Relationships among Ocular Blood Flow Shown by Laser Speckle Flowgraphy, Retinal Arteriosclerotic Change, and Chorioretinal Circulation Time Obtained by Fluorescein Angiography

Abstract

Purpose. To determine the correlations among the mean blur rate (MBR) in the optic nerve head (ONH) shown by laser speckle flowgraphy (LSFG), retinal arteriosclerosis, and the circulation time obtained by fluorescein angiography (FA). Method. We evaluated 118 patients and assessed their time of choroidal flush, arm-to-retina time, and early and late phases of retinal circulation time (RT: sec) obtained by FA. The severity of retinal arteriosclerosis was classified according to the Scheie classification. The MBR values throughout the ONH (MBR-A), in the tissue (MBR-T), and in the vessels (MBR-V) were analyzed. Results. Patients with retinal vein occlusion (RVO) showed prolonged early and late phases of RT compared to other ocular diseases. Single and multiple regression analyses showed that the MBR-V and Scheie classification were significantly associated with both the choroidal flush and arm-to-retina times. The incidences of RVO and MVR-V were significantly associated with the early phase of RT, and the incidences of RVO, MBR-V, Scheie classification, and gender were revealed to be factors independently contributing to the late phase of RT. Conclusion. MBR-V in the ONH and retinal arteriosclerosis are important contributing factors for the circulation time of each stage obtained by FA.

Relative Retinal Blood Flow: A Novel and Informative Measure of Unilateral Retinal Vein Occlusion Severity

“…In RVO eyes, there is a significant association between vascular MBR and early-and late-phase fluorescein angiography circulation times. 4 Similarly, two studies found a significantly lower blood flow in the ONH in ischemic RVO compared to nonischemic RVO, matching our understanding of severe perfusion deficits in eyes with ischemic RVOs. 24,25 LSFG findings also match our understanding of retinal autoregulation, because pure oxygen inhalation significantly decreases ONH MBR in healthy eyes.…”

“…Recently, imaging techniques such as laser speckle flowgraphy (LSFG) and OCT angiography (OCTA) have emerged as more-precise and lessinvasive ways of determining changes in retinal blood flow. 4,5 LSFG, approved by the Food and Drug Administration in 2016, is a relatively new, noninvasive technology for measuring retinal blood flow. [6][7][8][9] Although other imaging techniques exist, such as blue-field simulation, spectral-domain OCT, laser Doppler flowmetry, laser Doppler velocimetry, Doppler Fourier-domain OCT, and swept source OCT, LSFG is unique in that it is a noninvasive technique that allows for quantitative, dynamic imaging of blood flow through retinal vessels and the choroid in the optic nerve head (ONH) and macula.…”

“…5 LSFG metrics correspond well with our current understanding of retinal blood flow, both in patients with RVO and healthy subjects. 4,23 Mean blur rate (MBR), a quantitative measure of erythrocyte movement based on laser speckle patterns, is the main output of LSFG, and most studies use MBR or a ratio of MBR as a direct correlate of blood flow. In RVO eyes, there is a significant association between vascular MBR and early-and late-phase fluorescein angiography circulation times.…”

Hallucal thenar index: A new index to detect peripheral arterial disease using laser speckle flowgraphy

“…Ophthalmologists previously reported evaluation of ocular blood flow with LSFG, 9–12 and one vascular surgeon reported determination of leg blood flow using this method. 6 All of these studies used the value itself; the former used the MBR only to monitor individual changes, while the latter used BSSP itself to distinguish between non-PAD controls and PAD patients.…”

“…Laser speckle flowgraphy (LSFG) can be used to determine cutaneous blood flow without making contact with the skin. 6–8 There have been several reports of the evaluation of ocular blood flow with LSFG, 9–13 but there has been only one report of the use of this method to determine cutaneous blood flow in the leg. 6…”