Browse by author
Lookup NU author(s): Professor Ted Sharpe
Full text for this publication is not currently held within this repository. Alternative links are provided below where available.
Multifocal electroretinograms (mfERG) were recorded from 38 normal trichromats with a pattern-reversing display that modulated only their long-wavelength sensitive (L) or only their middle-wavelength sensitive (M) cones at equal cone contrasts and average quantal catches. The display consisted of scaled, 103 hexagonal elements, subtending 84° × 75° of visual angle. Typically, the amplitude of the L-cone driven signal was greater than that for the M-cone driven one at all retinal eccentricities, but large differences were found among observers. These values correlated with L- to M-cone ratios obtained psychophysically in the same observers using 2° (dia.) heterochromatic flicker photometry. Interestingly, the L- to M-cone driven amplitude ratios differed between the central and peripheral retina. For the central fovea (5° dia.), the mean ratio was 1.4 ± 0.6 (for the N1P1 component), whereas for the annular ring centered at 40° in the periphery, it was 2.3 ± 2.0. The mean P1 latency of the summed M-cone driven mfERG (28.0 ± 2.6 ms) was significantly advanced relative to the L-cone driven signal (29.0 ± 1.9 ms), but the mean N1 latencies were similar (15.6 ± 1.7 ms and 16.2 ± 1.3 ms, respectively). The P1 latency difference between the L- and M-cone driven waveforms was not found in the central 5° (dia.) of the retina. However, it increased with retinal eccentricity. The regional differences in the amplitudes and latencies of the L- and M-cone driven mfERG signals can be related to variations in the L- to M-cone ratios and/or the receptor to bipolar gain factors that depend on eccentricity. © 2002 ARVO.
Author(s): Albrecht J, Jagle H, Hood DC, Sharpe LT
Publication type: Article
Publication status: Published
Journal: Journal of Vision
Year: 2002
Volume: 2
Issue: 8
Pages: 543-558
ISSN (print): 1534-7362
ISSN (electronic):
Publisher: Association for Research in Vision and Ophthalmology
URL: http://dx.doi.org/10.1167/2.8.2
DOI: 10.1167/2.8.2
PubMed id: 12678638
Altmetrics provided by Altmetric
