title: Motion-onset visual evoked potentials improve the diagnosis of glaucoma.
abstract: Chronic glaucoma has been shown preferentially to damage larger retinal cells and optic nerve fibres that provide the input to the magnocellular visual pathway. We compared the motion-onset visual evoked potentials (primarily the magnocellular system) with those to standard pattern reversal in 20 patients with bilateral chronic glaucoma. For motion-onset visual evoked potentials, the pattern (isolated 40' checks of 10% contrast) moved in four cardinal directions (varied randomly from trial to trial) at a velocity of 10 deg/s for 20 ms, with an interstimulus interval of 1 s. In pattern-reversal stimulation, the checkerboard reversed at a rate of 2 reversals per second. In 60% of the eyes investigated, the results of both types of visual evoked potentials correlated, showing either normal (27.5%) or increased (32.5%) latencies. In the remaining 40% of the eyes, the normal pattern-reversal visual evoked potential latencies were accompanied by prolonged motion-onset visual evoked potentials. The high occurrence of delayed motion-onset visual evoked potentials in our patients confirms the primary magnocellular loss in chronic glaucoma and suggests that the motion-onset VEPs are suitable for detection of glaucomatous changes.
authors.affiliation: Department of Physiology, Medical Faculty of Charles University, Hradec Králové, Czech Republic.
authors.forename: Z
authors.initials: Z
authors.lastname: Kubová
authors.forename: M
authors.initials: M
authors.lastname: Kuba
authors.forename: J
authors.initials: J
authors.lastname: Hrochová
authors.forename: J
authors.initials: J
authors.lastname: Svĕrák
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D002908:Chronic Disease; D003118:Color Perception / Q000502:physiology; D005074:Evoked Potentials, Visual / Q000502:physiology*; D005260:Female; D005901:Glaucoma / Q000175:diagnosis* / Q000503:physiopathology; D006801:Humans; D008297:Male; D008875:Middle Aged; D009039:Motion Perception / Q000502:physiology*; D009898:Optic Disk / Q000473:pathology / Q000503:physiopathology; D014792:Visual Acuity; D058609:Visual Field Tests; D014794:Visual Fields; D014795:Visual Pathways / Q000502:physiology