Is white the right light for the clinical electrooculogram?

ABSTRACT

PURPOSE: To investigate if a lower luminance monochromatic LED stimulus could be used as an alternative to a high luminance white light for the clinical electrooculogram. METHODS: Clinical electrooculograms were recorded in color normal participants (N = 23) aged 22.6 ± 1.2 years, 7 male and 16 female using the standard 100 cd.m-2 white illuminant and four monochromatic LEDs with peak wavelengths of 448, 534, 596 and 634 nm at 30 cd.m-2. Pupils were dilated and there was a 30 cd.m-2pre-adaptation to white light for 2 min followed by 15 min dark adaptation and 20 min recording in the light stimulus using a Ganzfeld stimulator. RESULTS: The normalized LPDTratio for the short wavelength LED (448 nm) was equivalent in amplitude and timing to the ISCEV standard EOG (p = .99). The LPDTratio for the white (100 cd.m-2) and 448 nm (30 cd.m-2) were (median ± SEM) 2.49 ± .11 and 2.47 ± .11. The time to light-rise peak was also equivalent being 9.0 ± .2 and 8.0 ± .4 min (p = .54). CONCLUSIONS: Consideration may be given to using a short wavelength monochromatic stimulus that is more comfortable for the subject than the current 100 cd.m-2 illuminant.