[The reproducibility of multifocal ERG recordings].
OBJECTIVE
Multifocal electroretinogram recordings (mfERG) can be used to detect a local dysfunction of the retina. In this study we tested both the intrasessional and inter-sessional reproducibility of mfERG amplitudes.


METHODS
MfERGs from 6 eyes of 6 normal subjects were recorded on two different days using DTL electrodes. The relative coefficient of variation ( RCV) was used to quantify the amplitude reproducibility. We tested the effect of (a) session (inter- vs. intrasessional), (b) recording duration (7.3 vs. 3.6 min), (c) trace type (hexagon traces vs. ring averages), and (d) amplitude definition (peak-trough analysis vs. scalar product) on RCV.


RESULTS
RCV was 6.5+/-0.4% (Mean+/-SEM, n=96) when averaged across all recording conditions and all subjects. The ANOVA showed a significant difference ( p=0.018) between hexagon traces and ring averages. Another significant effect ( p=0.016) occurred for the interaction of (a) and (b).


CONCLUSIONS
MfERGs can be recorded with a high degree of reproducibility even for short recording durations and single hexagon traces. As the factor (a) did not show a significant effect, the new placement of the DTL electrode in the second session does not necessarily increase the retest variability compared to a second recording within the same session.
Meigen
T
T
Universitäts-Augenklinik Würzburg. t.meigen@augenklinik.uni-wuerzburg.de
Friedrich
A
A
D016477:Artifacts; D003627:Data Interpretation, Statistical; D004596:Electroretinography / Q000295:instrumentation*; D006801:Humans; D012016:Reference Values; D015203:Reproducibility of Results; D012815:Signal Processing, Computer-Assisted / Q000295:instrumentation*; D012984:Software