Intrasession repeatability and intersession reproducibility of peripapillary OCTA vessel parameters in non-glaucomatous and glaucomatous eyes

ObjectiveTo compare intrasession repeatability versus intersession reproducibility of the peripapillary vessel parameters using optical microangiography–based optical coherence tomography angiography (OCTA) in non-glaucomatous and glaucomatous eyes.MethodsIn an observational, longitudinal study, peripapillary OCTA scans were collected to evaluate intrasession repeatability and intersession reproducibility using within-eye coefficient of variation (CVW) and intraclass correlation coefficient (ICC). Images were quantified using a custom research–oriented quantification software calculating vessel area density (VAD) and flux and a commercially developed, clinic-oriented quantification software (Cirrus 11.0, Carl Zeiss Meditec) calculating perfusion density (PD) and flux index (FI). Effect of signal strength on the reliability of OCTA parameters was also evaluated.ResultsAmong 120 non-glaucomatous eyes, intrasession CVW were 4.2% for VAD, 5.3% for flux, 1.5% for PD and 2.0% for FI. The intersession CVW were 6.5% for VAD, 8.0% for flux, 2.0% for PD and 3.2% for FI. The intrasession ICC ranged from 0.928 to 0.945, and intersession ICC ranged from 0.811 to 0.866. From 118 glaucomatous eyes, intrasession CVW was 9.0% for VAD, 10.3% for flux, 1.7% for PD and 2.3% for FI. The intersession CVW was 12.1% for VAD, 14.2% for flux, 2.3% for PD and 3.5% for FI. The intrasession ICC ranged from 0.904 to 0.972, and intersession ICC ranged from 0.855 to 0.955. Signal strength was significantly positively associated with OCTA vessel parameters (p<0.0001) for both groups.ConclusionPeripapillary OCTA vessel parameters had greater intrasession repeatability compared to intersession reproducibility in both non-glaucomatous and glaucomatous eyes. The built-in commercially developed quantification software demonstrated greater agreement than the custom research–oriented quantification software.

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Repeatability of Peripapillary Optical Coherence Tomography Angiography Parameters in Older Adults

Journal of VitreoRetinal Diseases ◽

10.1177/2474126420953968 ◽

2020 ◽

pp. 247412642095396

Author(s):

Cason B. Robbins ◽

Dilraj S. Grewal ◽

Atalie C. Thompson ◽

Stephen P. Yoon ◽

Brenda L. Plassman ◽

...

Keyword(s):

Older Adults ◽

Optical Coherence Tomography ◽

Optical Coherence Tomography Angiography ◽

Intraclass Correlation ◽

Cross Sectional Study ◽

Optical Coherence ◽

Capillary Perfusion ◽

Cross Sectional ◽

Capillary Plexus ◽

Perfusion Density

Purpose: This work assesses the intrasession repeatability of capillary perfusion density (CPD) and capillary flux index (CFI) measurements on peripapillary optical coherence tomography angiography (OCTA) in healthy eyes of older adults. Methods: In this cross-sectional study, healthy volunteers aged 50 years or older underwent 4.5 × 4.5 mm OCTA imaging centered on the optic nerve head using Zeiss Cirrus HD-5000 AngioPlex (Carl Zeiss Meditec). Two consecutive images were acquired in the same eye during a single study session. CPD and CFI were assessed using AngioPlex Software (version 11.0.0.29946) for the radial peripapillary capillary plexus (average over whole scan area) and 4 quadrants (superior, inferior, temporal, and nasal). CPD and CFI repeatability was assessed by intraclass correlation (ICC), mean interocular differences using 2-tailed t test, and association with age using generalized estimating equations. Results: A total of 150 images were acquired from 75 eyes of 47 patients. For CPD, ICC results ranged from 0.7160 (nasal CPD) to 0.9218 (average CPD). For CFI, ICC results ranged from 0.6167 (temporal CFI) to 0.8976 (inferior CFI). Temporal CFI was significantly different between right and left eyes of the same patient ( P = .03). CPD and CFI decreased with age in all analyses (average CPD β coefficient –0.00172, P < .001; average CFI β coefficient −0.00278, P < .001). Conclusions: Moderate to good repeatability was observed for most peripapillary OCTA metrics; temporal measurements were least repeatable for CPD and CFI. Peripapillary CPD and CFI decrease with age even beyond the fifth decade in healthy older adults.

