Influence of diffuse luminance flicker on choroidal and optic nerve head blood flow

Purpose. In the retina there is general agreement that blood flow adapts in response to different conditions of light and darkness including diffuse luminance flicker. By contrast, regulation of choroidal blood flow in response to different light conditions is still a matter of controversy. Thus, we investigated the effect of diffuse luminance flicker on choroidal and optic nerve head blood flow. Methods. In a group of 14 healthy volunteers, choroidal blood flow and ocular fundus pulsation amplitude were assessed with laser Doppler flowmetry and laser interferometry, respectively. Measurements were done before, during and after stimulation with diffuse luminance flicker. Furthermore, the response of optic nerve head blood flow (ONHBF) to flicker stimulation was measured. Flicker stimuli were generated by a Grass® PS2 photostimulator, stimulating at a frequency of 8 Hz. Flicker light consisted of light flashes at a wavelength below 550nm and produced a retinal irradiance of 140 µW/cm 2. Blood pressure and ...