May 2007
Volume 48, Issue 13
ARVO Annual Meeting Abstract  |   May 2007
Evaluation of Quantitative Indexes for the Analysis of Multifocal ERG
Author Affiliations & Notes
  • J. R. Charlier
    Research, Metrovision, Perenchies, France
  • S. Defoort-Dhelemmes
    Ophthalmology, Lille University Medical Center, Lille, France
  • X. Zanlonghi
    Ophthalmology, Clinique Sourdille, Nantes, France
  • Sé. Vermandel
    Research, Metrovision, Perenchies, France
  • Footnotes
    Commercial Relationships J.R. Charlier, metrovision, E; S. Defoort-Dhelemmes, None; X. Zanlonghi, None; S. Vermandel, metrovision, E.
  • Footnotes
    Support None.
Investigative Ophthalmology & Visual Science May 2007, Vol.48, 5993. doi:
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      J. R. Charlier, S. Defoort-Dhelemmes, X. Zanlonghi, Sé. Vermandel; Evaluation of Quantitative Indexes for the Analysis of Multifocal ERG. Invest. Ophthalmol. Vis. Sci. 2007;48(13):5993.

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      © ARVO (1962-2015); The Authors (2016-present)

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Purpose:: To evaluate the clinical applicability of quantitative indexes for the interpretation of multifocal ERG (MfERG) exams. These indexes have been developed to improve the detection of alterations of MfERG responses. A first set of indexes compares the amplitudes of P1 (related to the activity of inner layers) to the amplitude of N1 (related to the activity of photoreceptors). A second set of indexes compares the amplitudes of central responses to peripheral responses.

Methods:: MfERG exams were performed with identical conditions over a reference group of 71 eyes from normal individuals and over a pathological group of 32 eyes with various diseases of the retina. The analysis included: the amplitude of averaged responses over 5 ring areas (0-2, 2-5, 5-10, 10-15 and 15-25 degrees eccentricity). P1/N1 was computed for each averaged response. N1/N1 periphery and P1/P1 periphery were computed for the 4 central rings.

Results:: Reference group: variation coefficients were 21% for N1 amplitude, 19% for P1 amplitude. P1/N1 and P1/P1periphery were found to present much lower variation coefficients with values of 12% and 11%, respectively. Pathological group: In 11 cases out of 32, the spread of deficits was larger with N1/N1periphery than with N1 amplitude alone. In 14 cases out of 32, the spread of deficits was larger with P1/P1periphery than with P1 amplitude alone. In 10 cases P1/N1 was out of the normal range. 3 of these cases had no significant alterations of N1 and P1 amplitudes (1 chloroquine and 2 sabril intoxications).

Conclusions:: The use of quantitative indexes such as P1/N1 and P1/P1 periphery can significantly improve the detection and interpretation of alterations of MfERG results.

Keywords: electroretinography: clinical • electrophysiology: clinical 

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