Abstract

Neurovascular coupling is a vital mechanism employed by the cerebrovascular system, including the eye, to regulate blood flow in periods of neuronal activation. This study aims to investigate if laser speckle flowgraphy (LSFG) can detect coupling response elicited by flickering light stimuli and how variations in stimulus type and duration can affect the magnitude and evolution of blood flow in the optic nerve head (ONH) and peripapillary vessels. Healthy adults were exposed to two types of 10-Hz flicker stimuli: a photopic negative response-like stimulus (PhNR-S) or a visual evoked potential-like stimulus (VEP-S)—each presented in separate 10- and 60-s epochs. Both PhNR-S and VEP-S significantly increased ONH blood flow (p < 0.001) immediately after flicker cessation, with a trend of 60-s stimuli (PhNR-S = 11.6%; VEP-S = 10.4%) producing a larger response than 10-s stimuli (PhNR-S = 7.5%; VEP-S = 6.2%). Moreover, exposure to 60-s stimuli elicited a significantly prolonged ONH hyperemic response, especially with PhNR-S. Lastly, stimulation with either 60-s stimuli elicited a robust increase in blood flow within the peripapillary arterioles (p < 0.01) and venules (p < 0.01) as well. Flicker stimulation with common visual electrophysiology stimuli (PhNR-S and VEP-S) induced a demonstrable increase in ONH and peripapillary vessel blood flow, which varied with flicker duration. Our results validate that LSFG is a robust method to quantify flicker-induced hyperemic responses and to study neurovascular coupling in humans.

Details

Title
Stimulus type and duration affect magnitude and evolution of flicker-induced hyperemia measured by laser speckle flowgraphy at the optic disc and peripapillary vessels
Author
Aung, Moe H. 1 ; Aleman, Tomas S. 2 ; Garcia, Arielle S. 3 ; McGeehan, Brendan 4 ; Ying, Gui-Shuang 4 ; Avery, Robert A. 5 

 The Perelman School of Medicine at the University of Pennsylvania, Departments of Neurology, Philadelphia, USA (GRID:grid.25879.31) (ISNI:0000 0004 1936 8972); Dell Medical School at The University of Texas at Austin, Department of Ophthalmology, Austin, USA (GRID:grid.89336.37) (ISNI:0000 0004 1936 9924) 
 The Perelman School of Medicine at the University of Pennsylvania, Department of Ophthalmology, Philadelphia, USA (GRID:grid.25879.31) (ISNI:0000 0004 1936 8972); The Children’s Hospital of Philadelphia, Division of Ophthalmology, Philadelphia, USA (GRID:grid.239552.a) (ISNI:0000 0001 0680 8770) 
 The Children’s Hospital of Philadelphia, Division of Ophthalmology, Philadelphia, USA (GRID:grid.239552.a) (ISNI:0000 0001 0680 8770) 
 The Perelman School of Medicine at the University of Pennsylvania, Department of Ophthalmology, Philadelphia, USA (GRID:grid.25879.31) (ISNI:0000 0004 1936 8972) 
 The Perelman School of Medicine at the University of Pennsylvania, Departments of Neurology, Philadelphia, USA (GRID:grid.25879.31) (ISNI:0000 0004 1936 8972); The Perelman School of Medicine at the University of Pennsylvania, Department of Ophthalmology, Philadelphia, USA (GRID:grid.25879.31) (ISNI:0000 0004 1936 8972); The Children’s Hospital of Philadelphia, Division of Ophthalmology, Philadelphia, USA (GRID:grid.239552.a) (ISNI:0000 0001 0680 8770) 
Pages
6659
Publication year
2024
Publication date
2024
Publisher
Nature Publishing Group
e-ISSN
20452322
Source type
Scholarly Journal
Language of publication
English
ProQuest document ID
2969631643
Copyright
© The Author(s) 2024. This work is published under http://creativecommons.org/licenses/by/4.0/ (the “License”). Notwithstanding the ProQuest Terms and Conditions, you may use this content in accordance with the terms of the License.