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Signal Strength as an Important Factor in the Analysis of Peripapillary Microvascular Density Using Optical Coherence Tomography Angiography

Scientific Reports ◽

10.1038/s41598-019-52818-x ◽

2019 ◽

Vol 9 (1) ◽

Cited By ~ 3

Author(s):

Hyung Bin Lim ◽

Yong Woo Kim ◽

Ki Yup Nam ◽

Cheon Kuk Ryu ◽

Young Joon Jo ◽

...

Keyword(s):

Optical Coherence Tomography ◽

Optical Coherence Tomography Angiography ◽

Structural Parameters ◽

Signal Strength ◽

Microvascular Density ◽

Optical Coherence ◽

Regression Analyses ◽

Fiber Layer ◽

Nerve Fiber Layer Thickness ◽

Perfusion Density

Abstract The quality of the scan image is important in peripapillary circulation analysis using optical coherence tomography angiography (OCTA). We aimed to investigate the effects of signal strength (SS) on the peripapillary microvascular density acquired from OCTA. A total of 259 eyes from 259 young healthy subjects were included. Peripapillary OCTA images using 3 × 3 mm angiography scan were acquired from all participants. Subjects were divided into four groups according to the SS: SS 7, SS 8, SS 9, and SS 10. Vessel density (VD) and perfusion density (PD) of the superficial capillary plexus were calculated. VD and PD were compared among the four groups, and linear regression analyses were performed to identify and evaluate the clinical factors associated with average VD. As the SS increased from 7 to 10, the average VD and PD increased; these increases were statistically significant (all, p < 0.001). Regression analyses showed that four factors were significantly correlated with average VD: age (partial r = 0.133), average retinal nerve fiber layer thickness (partial r = 0.169), cup/disc ratio (partial r =−0.481), and SS (partial r = 0.413). SS is a significant factor affecting peripapillary microvascular density, and its influence is similar to well-known structural parameters associated with glaucoma.

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Repeatability, interocular correlation and agreement of quantitative swept-source optical coherence tomography angiography macular metrics in healthy subjects

British Journal of Ophthalmology ◽

10.1136/bjophthalmol-2018-311874 ◽

2018 ◽

Vol 103 (3) ◽

pp. 415-420 ◽

Cited By ~ 23

Author(s):

Danqi Fang ◽

Fang Yao Tang ◽

Haifan Huang ◽

Carol Y Cheung ◽

Haoyu Chen

Keyword(s):

Optical Coherence Tomography ◽

Fractal Dimension ◽

Correlation Coefficient ◽

Healthy Subjects ◽

Optical Coherence Tomography Angiography ◽

Intraclass Correlation ◽

Vessel Density ◽

Optical Coherence ◽

Swept Source ◽

Significant Difference

PurposeTo investigate the repeatability, interocular correlation and agreement of quantitative swept-source optical coherence tomography angiography (SS-OCTA) metrics in healthy subjects.MethodsThirty-three healthy normal subjects were enrolled. The macula was scanned four times by an SS-OCTA system using the 3 mm×3 mm mode. The superficial capillary map images were analysed using a MATLAB program. A series of parameters were measured: foveal avascular zone (FAZ) area, FAZ perimeter, FAZ circularity, parafoveal vessel density, fractal dimension and vessel diameter index (VDI). The repeatability of four scans was determined by intraclass correlation coefficient (ICC). Then the averaged results were analysed for intereye difference, correlation and agreement using paired t-test, Pearson’s correlation coefficient (r), ICC and Bland-Altman plot.ResultsThe repeatability assessment of the macular metrics exported high ICC values (ranged from 0.853 to 0.996). There is no statistically significant difference in the OCTA metrics between the two eyes. FAZ area (ICC=0.961, r=0.929) and FAZ perimeter (ICC=0.884, r=0.802) showed excellent binocular correlation. Fractal dimension (ICC=0.732, r=0.578) and VDI (ICC=0.707, r=0.547) showed moderate binocular correlation, while parafoveal vessel density had poor binocular correlation. Bland-Altman plots showed the range of agreement was from −0.0763 to 0.0954 mm2 for FAZ area and from −0.0491 to 0.1136 for parafoveal vessel density.ConclusionsThe macular metrics obtained using SS-OCTA showed excellent repeatability in healthy subjects. We showed high intereye correlation in FAZ area and perimeter, moderate correlation in fractal dimension and VDI, while vessel density had poor correlation in normal healthy subjects.

