Assessment of choroidal blood flow using laser speckle flowgraphy

Calzetti, Giacomo; Fondi, Klemens; Bata, Ahmed M.; Luft, Nikolaus; Woźniak, Piotr A.; Witkowska, K.; Bolz, Matthias; Popa-Cherecheanu, Alina; Werkmeister, René M.; Schmidl, Doreen; Garhöfer, Gerhard; Schmetterer, Leopold

doi:10.1136/bjophthalmol-2017-311750

Cited by 35 publications

(41 citation statements)

References 36 publications

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“…OCT based methods have been used with the purpose of imaging the choroid en-face [11][12][13][14] but the technique faces issues including fringe washout due to the large choroidal blood flow and recent work suggests that a higher acquisition rate improves the quality of choroidal images [15]. Laser speckle flowgraphy also allows en-face imaging of the choroid but details of choroidal vessels are rather limited [16,17]. Ultimately, none of the above-mentioned techniques allows a robust arteriovenous differentiation and quantitative flow measurements.…”

Section: Introductionmentioning

confidence: 99%

Choroidal vasculature imaging with laser Doppler holography

Puyo¹,

Pâques²,

Fink³

et al. 2019

Biomed. Opt. Express

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The choroid is a highly vascularized tissue supplying the retinal pigment epithelium and photoreceptors. Its implication in retinal diseases is gaining increasing interest. However, investigating the anatomy and flow of the choroid remains challenging. Here we show that laser Doppler holography provides high-contrast imaging of choroidal vessels in humans, with a spatial resolution comparable to state-of-the-art indocyanine green angiography and optical coherence tomography. Additionally, laser Doppler holography contributes to sort out choroidal arteries and veins by using a power Doppler spectral analysis. We thus demonstrate the potential of laser Doppler holography to improve our understanding of the anatomy and flow of the choroidal vascular network.

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Section: Introductionmentioning

confidence: 99%

Choroidal vasculature imaging with laser Doppler holography

Puyo¹,

Pâques²,

Fink³

et al. 2019

Biomed. Opt. Express

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“…Laser Doppler flowmetry [3] and laser speckle flowgraphy have been used to quantify microvascular flow [4], but measurements are limited to the fovea because the inner retina is avascular in this region. Laser speckle flowgraphy has also been used to study flow in larger choroidal vessels [5] and color Doppler imaging allows for the measurement of blood velocities in the posterior ciliary arteries that supply the choroid [6], but these approaches provide limited lateral resolution. More recently optical coherence tomography angiography (OCTA) [7][8][9] was introduced to image the choroid providing volumetric information on the microvasculature, but quantification is still challenging.…”

Section: Introductionmentioning

confidence: 99%

Quantitative analysis of choriocapillaris in non-human primates using swept-source optical coherence tomography angiography (SS-OCTA)

Tan¹,

Chua²,

Barathi³

et al. 2018

Biomed. Opt. Express

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The choriocapillaris is a unique vascular plexus located posterior to the retinal pigment epithelium. In recent years, there is an increasing interest in the examination of the interrelationship between the choriocapillaris and eye diseases. We used several techniques to study choroidal perfusion, including laser Doppler flowmetry, laser speckle flowgraphy, and optical coherence tomography angiography (OCTA), but with the latter no standardized algorithm for quantitative analysis has been provided. We analyzed different algorithms to quantify flow voids in non-human primates that can be easily implemented into clinical research. In-vivo, high-resolution images of the non-human primate choriocapillaris were acquired with a swept-source OCTA (SS-OCTA) system with 100kHz A-scan/s rate, over regions of 3 × 3 mm 2 and 12 × 12 mm 2. The areas of non-perfusion, also called flow voids, were segmented with a structural, intensity adjusted, uneven illuminance-compensated algorithm and the new technique was compared to previously published methods. The new algorithm shows improved reproducibility and may have applications in a wide array of eye diseases including age-related macular degeneration (AMD).

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“…Validation of this approach for the measurement of perfusion in larger choroidal vessels was established by means of comparison with laser Doppler flowmetry in healthy subjects. 25 Measurement of feeder vessel perfusion might be of value in patients with nAMD, but again needs to be studied in a larger population.…”

Section: Discussionmentioning

confidence: 99%

“…1). 25 Briefly, the signal from this ROI contains information from the blood stream within the vessel as well as from the superimposed microvasculature. The signal from the larger vessel is automatically separated from MBR originating from the surrounding microvasculature by computing a threshold between MBR value.…”

Section: Cnv Analysismentioning

confidence: 99%

Assessment of Choroidal Neovascularization Perfusion: A Pilot Study With Laser Speckle Flowgraphy

Calzetti

Mora

Favilla³

et al. 2020

Trans. Vis. Sci. Tech.

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The purpose of this study was to quantify perfusion in the area of choroidal neovascularization (CNV) using laser speckle flowgraphy (LSFG) before and after intravitreal anti-vascular endothelial growth factor (VEGF) injection. Methods: Retrospective case series. Fifteen eyes of 15 patients with treatment-naïve CNV due to age-related macular degeneration (AMD) and with available LSFG images were included. The main outcome was the mean blur rate (MBR) quantified as a measure of perfusion within the CNV area observed on indocyanine green angiography. Twelve patients had available longitudinal data until one month after the injection, used to evaluate changes in perfusion, central macular thickness (CMT), visual acuity, and ocular perfusion pressure. Reproducibility of LSFG measurements was investigated at each time point from two images taken within five minutes. Results: Intraclass correlation coefficients for LSFG measurements were higher than 0.8 indicating excellent reproducibility. There was a significant decrease in perfusion after one week (-26.4 ± 14.4%; P = 0.027), whereas, after one month, perfusion was no longer significantly different from baseline (P = 0.121). CMT showed a progressive decrease over the follow-up period. Changes in perfusion were strongly correlated with changes in CMT after one week, but not thereafter. Conclusions: This pilot study suggests a method to select a region in the CNV area to quantify perfusion using LSFG. MBR could represent a parameter possibly related to regrowth of the CNV after anti-VEGF treatment. Large-scale studies are needed to assess the usefulness of LSFG in defining re-treatment criteria for neovascular AMD. Translational Relevance: LSFG technology to quantify perfusion could provide useful biomarkers for therapeutic management of CNV.

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Assessment of choroidal blood flow using laser speckle flowgraphy

Abstract: NCT02102880, Results.

Cited by 35 publications

References 36 publications

Choroidal vasculature imaging with laser Doppler holography

Choroidal vasculature imaging with laser Doppler holography

Quantitative analysis of choriocapillaris in non-human primates using swept-source optical coherence tomography angiography (SS-OCTA)

Assessment of Choroidal Neovascularization Perfusion: A Pilot Study With Laser Speckle Flowgraphy

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