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

Abstract

PurposeTo 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.MethodsThis 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.ResultsArtifact-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.ConclusionsLSFG 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.

Effects of water drinking test on ocular blood flow waveform parameters: A laser speckle flowgraphy study

“…Furthermore, they suggested that tissue area falling rate is the only independent factor indicating age. Luft et al reproduced the same results for white subjects of Western European descent [50]. Our study also indicates significant increase in falling rate, and decrease in BOT in tissue area 10 minutes after water intake.…”

“…Furthermore, rising rate has also been found significant at 20 and 60 minutes after WDT. Luft et al have presented that the rising rate must be carefully considered pertaining to its moderate level of repeatability [50]. We have also observed an irregular trend for rising rate.…”

Pulse Waveform Analysis in Ocular Microcirculation by Laser Speckle Flowgraphy in Patients with Left Ventricular Systolic and Diastolic Dysfunction

“…A similar explanation for the rising rate and BOS values was obtained from the waveform analysis [19, 22, 32, 33]. All of the measurements were taken with the patients in the seated position, and pupils were dilated with 0.5% tropicamide eye drops.…”

“…In light of those findings, we hypothesized that the pulse waveform obtained from LSFG may reflect not only peripheral vascular dynamics but also cardiac vasculature dynamics. It was reported that the coefficient of variance for the rising rate and BOS measured by LSFG under pupil dilation were 2.62 and 5.67, respectively [33]. Thus, the rising rate and BOS, which comprise the pulse waveform of LSFG, have a highly reproducibility.…”

Ocular microcirculation measurement with laser speckle flowgraphy and optical coherence tomography angiography in glaucoma

“…,b; Luft et al. ,b). Laser speckle flowgraphy has contributed to our understanding of the association of ocular BF with glaucoma pathophysiology by showing that MBR is associated with structure and function in glaucoma (Aizawa et al.…”