Leakage is caused by neovascularization, and since peripheral blood flow is low in such areas, LSFG shows low values.
On the other hand, when leakage is detected by FA (fluorescein angiography) or similar methods, it appears as fluorescent spots; however, since blood flow is low in those areas, LSFG depicts them as low values.
If the area surrounding the leakage site also has low blood flow, the leakage site will only show a distribution of low values on LSFG, making it impossible to confirm the presence of leakage.
Dr. Watanabe of Gunma University has published well-organized papers on this topic, which we introduce as references for your review.

Watanabe G, Fujii H, Kishi S: Imaging of Choroidal Hemodynamics in Eyes with Polypoidal Choroidal Vasculopathy Using Laser Speckle Phenomenon Jpn J Ophthalmol 52: 204-210, 2008

It is not possible to compare multiple files within a single analysis software instance, but it is possible to launch multiple instances of the analysis software.
Depending on the performance of the computer, three or four instances can be launched without any issues on the computers we have installed.
If multiple analysis software instances are running, the measurement software may not be able to start, so please do not launch multiple analysis software instances during measurement.

LSFG FAQ

References

Topics

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Advancing fundus blood flow science

The fundus is the only place
in the body where blood vessels
can be observed directly.

Measuring not just blood flow volume, but its waveform — the quality of flow — to capture the earliest signals of vascular change. That is what LSFG makes possible.

Certified in Japan since 2008 FDA-cleared 510(k) 2016 600+ peer-reviewed publications 90+ research institutions

Softcare is the company that first commercialized LSFG technology as a certified medical device, and continues to advance it.

01 — What is blood flow?

Blood flow is the foundation of life.

Every cell in the human body depends on blood flow to receive oxygen and nutrients, and to remove metabolic waste. From the heart to the brain, to the eye, to the fingertips — blood flow sustains every organ, every moment.

01

The body's invisible infrastructure

Like the roads, water, and electricity of a city, blood flow operates silently in the background — essential, yet rarely noticed until something goes wrong.

02

Reaches every corner of the body

Oxygen and nutrients are delivered to every cell; metabolic waste is carried away. This continuous exchange is what keeps every organ functioning.

03

Change begins before symptoms appear

Just as infrastructure degrades quietly before it fails, blood flow can change long before structural damage or clinical symptoms become visible.

02 — Why does blood flow matter?

When blood flow falters,
the body suffers.

Impaired blood flow underlies many of the most serious diseases known to medicine. What these conditions share is a common origin: disruption of blood flow at the microvascular level.

Glaucoma

Reduced optic nerve head perfusion is implicated in the progression of glaucomatous damage, often preceding detectable visual field loss.

Diabetes & Metabolic Disease

Microvascular dysfunction is a hallmark of diabetic complications, affecting the fundus, kidneys, and peripheral circulation.

Cardiovascular Disease

Fundus(Retina and Choroid) blood flow waveform parameters have been shown to correlate with systemic arteriosclerosis markers including baPWV and carotid IMT.

Neurological Conditions

Cerebrovascular changes and neurodegenerative processes have been linked to alterations in fundus microcirculation.

Critically, changes in blood flow often precede structural damage. Observing blood flow continuously offers a window into the earliest stages of disease — before irreversible harm has occurred.

03 — Why waveform? Why the retina?

Flow volume tells you something.
Flow waveform tells you more.

The dynamic pattern of each cardiac cycle — systolic peaks, diastolic troughs, pulsatility indices — carries far richer data about the true condition of the microvasculature than volume alone.

Conventional assessment

Blood flow "volume"

Average velocity or perfusion volume. Tells you whether flow is high or low — but cannot reveal the dynamic behaviour of the vasculature.

LSFG assessment
Blood flow "waveform"

          Beat-by-beat waveform acquisition. Systolic peak, diastolic trough,
          pulsatility index, waveform asymmetry — multi-dimensional vascular dynamics.
        
          0s
          2s
          4s

And where is the ideal site to observe this waveform?
The Fundus (Retina and Choroid).

