The effect of time of day and repeat reliability on the fast flicker multifocal ERG.
OBJECTIVE
To investigate the possible influence of different times of the day on multifocal ERG recordings in normals.


METHODS
10 healthy volunteers underwent multifocal ERG recordings (VERIS 3.1.1.) 3 times a day, at 10:30 am, 1:30 pm and 4:30 pm using a fast flicker stimulus of 103 hexagons. Additional night-time recordings were performed in 2 subjects. The first-order and dominant part of the second order response component were analyzed.


RESULTS
Neither peak latencies nor peak-to-peak amplitudes showed significant changes during the day (p >0.05). Comparison between night and day time recordings did also not reveal an influence of a circadian rhythm on the MF-ERG.


CONCLUSIONS
No significant influence of the time of the day suggestive of a circadian rhythm could be observed. Light adaptation due to preadaptation and the flicker sequence used could be a possible cause for these results.
Heinemann-Vernaleken
B
B
Department of Ophthalmology and Eye Hospital, University of the Saarland, Homburg, Germany. aubhei@med-rz.uni-sb.de
Palmowski
A
A
Allgayer
R
R
D000221:Adaptation, Ocular / Q000502:physiology*; D000328:Adult; D002940:Circadian Rhythm / Q000502:physiology*; D004596:Electroretinography; D005260:Female; D006801:Humans; D008297:Male; D015203:Reproducibility of Results; D012160:Retina / Q000502:physiology*; D013997:Time Factors