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

2018 ◽  
Vol 103 (3) ◽  
pp. 415-420 ◽  
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.

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

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.

scholarly journals Quantitative assessment of choriocapillaris flow deficits in diabetic retinopathy: A swept-source optical coherence tomography angiography study

PLoS ONE ◽  
2020 ◽  
Vol 15 (12) ◽  
pp. e0243830
Author(s):  
Yining Dai ◽  
Hao Zhou ◽  
Qinqin Zhang ◽  
Zhongdi Chu ◽  
Lisa C. Olmos de Koo ◽  
...  
Keyword(s):  
Optical Coherence Tomography ◽  
Diabetic Retinopathy ◽  
Healthy Subjects ◽  
Optical Coherence Tomography Angiography ◽  
Optical Coherence ◽  
Swept Source ◽  
Significant Difference ◽  
En Face ◽  
The Mean

Purpose To quantitatively assess choriocapillaris (CC) flow deficits in eyes with diabetic retinopathy (DR) using swept-source optical coherence tomography angiography (SS-OCTA). Methods Diabetic subjects with different stages of DR and age-matched healthy subjects were recruited and imaged with SS-OCTA. The en face CC blood flow images were generated using previously published and validated algorithms. The percentage of CC flow deficits (FD%) and the mean CC flow deficit size were calculated in a 5-mm-diameter circle centered on the fovea from the 6×6-mm scans. Results Forty-five diabetic subjects and 27 control subjects were included in the study. The CC FD% in diabetic eyes was on average 1.4-fold greater than in control eyes (12.34±4.14% vs 8.82±2.61%, P < 0.001). The mean CC FD size in diabetic eyes was on average 1.4-fold larger than in control eyes (2151.3± 650.8μm2 vs 1574.4±255.0 μm2, P < 0.001). No significant difference in CC FD% or mean CC FD size was observed between eyes with nonproliferative DR and eyes with proliferative DR (P = 1.000 and P = 1.000, respectively). Conclusions CC perfusion in DR can be objectively and quantitatively assessed with FD% and FD size. In the macular region, both CC FD% and CC FD size are increased in eyes with DR. SS-OCTA provides new insights for the investigations of CC perfusion status in diabetes in vivo.

Intra- and Interdevice Deviation of Optical Coherence Tomography Angiography

2019 ◽  
Vol 236 (04) ◽  
pp. 551-554 ◽  
Author(s):  
Stefan Trachsler ◽  
Arthur Baston ◽  
Marcel Menke
Keyword(s):  
Optical Coherence Tomography ◽  
Healthy Subjects ◽  
Optical Coherence Tomography Angiography ◽  
Foveal Avascular Zone ◽  
Optical Coherence ◽  
Swept Source ◽  
Significant Difference ◽  
Capillary Plexus ◽  
Swept Source Oct ◽  
Scan Modes

Abstract Purpose To compare 4 optical coherence tomography-angiography (OCT-A) devices for foveal avascular zone (FAZ) measurements in healthy subjects. Methods The central retinas of 24 eyes of 12 healthy subjects were scanned with 4 different OCT-A devices (Optovue RTVue-XR, Zeiss Cirrus 5000-HD-OCT, a prototype Spectralis OCT2, Heidelberg Engineering, and Topcon DRI-OCT Triton Swept-source OCT). For the Topcon, Zeiss, and Optovue devices, 3-mm and 6-mm scans were performed. The Heidelberg device only provided 4-mm scans. En-face OCT-A images of the superficial and deep capillary plexus of the macular area were generated. The FAZ areas were measured and compared. Results Twenty-four healthy eyes were included. OCT-A devices showed significant differences in FAZ measurements. The Zeiss OCT-A device measured the smallest values for foveal avascular area (mean 218.7 mm2), followed by the Optovue device (229.6 mm2), the Topcon device (239.3 mm2), and the Heidelberg device (250.4 mm2). Differences were statistically significant for following devices: Heidelberg versus Optovue (p < 0.001), Heidelberg versus Zeiss (p < 0.001), Topcon versus Zeiss (p < 0.001), and Optovue versus Zeiss (p = 0.046). For the Optovue device, FAZ measurements were significantly different between 3 mm (mean 220 mm2) and 6 mm (mean 239.3 mm2, p = 0.007) scans. All other devices showed no significant difference within scan modes. Conclusion Current OCT-A devices provide images that allow such measurements, but values showed significant differences between devices and, for the Optovue instrument, even within scan modes. The data for OCTA measurements cannot be transferred interchangeably between the devices. Therefore, a patient should always be measured with the same device.

