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) Submit a response Alert me when this article is cited Alert me when eLetters are posted Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal 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 Google Scholar Google Scholar Articles by Lovasik, J. V. Articles by Geiser, M. Search for Related Content PubMed PubMed Citation Articles by Lovasik, J. V. Articles by Geiser, M.

Choroidal Blood Flow during Exercise-Induced Changes in the Ocular Perfusion Pressure

¹From the School of Optometry, University of Montréal, Montréal, Québec, Canada; the ²Institute of Research in Ophthalmology, Sion, Switzerland; and the ³Faculty of Medicine, University of Lausanne, Lausanne, Switzerland.

PURPOSE. The high metabolic rate of the human retina is supported by the choroidal vasculature. Knowledge of the normal choroidal blood flow (ChBF) responses to various physiological stimuli is therefore highly important if the pathophysiology of ocular diseases involving the choroid is to be understood better. In the present study, the hemodynamic responses of the subfoveal ChBF were examined during and after an exercise-induced increase in the ocular perfusion pressure (OPP).

METHODS. Twenty-six healthy volunteers, 19 to 55 years of age participated in this two-phase study. Each subject increased resting OPP through stationary biking at a heart rate (HR) of 140 beats per minute (bpm) over 20 minutes. The ChBF was measured by laser Doppler flowmetry (LDF), the systemic BP by electronic sphygmomanometry, and the resting intraocular pressure (IOP) by applanation tonometry.

RESULTS. The OPP increased by approximately 43% at the onset of biking, and then decreased biphasically to approximately 12% above resting value by the end of biking. The ChBF remained within 10% of its basal value throughout biking. Immediately after biking, the OPP decreased twice as much as the ChBF in the same time frame.

CONCLUSIONS. The dissociation between the OPP and the ChBF during biking and recovery suggests that some mechanism keeps the ChBF close to its basal value, an observation that indicates blood flow regulation.

This article has been cited by other articles:

				L. A. Jones, L. T. Sinnott, D. O. Mutti, G. L. Mitchell, M. L. Moeschberger, and K. Zadnik Parental History of Myopia, Sports and Outdoor Activities, and Future Myopia Invest. Ophthalmol. Vis. Sci., August 1, 2007; 48(8): 3524 - 3532. [Abstract] [Full Text] [PDF]

				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]

				A. M. Pauli, E. Bentley, K. A. Diehl, and P. E. Miller Effects of the application of neck pressure by a collar or harness on intraocular pressure in dogs. J. Am. Anim. Hosp. Assoc., May 1, 2006; 42(3): 207 - 211. [Abstract] [Full Text] [PDF]

				J. V. Lovasik, H. Kergoat, and M. A. Wajszilber Blue flicker modifies the subfoveal choroidal blood flow in the human eye Am J Physiol Heart Circ Physiol, August 1, 2005; 289(2): H683 - H691. [Abstract] [Full Text] [PDF]

				S. Jean-Louis, J. V. Lovasik, and H. Kergoat Systemic Hyperoxia and Retinal Vasomotor Responses Invest. Ophthalmol. Vis. Sci., May 1, 2005; 46(5): 1714 - 1720. [Abstract] [Full Text] [PDF]

				A. Longo, M. H. Geiser, and C. E. Riva Posture Changes and Subfoveal Choroidal Blood Flow Invest. Ophthalmol. Vis. Sci., February 1, 2004; 45(2): 546 - 551. [Abstract] [Full Text] [PDF]