Evaluation of Fundus Blood Flow in Normal Individuals and Patients with Internal Carotid Artery Obstruction Using Laser Speckle Flowgraphy

<div><p>Purpose</p><p>We investigated whether laser speckle flowgraphy (LSFG) results are comparable in both eyes and whether it is useful in the diagnosis of disparity in ocular ischemic syndrome (OIS) patients.</p><p>Methods</p><p>We compared the mean blur rate (MBR) value for various fundus regions in both eyes of 41 healthy subjects and 15 internal carotid artery occlusion (ICAO) cases. We calculated the standard value of the Laterality Index (LI), which was the MBR comparison of both eyes in each of the regions, in the control subjects. We then investigated the correlation between both eyes for the LIs in the entire fundus, the degree of ICAO and visual function.</p><p>Results</p><p>The disparity of the LIs in both eyes was least in the entire area of the fundus in control subjects and there was a significant correlation between both eyes of the 41 healthy individuals (P = 0.019). Significant correlations were found for the LI, visual acuity and degree of ICAO. The specificity and sensitivity of LI in the entire area was 93.8% and 100%, respectively.</p><p>Conclusions</p><p>LSFG revealed normal individuals have symmetrical fundus blood flow. LSFG could detect OIS and might be a useful tool for detecting disparities in fundus blood flow.</p></div

Case 1. The false color maps of a patient with ocular ischemic syndrome.

<p>Top, right eye; bottom, left eye. Although the color map of the right eye is normal, that of the left eye shows that the choroidal vasculature has disappeared and that there are faint retinal vessels present, suggesting decreased retinal and choroidal blood flows.</p

Absence of astrocyte specificity for the marmoset- and human-derived GFAP promoters in the mouse cerebrum.

<p>(A-C) Cerebral slices lentivirally expressing GFP under the control of the 0.3-kb marmoset-derived cjGFAP (A), 0.3-kb mouse-derived mGFAP (B) or 0.3-kb human-derived hGFAP (C) promoter were triple-immunostained for GFP (green), GFAP (magenta) and NeuN (a neuronal marker, cyan). Note the predominant expression of GFP in neurons (arrow) by the marmoset- and human-derived promoter, which is in sharp contrast to the astrocyte-specific expression (arrowhead) by the mouse-derived promoter. Scale bars, 50 μm. (D) Schema depicting morphology of neuron and astrocyte in the cerebral cortex. (E) Quantitative analysis of the astrocyte specificity for the cjGFAP, mGFAP and hGFAP promoters. More than 300 GFP-positive cells from 3 mice (3 slices/mouse) were randomly selected, and the ratio of GFAP-labeled astrocytes were determined in these random selections. Asterisks indicate statistically significant differences between the mouse promoter and the marmoset or human promoter, as determined by one-way ANOVA followed by Tukey’s post hoc test, ***<i>p</i><0.001.</p

Bilateral comparison of the mean blur ratios in the entire image in normal individuals.

<p>Correlation coefficient of the linear fit r = 0.8594 (P = 0.019).</p

High specificity of the 0.3-kb cjGFAP promoter for astrocytes in the mouse cerebellum.

<p>(A) Shema depicting Purkinje cell (PC) and Bergmann glia (BG) in the cerebellar cortex. Cell bodies of Bergmann glia are present in the Purkinje cell layer (PCL) and extend processes into the molecular layer (ML). GCL; Granule cell layer. (B) A cerebellar section immunolabeled for parvalbumin. Arrows indicate molecular layer interneurons. (C) Cerebellar slices lentivirally expressing GFP under the control of the 1.5 kb mouse GFAP promoter were double-immunostained for GFP and S100 (an astrocyte marker). Arrows and arrowheads indicate cell bodies and the processes of Bergmann glia, respectively. GFP expression was observed in Bergmann glia, but not in Purkinje cells (P). (D-I) Cerebellar slices lentivirally expressing GFP under the control of different lengths of the marmoset GFAP promoter were double-immunostained for GFP and S100. Arrows in (I) indicate GFP-positive interneurons in the molecular layer. Scale bars, 50 μm. (J) Quantitative analysis of astrocyte specificity of the marmoset GFAP promoter fragments. More than 500 GFP-positive cells from 3 mice (3 slices/mouse) were randomly selected in each group, and the ratio of S100-labeled astrocytes was determined in these random selections. Asterisks and daggers indicate statistically significant differences compared with the cerebella expressing GFP under the control of the 2.0-kb promoter (asterisks) or the 0.3-kb promoter (daggers), as determined by one-way ANOVA followed by Tukey’s post hoc test, ***<i>p</i><0.001 and ††<i>p</i><0.01.</p

AAV9 vector-mediated GFP expression in the marmoset brain.

<p>AAV9 vectors expressing GFP under the control of the 0.3-kb cjGFAP promoter were injected into the cerebral and cerebellar cortices. (A and B) Bright field images of the marmoset whole brain overlaid with GFP fluorescence. (C and D) Bright field images of the sagittal sections of the cerebellar (C) and cerebral (D) hemispheres are presented with GFP fluorescence. Scale bars, 2 mm.</p

Patient MBR values for each of the comparison areas.

<p>Patient MBR values for each of the comparison areas.</p

Regions in which the mean blur ratio were measured.

<p>A indicates the retinal artery; B, the retinal vein; C, the temporal sector of the disc; D, the macular area; E, the peripapillary area; and F, the entire image.</p

Summary of MBR values from 41 healthy individuals.

<p>Summary of MBR values from 41 healthy individuals.</p

False color maps of bilateral Laser Speckle Flowgraphy in both eyes of a normal subject.

<p>Top, right eye; bottom, left eye. The right and left differences in the normal subjects was not significant in the blood flow.</p