Purchase this article with an account.
S. Bolay, B. Falsini, S.R. Chamot, P.W. Ferrez, I. Questel, G.N. Lambrou, C.E. Riva; Blood Flow and ERG Responses to Luminance Flicker in Monkeys . Invest. Ophthalmol. Vis. Sci. 2003;44(13):351.
Download citation file:
© ARVO (1962-2015); The Authors (2016-present)
Purpose: In cats and humans, blood flow measured at the optic disc increases during luminance flicker-induced retinal neuronal stimulation (neuro-vascular coupling). As a prelude to the study of this coupling in monkeys with experimental glaucoma, we first investigated the flicker-induced blood flow and retinal ERG responses in the normal animal. Methods: In 6 cynomolgus monkeys, the blood flow response (RFonh) at the rim of the optic disc and the first (F1) and second (F2) harmonic amplitudes of the retinal electrical activity were simultaneously measured during sinusoidal luminance flicker by laser Doppler flowmetry and electroretinography, respectively. The effect of several flicker temporal frequencies (1 - 120 Hz), modulation depths (10 – 100%) and mean retinal illuminances (90 – 4420 Lux) was investigated. Results: In all animals, for 15Hz stimuli at a mean illuminance of 860 Lux, RFonh, F1 and F2 were linearly correlated to the modulation amplitude (r ≥ 0.959, N = 10). Both F1 and F2 were also linearly correlated to RFonh (r ≥ 0.889, N = 10). With 100% modulated stimuli at 860-Lux mean illuminance, both RFonh and F2 at various flicker frequencies showed a low frequency bandpass behavior, with a maximum at 8Hz of 22 ± 7% (mean ± 95% confidence interval) and 12 ± 5 µV, respectively. When the mean illuminance was varied, F1 was linearly correlated (r = 0.998, N = 8). Conclusions: The ONH blood flow and ERG responses to luminance flicker stimuli of various characteristics obtained in this investigation are very similar to those observed in humans and demonstrate the presence of a tight neuro-vascular coupling in normal monkeys. They will serve as reference in future studies of the impact of experimental glaucoma on this coupling.
This PDF is available to Subscribers Only