The fundus is the only tissue in the human body where blood vessels can be observed directly, low-invasively, and in real time. Fundus microcirculation reflects the systemic microvascular environment — making the fundus a uniquely privileged window into the body's vascular health.

04 — LSFG technology

From research
to clinical practice.

Softcare is the company that first commercialized LSFG technology as a certified medical device, and continues to advance it.

Low-invasive, 4 seconds per shot

Real-time 2D blood flow mapping

Various quantitative waveform parameters

Medical device model: LSFG-NAVI

Research models: LSFG-LITE / LSFG-Micro for animal experiments

600+

Peer-reviewed
publications

90+

Research institutions
worldwide

2008

First certified
in Japan

2016

FDA-cleared
510(k)

Learn more about our products →

LSFG-NAVI medical device

05 — Research applications

From the fundus,
a window into systemic vascular health.

LSFG technology has been utilized in a broad and growing range of research fields, reflecting the fundus's unique position as a direct and low-invasive observation point for microvascular physiology.

Ophthalmology — Glaucoma

Waveform analysis in glaucomatous damage

Waveform analysis of optic nerve head blood flow has been used to study microcirculatory changes associated with glaucomatous damage and the effects of surgical intervention.

Shiga Y et al. IOVS, 2013

Takeshima S et al. IOVS, 2019

Ophthalmology — Diabetic Retinopathy

Fundus microcirculation in diabetes

Fundus microcirculation observed by LSFG has been studied in relation to systemic vascular changes in diabetic patients, including correlations with carotid artery resistance.

Sawada S et al. Diabetes Res Clin Pract, 2020

Hanaguri J et al. Sci Rep, 2021

Ophthalmology — Retinal Vascular Occlusion

Microvascular resistance in vein occlusion

Waveform-based assessment of retinal microvascular resistance has been investigated in central and branch retinal vein occlusion, including its potential as a predictor of macular edema recurrence.

Matsumoto M et al. TVST, 2020

Hashimoto R et al. Diagnostics, 2024

Ophthalmology — Choroidal Circulation

Choroidal blood flow beyond ocular disease

Choroidal blood flow waveforms have been studied in chorioretinal diseases as well as systemic conditions such as pregnancy-induced hypertension, demonstrating the breadth of LSFG applications.

Saito M et al. IOVS, 2015

Yata K, Hashimoto R et al. AJO Case Rep, 2020

Cardiovascular Medicine

Systemic arteriosclerosis correlations

Correlations between fundus blood flow waveform parameters and systemic arteriosclerosis markers, including baPWV and carotid IMT, have been reported from multiple institutions.

Shiba T et al. Graefe's Archive, 2012

Ebuchi Y, Nagaoka T et al. Sci Rep, 2022

Neurology / Neurosurgery

Cerebrovascular monitoring

Fundus blood flow changes during carotid endarterectomy and correlations with cerebrovascular conditions have been investigated at multiple centres.

Motoyama Y et al. J Clin Monit Comput, 2020

Yoshida S et al. Acta Neurochir, 2020

Metabolic Disease

Microcirculation in systemic metabolic conditions

Studies have examined fundus microcirculation in patients with diabetes, chronic kidney disease, and metabolic syndrome across multiple institutions.

Shiba T et al. J Diabetes Res, 2017

Iwase T et al. Life, 2023

Sports Science / Preventive Medicine / Aging

Microvascular aging and exercise physiology

Fundus blood flow waveform data have been used to study physiological responses to exercise and to estimate microvascular aging using machine learning, with implications for health promotion research.

Magi S, Maruyama T et al. Sci Rep, 2026

Ikemura T, Hayashi N. Eur J Appl Physiol, 2012

Blood flow assessment holds the potential to inspire entirely new research themes — from the elucidation of disease mechanisms to a deeper understanding of human health. We look forward to the discoveries that lie ahead, together with researchers worldwide.

Blood vessels are working quietly, right now.
Our mission: to bring the technology that listens
to their voice — to the world.

Softcare Co., Ltd.