Purchase this article with an account.
E. Logean, B. Falsini, C.E. Riva; Characteristics of the Optic Nerve Head Blood Flow Response to Flicker Stimulation of the Retina . Invest. Ophthalmol. Vis. Sci. 2003;44(13):350.
Download citation file:
© ARVO (1962-2015); The Authors (2016-present)
Purpose: To establish the time course, magnitude and reproducibility of optic nerve blood velocity (Vel), volume (Vol) and flow (F) in response to luminance flicker in normal subjects. Methods: In 15 subjects (28-63 years), Vel, Vol and F (LDF parameters) were continuously recorded by near-infrared laser Doppler flowmetry from temporal sites of the optic disk. Stimuli consisted of 15-Hz green diffuse flicker (field of 30°, 13 lux, duration 50s). Magnitude (M) of the responses were expressed as the % change between the mean of the values during the last 20 s of flicker and the mean of those during the last 20 s of baseline. Time constant (τ) of the group average increases in the LDF parameters in response to flicker were determined. Intra-subject coefficients of variation (CV) were obtained for 6 successive F-responses (RF) (1 subject) and multiple RFs recorded over a 3 months period (2 subjects). Fatigue effects of the flicker-induced LDF parameter responses were assessed based on 8-11 min stimulation. Results: Group average (± 95% CL) of all LDF parameters increased during flicker (p<0.00002, Table). Intra-subject CV for 6 recordings was 26% for RF and CVs for 2 subjects (3 months) were 25 and 50%. We found no dependence of RF on the pre-stimulus F and no fatigue effect on RF. Conclusions: RF is predominately determined by changes in blood volume, suggesting that the increase in flow is mainly due to a local vasodilatation or capillary recruitment during flicker. The time courses of the flow parameters are similar to those found in the human cortex in response to visual stimulation. View OriginalDownload SlideView OriginalDownload Slide
This PDF is available to Subscribers Only