Electrophysiology in acute anterior ischaemic optic neuropathy.

In a retrospective study of 18 patients, in which 19 eyes were involved, we found in general during the acute phase of an anterior ischaemic optic neuropathy, i.e., within 4 weeks, markedly delayed and reduced pattern-evoked potentials, normal electroretinograms, and decreased electro-oculograms following light stimulation with normal standing potentials. Apart from some sclerosis of the vessels, no other abnormalities of the retinal circulation could be established in our patients. The explanation for the lowered light rise might be the partial and temporary disturbance of the choroidal circulation, which is not extensive enough to influence also the more variable standing potential. In long-standing cases the pattern-evoked potentials seem to remain abnormal, whereas the decreased electro-oculogram following light stimulation recovers.