HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text Full Text (PDF) All Versions of this Article: 289/2/H683    most recent 01187.2004v1 Alert me when this article is cited Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in ISI Web of Science Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via ISI Web of Science (2) Citing Articles via Google Scholar Google Scholar Articles by Lovasik, J. V. Articles by Wajszilber, M. A. Search for Related Content PubMed PubMed Citation Articles by Lovasik, J. V. Articles by Wajszilber, M. A.

Blue flicker modifies the subfoveal choroidal blood flow in the human eye

École d'Optométrie, Université de Montréal, Montréal, Québec, Canada

Submitted 30 November 2004 ; accepted in final form 25 March 2005

The objective of the present study was to reveal an interaction between choroidal blood flow (ChBF) and light-induced photoreceptor activity, a physiological coupling that has been already demonstrated for retinal blood flow but rejected for ChBF. Ten healthy adults volunteered for this study. A real-time recording near-infrared laser-Doppler flowmeter was used to quantify the subfoveal ChBF while the luminance of blue flicker between 1 and 64 Hz was first increased and then decreased by 4.0 log units in 1.0-log unit steps between 0.0375 and 375 cd/m². In separate testing, flash electroretinograms (ERGs) provided electrophysiological indexes of the relative response of short-wave cones (s-cones) and rods to blue light stimulation. Group-averaged, normalized ChBF measurements revealed that it was modulated by 9% by flicker frequency. Increasing the blue flicker luminance from low to high attenuated the subfoveal ChBF, volume, and velocity by 32%, 30%, and 5%, respectively. Decreasing the luminance from high to low over the same range had no effect on the subfoveal choroidal hemodynamics. The markedly different effects of reversed directions of change in blue flicker luminance on the subfoveal ChBF were linked to transitions between rod-dominated and s-cone-dominated retinal responses. Collectively, these findings indicate that the blue light-induced photoreceptor response is associated with a differential distribution of the ChBF across the ocular fundus according to the degree and type of retinal photoreceptor stimulated.

blue-flash electroretinogram; choroidal blood flow; choroidal hemodynamics; laser-Doppler flowmetry; neural retinal activity

This article has been cited by other articles:

				H. Kergoat, M.-E. Herard, and M. Lemay RGC Sensitivity to Mild Systemic Hypoxia Invest. Ophthalmol. Vis. Sci., December 1, 2006; 47(12): 5423 - 5427. [Abstract] [Full Text] [PDF]