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Biomedical Optics Express

Biomedical Optics Express

  • Editor: Joseph A. Izatt
  • Vol. 3, Iss. 12 — Dec. 1, 2012
  • pp: 3264–3277

Direct visualization and characterization of erythrocyte flow in human retinal capillaries

Phillip Bedggood and Andrew Metha  »View Author Affiliations

Biomedical Optics Express, Vol. 3, Issue 12, pp. 3264-3277 (2012)

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Imaging the retinal vasculature offers a surrogate view of systemic vascular health, allowing noninvasive and longitudinal assessment of vascular pathology. The earliest anomalies in vascular disease arise in the microvasculature, however current imaging methods lack the spatiotemporal resolution to track blood flow at the capillary level. We report here on novel imaging technology that allows direct, noninvasive optical imaging of erythrocyte flow in human retinal capillaries. This was made possible using adaptive optics for high spatial resolution (1.5 μm), sCMOS camera technology for high temporal resolution (460 fps), and tunable wavebands from a broadband laser for maximal erythrocyte contrast. Particle image velocimetry on our data sequences was used to quantify flow. We observed marked spatiotemporal variability in velocity, which ranged from 0.3 to 3.3 mm/s, and changed by up to a factor of 4 in a given capillary during the 130 ms imaging period. Both mean and standard deviation across the imaged capillary network varied markedly with time, yet their ratio remained a relatively constant parameter (0.50 ± 0.056). Our observations concur with previous work using less direct methods, validating this as an investigative tool for the study of microvascular disease in humans.

© 2012 OSA

OCIS Codes
(120.7250) Instrumentation, measurement, and metrology : Velocimetry
(170.1470) Medical optics and biotechnology : Blood or tissue constituent monitoring
(170.4470) Medical optics and biotechnology : Ophthalmology
(170.2655) Medical optics and biotechnology : Functional monitoring and imaging
(110.1080) Imaging systems : Active or adaptive optics

ToC Category:
Cardiovascular Applications

Original Manuscript: August 31, 2012
Revised Manuscript: October 8, 2012
Manuscript Accepted: November 13, 2012
Published: November 15, 2012

Phillip Bedggood and Andrew Metha, "Direct visualization and characterization of erythrocyte flow in human retinal capillaries," Biomed. Opt. Express 3, 3264-3277 (2012)

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