Clocking the conduction velocity of the visual pathway with optically pumped magnetometers

The human visual pathway carries high volumes of information from the retina to distant regions of visual cortex.

The speed of this information transfer, retinocortical conduction time, has been proposed as a diagnostic measure of neurodegeneration.

This conduction time has typically been estimated based on relatively slow evoked responses, although we now know that high-frequency activity in both the retina and visual cortex precede slower evoked responses by several tens of milliseconds.

In addition, the difference in timing between the onset of high-frequency activity in the retina and cortex is more in line with the expected conduction velocities of the heavily myelinated visual pathway.This project proposes to develop and validate a new sensor technology, optically pumped magnetometers (OPMs), to measure this high-frequency retinocortical conduction time, with a view towards establishing a diagnostic suitable for patients in the neurology and eye clinics to assess disease progression.

Impacts to myelination, circulation, and neural connectivity are all expected to reduce the conduction speed of the visual pathway, even before visual symptoms become apparent.

The proposed high-frequency conduction time technique should provide a more accurate and sensitive measure to detect these impacts, with high potential for translation into a clinical diagnostic method.

We will furthermore streamline the measurement procedure to increase the comfort, duration, and feasibility for potential patient groups.