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Repeatability of ocular surface vessel density measurements with optical coherence tomography angiography

BMC Ophthalmology ◽

10.1186/s12886-019-1255-2 ◽

2019 ◽

Vol 19 (1) ◽

Author(s):

Sijie Cai ◽

Fengping Zhao ◽

Chixin Du

Keyword(s):

Optical Coherence Tomography ◽

Ocular Surface ◽

Optical Coherence Tomography Angiography ◽

Imaging System ◽

Intraclass Correlation ◽

Vessel Density ◽

Optical Coherence ◽

Significant Difference ◽

Surface Vessel ◽

Healthy Eyes

Abstract Background To determine the repeatability of measurements of ocular surface vessel density in normal and diseased eyes using optical coherence tomography angiography (OCTA). Methods Ten normal eyes, 10 pinguecula eyes, and 10 pterygium eyes of 30 volunteers were subjected to OCTA (AngioVue Imaging System, Optovue, Inc.). For scanning, we used the corneal adapter module. Each eye was scanned three times in the nasal and temporal directions, separately. AngioVue software was used to generate the ocular surface vessel density. Ocular surface vessel density was defined as the proportion of vessel area with blood flow to the total measurement area (3 × 3 mm2). Intersession repeatability of the measurement was summarized as the coefficient of variation (CV), and intraclass correlation coefficients (ICC) were calculated by variance component models. Results The CVs were less than 5% in all subjects, and the ICCs exceeded 0.9; thus, all measurements showed good repeatability. The nasal vessels densities differed significantly between healthy eyes and eyes with pterygium (P < 0.05); however, there was no significant difference between healthy eyes and eyes with pinguecula (P = 0.466). Conclusions These results suggest that measurement of ocular surface vessel density by OCTA in normal eyes and eyes with pterygium and pinguecula is repeatable. This preliminary research describes a quantitative and visual method for assessing vessel density of the ocular surface with a high level of consistency.

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VASCULAR PERFUSION DENSITY MAPPING USING OPTICAL COHERENCE TOMOGRAPHY ANGIOGRAPHY COMPARING NORMAL AND OPTIC DISK PIT EYES

Retinal Cases & Brief Reports ◽

10.1097/icb.0000000000000908 ◽

2019 ◽

Vol Publish Ahead of Print ◽

Cited By ~ 1

Author(s):

Shangjun Jiang ◽

Bryen Turco ◽

Netan Choudhry

Keyword(s):

Optical Coherence Tomography ◽

Optical Coherence Tomography Angiography ◽

Optic Disk ◽

Optical Coherence ◽

Vascular Perfusion ◽

Density Mapping ◽

Perfusion Density

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Intra-rater reliability of transversus abdominis measurement by a novice examiner: Comparison of “freehand” to “probe force device” method of real-time ultrasound imaging

Ultrasound ◽

10.1177/1742271x19831720 ◽

2019 ◽

Vol 27 (3) ◽

pp. 156-166 ◽

Cited By ~ 1

Author(s):

Vanessa L Kennedy ◽

Carol A Flavell ◽

Kenji Doma

Keyword(s):

