Electroretinographic signs of experimental chronic ischemia in the rabbit retina.

Chronic retinal ischemia was induced in rabbits by clamping the retrobulbar neurovascular pedicle of one eye. The other eye was used as a control. Electroretinograms (ERGs) were recorded for up to 32 weeks. The amplitude of the b-wave and of the oscillatory potentials showed a biphasic change: first a rapid drop below normal for 4 to 9 weeks, then an increase to above normal. The hyperresponsiveness was maintained up to the 32nd week. The implicit time of response was significantly modified only for the responses evoked by a low to moderate intensity of stimulation.