Electrophysiological visual field measurement

A method of measuring the electrophysiological visual field, comprising the steps of:

• placing a pair of electrodes around the inion on the scalp overlying the visual cortex of the brain, in addition to a ground electrode, where one or more additional bipolar electrodes are placed around the inion to record additional channels of data input,
• visually stimulating an eye;
• and,
• recording the data signals picked up by the electrodes,
• where the greatest amplitude derived from all recorded channels at each individual point of the visual field is determined, it is then assigned to that point as the optimal signal, and its amplitude used as a measure of response of the visual pathway.

A method of measuring the electrophysiological visual field, comprising the steps of:

• placing a pair of electrodes around the inion on the scalp overlying the visual cortex of the brain, in addition to a ground electrode;
• visually stimulating an eye;
• and,
• recording the data signals picked up by the electrodes,
• where a VEP trace from a particular sector of the combined trace array of one eye is compared to a VEP from the corresponding area of the fellow eye and an amplitude ratio is calculated.

A method of measuring the electrophysiological visual field, comprising the steps of:

• placing a pair of electrodes around the inion on the scalp overlying the visual cortex of the brain, in addition to a ground electrode;
• visually stimulating an eye;
• and,
• recording the data signals picked up by the electrodes,
• where a scaling algorithm is employed to normalise data, and
• where the scaling algorithm is based on calculation of the largest responses within the field compared to normal values for that particular point to produce a ratio, and the amplitudes of all points are then scaled up or down according to the ratio determined.