Ocular Blood Flow Measurements in Healthy White Subjects Using Laser Speckle Flowgraphy

• Published in: PloS one Vol. 11; no. 12; p. e0168190
• Main Authors: Luft, Nikolaus, Wozniak, Piotr A., Aschinger, Gerold C., Fondi, Klemens, Bata, Ahmed M., Werkmeister, René M., Schmidl, Doreen, Witkowska, Katarzyna J., Bolz, Matthias, Garhöfer, Gerhard, Schmetterer, Leopold
• Format: Journal Article
• Language: English
• Published: United States Public Library of Science 13.12.2016; Public Library of Science (PLoS)
• Subjects: Adolescent; Adult; Age; Age Factors; Aged; Analysis; Bioindicators; Biology and Life Sciences; Biomarkers; Biomedical engineering; Blood; Blood flow; Blood Flow Velocity - physiology; Blood Pressure - physiology; Correlation coefficient; Correlation coefficients; Cross-Sectional Studies; Diabetic retinopathy; Dilation; Engineering; Engineering and Technology; European Continental Ancestry Group; Eye (anatomy); Feasibility studies; Female; Flow velocity; Glaucoma; Health physics; Healthy Volunteers; Hemodynamics; Hospitals; Humans; Hypotheses; Image analysis; Image processing; Image Processing, Computer-Assisted; Image quality; Laser speckle; Laser-Doppler Flowmetry; Lasers; Male; Measurement; Medicine and Health Sciences; Microcirculation - physiology; Middle Aged; Optic Disk - blood supply; Optic nerve; Optics; Patients; People and Places; Perfusion; Pharmacology; Physical Sciences; Physics; Pigmentation; Pupil - physiology; Regional Blood Flow - physiology; Reliability analysis; Reproducibility; Reproducibility of Results; Sex Factors; Smoking; Time Factors; Velocity; Young Adult; Japan; Austria; Singapore; United States > US; Baltimore Maryland
• ISSN: 1932-6203; 1932-6203
• DOI: 10.1371/journal.pone.0168190

To assess the feasibility and reliability of Laser Speckle Flowgraphy (LSFG) to measure ocular perfusion in a sample of healthy white subjects and to elucidate the age-dependence of the parameters obtained. This cross-sectional study included 80 eyes of 80 healthy, non-smoking white subjects of Western European descent between 19 and 79 years of age. A commercial LSFG instrument was applied to measure ocular blood flow at the optic nerve head (ONH) three successive times before and after pharmacological pupil dilation. The mean blur rate (MBR), a measure of relative blood flow velocity, was obtained for different regions of the ONH. Eight parameters of ocular perfusion derived from the pulse-waveform analysis of MBR including blowout time (BOT) and falling rate (FR) were also recorded. Artifact-free LSFG images meeting the quality criteria for automated image analysis were obtainable in 93.8% without pupil dilation and in 98.8% with pharmacological pupil dilation. Measurements of MBR showed excellent repeatability with intraclass correlation coefficients ≥ 0.937 and were barely affected by pupil dilation. The majority of pulse-waveform derived variables exhibited equally high repeatability. MBR-related blood flow indices exhibited significant age dependence (p<0.001). FR (r = 0.747, p<0.001) and BOT (r = -0.714, p<0.001) most strongly correlated with age. LSFG represents a reliable method for the quantitative assessment of ocular blood flow in white subjects. Our data affirms that the LSFG-derived variables FR and BOT may be useful biomarkers for age-related changes in ocular perfusion.