery system was suggested by previous studies in animals7,8 and in 1 human subject.9 Granit demonstrated a selective disappearance of the b-wave during carotid compression in cats.7 The b-wave resumed a normal amplitude after release of the compression. Horsten and Winkelman showed a gradual, complete disappearance of the a- and b-wave in cats with carotid clamping for 7½ to 15 minutes.8 After release of the clamp, both waves reappeared; however, these were sometimes of smaller amplitude than before clamping, suggesting permanent retinal damage. The greater sensitivity of the b-wave to retinal ischemia was suggested by the faster disappearance and slower reappearance. Kriz found a consistently larger ERG from the right eye