Measurement Error ◽

Real Time ◽

Correlation Coefficient ◽

Intraclass Correlation Coefficient ◽

Coefficient Of Variation ◽

Repeated Measures ◽

Intraclass Correlation ◽

Transversus Abdominis ◽

Rater Reliability ◽

Transverse Abdominis

A “free hand” real-time-ultrasound method is commonly applied to measure transversus abdominis. Potentially, this increases transversus abdominis measurement error due to uncontrolled variability in probe to skin force, inclination, and roll, particularly for novice examiners. This single-group repeated-measures reliability study compared the intra-rater reliability of transversus abdominis thickness and activation measurement by a novice examiner between free hand and a standardized probe force device method. The examiner captured ultrasound videos of transversus abdominis in a single session in healthy participants ( n = 33). Free hand ultrasound featured uncontrolled probe force, inclination, and roll, while probe force device method ultrasound standardized these parameters. Images of transversus abdominis at rest and contracted were measured and transversus abdominis activation calculated. Intraclass correlation coefficient, coefficient of variation, standard error of measurement, and worthwhile differences were calculated. The probe force device method resulted in greater reliability (intraclass correlation coefficient = 0.75–0.96) and lower measurement error (coefficient of variation = 8.89–28.7%) compared to free hand (intraclass correlation coefficient = 0.63–0.93; coefficient of variation = 6.52–29.4%). Reliability was good for all measurements except free hand TrA-C, which was moderate. TrA-C had the lowest reliability, followed by contracted thickness of the transverse abdominis, with resting thickness of the transverse abdominis being highest. Worthwhile differences were lower using a probe force device method versus free hand for resting thickness of the transverse abdominis and contracted thickness of the transverse abdominis and similar for TrA-C. Standardization using probe force device method ultrasound to measure transversus abdominis improved intra-rater reliability in a novice examiner. Use of a probe force device method is recommended to improve reliability through reduced sources of measurement error. Probe force device method intra- and inter-rater reliability in examiners of varying experience, in clinical populations, and to visualize other structures merits exploration.

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Comparison of the Repeatability of Macular Vascular Density Measurements Using Four Optical Coherence Tomography Angiography Systems

Journal of Ophthalmology ◽

10.1155/2019/4372580 ◽

2019 ◽

Vol 2019 ◽

pp. 1-7 ◽

Cited By ~ 3

Author(s):

Jingyuan Yang ◽

Mingzhen Yuan ◽

Erqian Wang ◽

Youxin Chen

Keyword(s):

Optical Coherence Tomography ◽

Optical Coherence Tomography Angiography ◽

Intraclass Correlation ◽

Correlation Coefficients ◽

Vessel Density ◽

Vascular Density ◽

Optical Coherence ◽

Cross Sectional ◽

Capillary Plexus ◽

Scan Pattern

The aim of this study was to compare the repeatability of optical coherence tomography angiography (OCT-A) measurements of macular vessel density using four OCT-A systems, including Heidelberg Spectralis HRA, Optovue RTVue XR, Zeiss Cirrus HD-OCT 5000, and Topcon DRI OCT Triton. A cross-sectional design was used for this study. The vascular density and vascular length density of the superficial and deep retinal capillary plexuses were imaged with OCT-A using 3 mm and 6 mm scan patterns and were calculated using ImageJ. Comparisons of intraclass correlation coefficients (ICC) were conducted. We found that the OCT-A systems had various levels of repeatability. Zeiss had better repeatability for vessel density than the other systems (overall ICC = 0.936). Optovue had better repeatability for vessel length density when the 6 mm scan pattern was used (ICC = 0.680 and 0.700 for retinal superficial and deep capillary plexus, respectively). We concluded that repeatability varied when different scan patterns of various OCT-A systems were used for imaging the superficial retinal and deep capillary plexuses. Results should be seen as valid only for a given method. The repeatability of various OCT-A systems should be considered in clinical practice and in clinical trials that use OCT-A metrics as outcome measures.

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Optical coherence tomography angiography findings in patients undergoing transcorneal electrical stimulation for treating retinitis pigmentosa

Graefe s Archive for Clinical and Experimental Ophthalmology ◽

10.1007/s00417-020-04963-7 ◽

2020 ◽

Author(s):

Olga Zabek ◽

Hanna Camenzind Zuche ◽

Ursula Müller ◽

Hendrik P. N. Scholl ◽

Annekatrin Rickmann ◽

...

