Pattern electroretinograms (PERGs) were recorded from two normal human subjects in response to various spatial frequencies and stimulus areas. The maximum stimulus area was 75 ~ x 86 ~ which was achieved by using a standard TV monitor and a reduced viewing distance. The amplitude of the PERG increas
Variability of the pattern electroretinogram
โ Scribed by Karen Holopigian; Jeremy Snow; William Seiple; Irwin Siegel
- Publisher
- Springer-Verlag
- Year
- 1988
- Tongue
- English
- Weight
- 602 KB
- Volume
- 70
- Category
- Article
- ISSN
- 0012-4486
No coin nor oath required. For personal study only.
โฆ Synopsis
Conflicting results have been obtained concerning the parametric properties of the pattern electroretinogram. These discrepancies may be due to the large amount of variability inherent in recording amplitudes. We have found the variability within a single stimulus condition to be so large (ranging from 30% to 67% of the mean value) that it could mask any underlying spatial frequency tuning. Changing the stimulus conditions failed to significantly reduce the observed variability, although changing recording conditions produced some reduction. The use of a narrower rejection band, a greater number of sweeps, and placement of the reference electrode on the ipsilateral ear (as opposed to the ipsilateral temple) combined to decrease variability of the pattern electroretinogram within a single recording session; however, intersession variability remained high. Therefore one must be careful in evaluating data from this technique, and caution is advised in its clinical use.
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