Author/Editor | Šuštar, M; Hawlina, M; Brecelj, J | |
Title | ON- and OFF-response of the photopic electroretinogram in relation to stimulus characteristics | |
Type | članek | |
Source | Doc Ophthalmol | |
Vol. and No. | Letnik 113, št. 1 | |
Publication year | 2006 | |
Volume | str. 43-52 | |
Language | eng | |
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/m(2), the background luminance from 20 to 50 cd/m(2) 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/m(2)) broadened the b-wave and increased variability of its implicit time. With a brighter background (50 cd/m(2)) 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. | |
Descriptors | ELECTRORETINOGRAPHY PHOTIC STIMULATION |