see Intraoperative Visual Evoked Potential Monitoring.

VEP measures the functional integrity of the optic pathways from the retina to the brain's visual cortex in response to light stimulus. Visual stimulus is converted into nerve signals in the retina. These signals are transmitted via the optic pathway to the brain, from the retina to the optic nerve, optic chiasma, optic tract, lateral geniculate body, optic radiation, and visual cortex occipital lobe ¹⁾.

mfVEP, SAP, and OCT provide complementary information for detecting visual pathway abnormalities in patients with pituitary neuroendocrine tumors. Good agreement was demonstrated between SAP and mfVEP and quantitative analysis of structure-function measurements revealed a moderate correlation.