Keyword(s):

Optical Coherence Tomography ◽

Electrical Stimulation ◽

Retinitis Pigmentosa ◽

Optical Coherence Tomography Angiography ◽

Statistical Significance ◽

Vascular Density ◽

Optical Coherence ◽

Transcorneal Electrical Stimulation ◽

Retinal Layers ◽

Perfusion Density

Abstract Purpose Transcorneal electrical stimulation (TES) is a novel treatment approach for patients with retinitis pigmentosa (RP). The aim of our study was to observe changes in optical coherence tomography angiography (OCTA) that would be attributed to TES treatment. Methods A total of 73 eyes were included: 43 eyes of 22 subjects (11 ♀, 11 ♂) suffering from RP were examined at baseline (BL), after first stimulation (TS), 1 week (1W), and 6 months (6M) after treatment initiation and were compared with 30 control eyes of 15 subjects (8 ♀, 7 ♂). TES was performed simultaneously on both eyes for 30 min weekly. OCTA scans of 9 × 15 mm were recorded with a PLEX Elite 9000 swept-source OCTA device (Carl Zeiss Meditec AG, Jena). Vascular density metrics such as perfusion density (PD) and vessel density (VD) were calculated automatically for the macular area by using standardised extended early treatment diabetic retinopathy study (ETDRS) grids centred around the fovea. In addition, the capillary perfusion density (CPD) and the capillary flux index (CFI) of the peripapillary nerve fibre layer microvasculature in all four quadrants of an annulus centred at the optic disc were measured. All parameters were determined over all retinal layers and separately for the superficial (SCP) and deep capillary plexus (DCP). ANOVA-based linear mixed-effects models were calculated with SPSS®. Results Throughout the course of TES treatment, the macular VD and PD of all retinal layers in all subsections showed a slight decrement without reaching statistical significance, also when analysed separately in the SCP and DCP (p > 0.08). In analogy, the average CPD and CFI also presented with a slight decrement (p > 0.20). However, when compared with controls, most OCTA parameters showed a significant decrement (p < 0.05). When analysed systematically in all subsections of the extended ETDRS grid, the temporal macular subsections within the outer ring (radius 1.5–3 mm) and also of the peripheral C1, C2, and C3 rings (radius 3–7.5 mm) showed lower VD and PD values when compared with the other subsections (p < 0.05). Conclusion Vascular density metrics in the macular region and the peripapillary microvasculature appear to remain unaffected by continuous TES treatment within a period of 6 months.

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Repeatability of vessel density measurements of optical coherence tomography angiography in normal and glaucoma eyes

British Journal of Ophthalmology ◽

10.1136/bjophthalmol-2017-310637 ◽

2017 ◽

Vol 102 (3) ◽

pp. 352-357 ◽

Cited By ~ 55

Author(s):

Jayasree P Venugopal ◽

Harsha L Rao ◽

Robert N Weinreb ◽

Zia S Pradhan ◽

Srilakshmi Dasari ◽

...

Keyword(s):

Optical Coherence Tomography ◽

Repeated Measures ◽

Optical Coherence Tomography Angiography ◽

Signal Strength ◽

Cross Sectional Study ◽

Vessel Density ◽

Optical Coherence ◽

Cross Sectional ◽

Density Measurements ◽

Density Values

AimsTo compare the intrasession repeatability of peripapillary and macular vessel density measurements of optical coherence tomography angiography (OCTA) in normal and glaucoma eyes, and to evaluate the effect of signal strength of OCTA scans on the repeatability.MethodsIn a cross-sectional study, three optic nerve head scans each of 65 eyes (30 normal, 35 glaucoma eyes) and three macular scans each of 69 eyes (35 normal, 34 glaucoma eyes) acquired in the same session with OCTA were analysed. Repeatability was assessed using within-subject coefficient of repeatability (CRw) and variation (CVw). Effect of signal strength index (SSI) on repeatability was evaluated with repeated-measures mixed-effects models.ResultsCRw (%) and CVw (%) of peripapillary measurements in normal eyes ranged between 3.3 and 7.0, and 2.5 and 4.4 respectively, and that in glaucoma eyes between 3.5 and 7.1, and 2.6 and 6.6. For the macular, these measurements ranged between 4.1 and 6.0, and 3.3 and 4.7 in normal eyes and 4.3 and 6.9, and 3.7 and 5.6 in glaucoma eyes. Repeatability estimates of most measurements were similar in normal and glaucoma eyes. Vessel densities of both peripapillary and macular regions significantly increased with increase in SSI of repeat scans (coefficients ranging from 0.15 to 0.38, p<0.01 for all associations).ConclusionsRepeatability estimates of OCTA measured peripapillary and macular vessel densities were similar in normal eyes and eyes with glaucoma. SSI values of the scans had a significant effect on the repeatability of OCTA with the vessel density values increasing in scans with higher SSI values.

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