title: ON- and OFF-response of the photopic electroretinogram in relation to stimulus characteristics.
abstract: The aim of this study was to explore the effect of stimulus duration, stimulus intensity, stimulus wavelength and background luminance on the amplitude and waveform of the ON- (b-wave) and OFF- (d-wave) response of the photopic ERG. The following parameters were used in this study: stimulus duration from 5 to 200 ms, the flash intensities from 0.4 to 2.1 log cd s/m2, the background luminance from 20 to 50 cd/m2 and stimulus wavelengths 460, 508 and 667 nm. Prolonging the stimulus duration from 75 to 200 ms did not influence the amplitudes of a-, b- and d-waves significantly. Higher stimulus intensities (1.9 log cd s/m2) broadened the b-wave and increased variability of its implicit time. With a brighter background (50 cd/m2) the b-wave did not broaden and its optimal amplitude was preserved. Stimuli of longer wavelengths (667 nm) significantly reduced the d-wave amplitude. Our results suggest that high intensities and longer wavelengths (red) may not be suitable stimulus parameters in the routine clinical ON- and OFF-response recording.
authors.affiliation: Eye Clinic, University Medical Centre, Zaloska 29/a, 1000, Ljubljana, Slovenia. maja.sustar@kclj.si
authors.forename: Maja
authors.initials: M
authors.lastname: Sustar
authors.forename: Marko
authors.initials: M
authors.lastname: Hawlina
authors.forename: Jelka
authors.initials: J
authors.lastname: Brecelj
mesh_terms: D000328:Adult; D004594:Electrophysiology; D004596:Electroretinography; D006801:Humans; D010775:Photic Stimulation; D012160:Retina / Q000502:physiology* / Q000528:radiation effects