Photo-evoked eyelid microvibration (blink reflex elicited by flash stimuli) in newborns and children

The orbicularis oculi muscle contracts in response to photic stimulation. It was recorded as the microvibration of the eyelid contraction and it is called the photo-evoked eyelid microvibration (MV). MV was recorded using a special transducer on the central part of the upper eyelid from 167 subjects free of any neurological abnormalities. One G of the vibration was converted into 100 mV. The normal value was shown in newborns and children. The latency was 171.0 +/- 30.5 msec in newborns, 70.3 +/- 12.3 msec in 4 to 5 year-olds, 46.3 +/- 11.2 msec in 7 to 8 year-olds and 57.0 +/- 4.9 msec in adults. The latency of MV became shortened with growth. It is thought that the shortening of the latency during maturation is related to the myelination of the brainstem reticular formation and the maturation of the retina.