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

Shinohara, Yusuke; Kashima, Tomoyuki; Akiyama, Hideo; Shimoda, Yoko; Li, Danjie; Kishi, Shoji

doi:10.1371/journal.pone.0169596

Cited by 12 publications

(13 citation statements)

References 24 publications

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“…Additionally, the degree of ICA stenosis was 76 %. This finding is similar to that from a previous study in which the degree of the ICA stenosis and the ratio of the affected to the fellow eye was shown to be inversely correlated [17]. In the present case we found a higher level of HbA1c and IOP (50mmHg) caused by rubeosis iridis.…”

Section: Discussionsupporting

confidence: 93%

“…The previous study that used LSFG demonstrated that MBR in the ONH and choroid in the affected eye significantly decreased compared with that in the fellow eye in OIS [17]. However, to the best of our knowledge, the time course of the optic nerve head, choroidal blood flow, and pulse waveform using LSFG in OIS with rubeosis iridis is yet to be investigated.…”

Section: Introductionmentioning

confidence: 90%

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Time Course in Ocular Blood Flow and Pulse Waveform in a Case of Ocular Ischemic Syndrome with Intraocular Pressure Fluctuation

Yamazaki

Hashimoto

Masahara

et al. 2020

Vision

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We report on a 70-year-old Japanese man with complaints of worsening left visual acuity who was diagnosed with ocular ischemic syndrome (OIS) associated with internal carotid artery (ICA) stenosis. A gonioscopy examination showed rubeosis iridis and elevated intraocular pressure (IOP) in the left eye (50 mmHg) at the baseline visit. The optic nerve head (ONH) and choroidal blood flow measured by laser speckle flowgraphy (LSFG) was impaired in the left eye compared with that in the right eye. Additionally, the blowout score (BOS), which indicates the variation of the mean blur rate (MBR) during systolic and diastolic periods, was decreased in the left eye. After treatment with an injection of bevacizumab and administration of Rho-associated kinase-inhibitor ripasudil eye drops, both ocular blood flow and BOS in each vascular bed gradually increased along with IOP reduction. The visual acuity also improved. The current case demonstrated increased blood flow and decreased fluctuation of blood flow in the ONH and choroid before and after the treatment in OIS with rubeosis iridis. The LSFG technique is useful to non-invasively assess the ocular circulation and pulse waveform in OIS.

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Section: Discussionsupporting

confidence: 93%

Section: Introductionmentioning

confidence: 90%

Time Course in Ocular Blood Flow and Pulse Waveform in a Case of Ocular Ischemic Syndrome with Intraocular Pressure Fluctuation

Yamazaki

Hashimoto

Masahara

et al. 2020

Vision

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“…In our study, we showed that the normal non-anesthetized eyes of rabbits depict a strong correlation with their fellow eyes. A similar study demonstrated a significant correlation of blood flow volume in the normal eyes of healthy human subjects 15 . They found the LI for the entire image to be equivalent to one.…”

Section: Discussionmentioning

confidence: 56%

“…Similarly, Shinohara et al . defined the LI as a ratio of the MBR value of the occluded eye to that of the non-occluded eye to diagnose patients with OIS 15 . In this study, we defined the LI as a ratio of the lower MBR value to the higher MBR value for normal eyes.…”

Section: Resultsmentioning

confidence: 99%

Ocular Blood Flow in Rabbits under Deep Anesthesia: A Real-Time Measurement Technique and Its Application in Characterizing Retinal Ischemia

Bhatti

Tang

Chen

2018

Sci Rep

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In this study, we reported a new technique based on laser speckle flowgraphy to record the ocular blood flow in rabbits under deep anesthesia, and proposed parameters to characterize retinal ischemia. We applied the proposed technique to study the correlation of blood flow between the eyes of normal non-anesthetized animals, and to characterize the occlusion of the internal carotid artery (ICA) and external carotid artery (ECA). We established a correlation in blood flow between the eyes of non-anesthetized animals, and derived two new parameters, namely, the laterality index and vascular perfusion estimate (VPE). Our experimental results from 16 eyes (of 13 New Zealand white rabbits) showed a reduction in ocular blood flow with a significant decrease in the VPE after the occlusion of the ECA (p < 0.001). A low/minimal effect on blood flow was observed with the occlusion of the ICA. In conclusion, we demonstrated a means for the real-time measurement of the ocular blood flow in rabbits under deep anesthesia by using laser speckle flowgraphy and the VPE as an indicator of successful occlusion. The proposed technique might be applicable in quantifying the efficacy of new drugs and interventions for the treatment of retinal ischemia.

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“…Furthermore, associated diseases such as hypertension and diabetes also contribute to the vessel elasticity impairment 11 . Several studies have reported that carotid artery stenosis due to atherosclerosis results in impaired OBF as measured by using the MBR 12,13 . However, the characteristics of ocular hemodynamic remain unknown.…”

mentioning

confidence: 99%

Longitudinal effects of common carotid artery stenosis on ocular hemodynamics assessed using laser speckle flowgraphy in a rabbit model

Ismail

Chen

Faye

et al. 2020

Sci Rep

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Real-time impairment of ocular blood flow (OBF) under common carotid artery stenosis (CCAS) has not been ascertained. We aimed to longitudinally assess the impact of CCAS on OBF using a rabbit model. About 75% stenosis was created by tying the common carotid artery with a plastic mandrel using a nylon suture. The plastic mandrel was gently removed, leaving a ligature. Neurological and behavioral assessments were recorded as the clinical indicator of stroke severity. With laser speckle flowgraphy, the pulse waveform parameters namely mean blur rate (MBR), blowout score (BOS), blowout time (BOT), rising rate, S1-area, falling rate (FR), S2-area, flow acceleration index (FAI), acceleration time index, resistive index (RI) and the difference between the maximum and minimum values of MBR (AC) were assessed in overall, vessel, and tissue regions of the optic nerve head (ONH). Longitudinally, BOS significantly increased until day 19 post-surgery, whereas FAI, RI, and AC significantly decreased. Beyond day 19, BOS, BOT, FR, FAI, RI, and AC significantly decreased. We defined two stages representing impaired vessel conditions, namely the vessel resistance phase, where BOS increases and FAI, RI, and AC decrease, and the vessel elasticity phase where BOS, BOT, FR, FAI, RI and AC decrease. These stages provide information about atherosclerosis, assessable non-invasively through the eye.

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

Cited by 12 publications

References 24 publications

Time Course in Ocular Blood Flow and Pulse Waveform in a Case of Ocular Ischemic Syndrome with Intraocular Pressure Fluctuation

Time Course in Ocular Blood Flow and Pulse Waveform in a Case of Ocular Ischemic Syndrome with Intraocular Pressure Fluctuation

Ocular Blood Flow in Rabbits under Deep Anesthesia: A Real-Time Measurement Technique and Its Application in Characterizing Retinal Ischemia

Longitudinal effects of common carotid artery stenosis on ocular hemodynamics assessed using laser speckle flowgraphy in a rabbit model

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