Effects of Trabeculectomy on Waveform Changes of Laser Speckle Flowgraphy in Open Angle Glaucoma

Takeshima, Satoshi; Higashide, Tomomi; Kimura, Masayo; Udagawa, Sachiko; Yamada, Yutaro; Takemoto, Daisuke; Ohkubo, Shinji; Sugiyama, Kazuhisa

doi:10.1167/iovs.18-25694

Cited by 17 publications

(33 citation statements)

References 32 publications

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“…In 48 eyes with open-angle glaucoma, Takeshima et al13 found that BOS increased and RI decreased following trabeculectomy, with no accompanying change in average MBR. Similarly, in our study, as seen in Table 2, BOS was significantly higher in normal control eyes than in the P3 eyes without functional loss, with P = 0.039, while RI was lower in the normal control eyes, although with P = 0.058.…”

Section: Discussionmentioning

confidence: 99%

“…As such, it is able to parameterize and hence quantify aspects of the pulsatile waveform, potentially revealing insights into pathophysiological changes in the response across the cardiac cycle. Though the physiological specifications of these parameters have not been systemically investigated, multiple studies have shown they can be used to reveal hemodynamic differences in glaucoma 10,13–15. This suggests that LSFG may provide a way to assess and quantify changes in both ONH blood flow and its pulsatile variation in vivo in human glaucoma.…”

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confidence: 99%

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Increased Optic Nerve Head Capillary Blood Flow in Early Primary Open-Angle Glaucoma

Gardiner

Cull

Fortune

et al. 2019

Invest. Ophthalmol. Vis. Sci.

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PURPOSE. Blood flow in the optic nerve head (ONH) is known to be reduced in eyes with advanced glaucoma. However, experimental results from non-human primates suggest an initial increase in ONH blood flow at the earliest stages of damage. This study assesses flow and pulsatile hemodynamics across a range of severities to test the hypothesis that this also occurs in human glaucoma. METHODS. Laser speckle flowgraphy was used to measure average mean blur rate (MBR ave) within ONH tissue (a correlate of capillary blood flow) and the pulsatile waveform in 93 eyes with functional loss and 74 glaucoma suspect/fellow eyes without functional loss. These were compared against results from 92 healthy control eyes. Parameters produced by the instrument's software were age-corrected, then compared between groups using generalized estimating equation models. RESULTS. The mean MBR ave in the control eyes was 12.5 units. In glaucoma suspect/fellow eyes, the mean was 16.4 units, higher with P < 0.0001. In eyes with functional loss, the mean was 13.8 units, lower than eyes without functional loss with P < 0.0001, although still higher than control eyes with P ¼ 0.0096. Analysis of the pulsatile waveform suggested that the deceleration in flow as it approaches its maximum across the cardiac cycle was delayed in glaucoma. CONCLUSIONS. Blood flow within ONH capillaries was higher in glaucoma suspect eyes than in healthy controls. It was less elevated in eyes that had developed functional loss. The mechanisms causing these changes and their relation to concurrent changes in pulsatile hemodynamics remain under investigation.

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Section: Discussionmentioning

confidence: 99%

mentioning

confidence: 99%

Increased Optic Nerve Head Capillary Blood Flow in Early Primary Open-Angle Glaucoma

Gardiner

Cull

Fortune

et al. 2019

Invest. Ophthalmol. Vis. Sci.

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“…RI demonstrated a significant decrease over time in all regions. An open-angle glaucoma study, in a young age group reported that, BOS increased with a decrease in RI, suggesting maintenance of stable blood flow 25 . As shown by the waveform area illustrated in Fig.…”

Section: Discussionmentioning

confidence: 94%

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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“…The MBR images of the ONH were recorded at a rate of 30 frames/s over a 4 s period and automatically detected the beginning and the end of the heartbeat recorded within 4 s. The total number of frames was 118 (Figure 1(b)). Images corresponding to the identical phases within 1 heartbeat duration were synthesized to one image sequence [27]. The averaged MBR for a heartbeat was calculated and displayed as a heartbeat map (Figure 1(c)).…”

Section: Methodsmentioning

confidence: 99%

“…Another study showed that the skew and blowout time (BOT) correlated with the mean deviation (MD) in patients with primary open-angle glaucoma (POAG) [26]. However, to the best of our knowledge, only one trabeculectomy study [27] has performed pulse waveform analysis of ocular blood flow before and after glaucoma treatment. The purpose of the present study was to evaluate the effect of PG analog instillation or trabeculectomy on the pulse waveforms for ONH microcirculation using LSFG.…”

Section: Introductionmentioning

confidence: 99%

Pulse Waveform Analysis of the Ocular Blood Flow Using Laser Speckle Flowgraphy before and after Glaucoma Treatment

Masai

Ishida

Anraku

et al. 2019

Journal of Ophthalmology

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Although reduction in intraocular pressure (IOP) is the principle of glaucoma treatment, impaired ocular blood flow is believed to play a role in the progression of glaucoma. This study evaluated the effect of glaucoma treatment on pulse waveforms for optic nerve head (ONH) microcirculation in patients with glaucoma. Fifty-one subjects were included on the basis of the glaucoma treatment administered, which involved instillation of prostaglandin (PG) analogs (PG group; n = 28) or trabeculectomy (trabeculectomy group; n = 23). ONH blood flow, represented by the mean blur rate (MBRT) and pulse waveforms, was measured using laser speckle flowgraphy before and 1 and 3 months after treatment. Three months after treatment, IOP exhibited a significant decrease (p < 0.05). Although there was no significant change in MBRT after treatment, the acceleration time index (ATI) significantly decreased (p=0.034) in the PG group. In the trabeculectomy group, there was no significant change in the MBRT after treatment, while fluctuation (p=0.019) and blowout score (BOS) (p=0.036) exhibited significant decrease and increase, respectively. Multiple regression analysis showed that mean deviation was significantly associated with the rate of change in the BOS (p=0.013), age was a significant contributing factor for the rate of change in fluctuation in the trabeculectomy group, reflection was significantly associated with the ATI (p=0.037) in the in the PG group. Both glaucoma treatments can change the pulse waveforms, with MBRT remaining unchanged, and IOP reduction owing to the treatment may contribute to stable blood flow in the tissue area of the ONH. As impaired ocular blood flow plays a role in the progression of glaucomatous damage, it would be beneficial if glaucoma treatment could improve the stability of ONH microcirculation.

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Effects of Trabeculectomy on Waveform Changes of Laser Speckle Flowgraphy in Open Angle Glaucoma

Cited by 17 publications

References 32 publications

Increased Optic Nerve Head Capillary Blood Flow in Early Primary Open-Angle Glaucoma

Increased Optic Nerve Head Capillary Blood Flow in Early Primary Open-Angle Glaucoma

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

Pulse Waveform Analysis of the Ocular Blood Flow Using Laser Speckle Flowgraphy before and after Glaucoma Treatment

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