Reproducibility and Repeatability of Foveal Avascular Zone Area Measurements Using Swept-Source Optical Coherence Tomography Angiography in Healthy Subjects

2016 ◽  
Vol 27 (3) ◽  
pp. 336-341 ◽  
Author(s):  
Rodolfo Mastropasqua ◽  
Lisa Toto ◽  
Peter A. Mattei ◽  
Marta Di Nicola ◽  
Isaia A.L. Zecca ◽  
...  
Keyword(s):  
Optical Coherence Tomography ◽  
Healthy Subjects ◽  
Optical Coherence Tomography Angiography ◽  
Intraclass Correlation ◽  
Correlation Coefficients ◽  
Foveal Avascular Zone ◽  
Optical Coherence ◽  
Swept Source ◽  
Avascular Zone ◽  
Within Subjects

Purpose To assess the reproducibility and repeatability of foveal avascular zone (FAZ) area measurements using swept-source optical coherence tomography angiography (SS-OCTA) in healthy subjects. Methods Sixty-four eyes of 64 healthy volunteers were randomly subjected to FAZ area measurements using SS-OCTA by 2 examiners in 2 different sessions. Results The FAZ areas measured by the first and second observer were 0.269 ± 0.092 mm2 and 0.270 ± 0.090 mm2, respectively. Within subjects, the coefficients of variations were 2.44% (95% confidence interval [CI] 1.95% to 2.93%) and 2.66% (95% CI 2.00% to 3.31%) for the first and second observers, respectively. The coefficient of repeatability average measurements of FAZ area were 0.021 mm2 and 0.024 mm2. The intraclass correlation coefficient values were 0.993 (95% CI 0.989 to 0.996) and 0.991 (95% CI 0.986 to 0.995). Interobserver and intraobserver concordance correlation coefficients ranged from 0.998 (95% CI 0.997 to 0.999) to 0.999 (95% CI 0.998 to 0.999) and from 0.989 (95% CI 0.982 to 0.993) to 0.987 (95% CI 0.979 to 0.992), respectively. Conclusions The FAZ area measurements by means of SS-OCTA showed high reproducibility and repeatability in healthy eyes.

scholarly journals Swept Source Optical Coherence Tomography Angiography for Contact Lens-Related Corneal Vascularization

2016 ◽  
Vol 2016 ◽  
pp. 1-3 ◽  
Author(s):  
Marcus Ang ◽  
Yijun Cai ◽  
Anna C. S. Tan
Keyword(s):  
Optical Coherence Tomography ◽  
Image Quality ◽  
Contact Lens ◽  
Optical Coherence Tomography Angiography ◽  
Quality Score ◽  
Image Quality Score ◽  
Optical Coherence ◽  
Swept Source ◽  
Corneal Vascularization ◽  
Significant Difference

Purpose. To describe a novel technique of adapting a swept-source optical coherence tomography angiography (OCTA) to image corneal vascularization.Methods. In this pilot cross-sectional study, we obtained 3 × 3 mm scans, where 100,000 A-scans are acquired per second with optical axial resolution of 8 μm and lateral resolution of 20 μm. This was performed with manual “XYZ” focus without the anterior segment lens, until the focus of the corneoscleral surface was clearly seen and the vessels of interest were in focus on the corresponding red-free image. En face scans were evaluated based on image quality score and repeatability.Results. We analyzed scans from 10 eyes (10 patients) with corneal vascularization secondary to contact lens use in 4 quadrants, with substantial repeatability of scans in all quadrants (mean image quality score 2.7 ± 0.7;κ=0.75). There was no significant difference in image quality scores comparing quadrants (superior temporal: 2.9 ± 0.6, superior nasal: 2.8 ± 0.4, inferior temporal: 2.5 ± 0.9, and inferior nasal: 2.4 ± 1.0;P=0.276) and able to differentiate deep and superficial corneal vascularization.Conclusion. This early clinical study suggests that the swept-source OCTA used may be useful for examining corneal vascularization, which may have potential for clinical applications such as detecting early limbal stem cell damage.

scholarly journals Comparison of two different optical coherence tomography angiography devices in detecting healthy versus glaucomatous eyes – an observational cross-sectional study

2020 ◽  
Vol 20 (1) ◽  
Author(s):  
A. R. Kee ◽  
V. C. H. Yip ◽  
E. L. T. Tay ◽  
C. W. Lim ◽  
J. Cheng ◽  
...  
Keyword(s):  
Optical Coherence Tomography ◽  
Diagnostic Accuracy ◽  
Optic Disc ◽  
Optical Coherence Tomography Angiography ◽  
Optical Coherence ◽  
Cross Sectional ◽  
Swept Source ◽  
Retest Reliability ◽  
Significant Difference ◽  
Test Retest Reliability

Abstract Background To understand the differences between two different optical coherence tomography angiography (OCTA) devices in detecting glaucomatous from healthy eyes by comparing their vascular parameters, diagnostic accuracy and test-retest reliability. Methods A cross-sectional observational study was performed on healthy and glaucoma subjects, on whom two sets of OCTA images of optic disc and macula were acquired using both AngioVue (Optovue, USA) and Swept Source (Topcon, Japan) OCTA devices during one visit. A novel in-house software was used to calculate the vessel densities. Diagnostic accuracy of the machines in differentiating healthy versus glaucomatous eyes was determined using area under the receiver operating characteristic curve (AUROC) and test-retest repeatability of the machines was also evaluated. Results A total of 80 healthy and 38 glaucomatous eyes were evaluated. Glaucomatous eyes had reduced mean vessel density compared to healthy controls in all segmented layers of the optic disc and macula using AngioVue (p ≤ 0.001). However, glaucomatous eyes had higher mean vessel density on optic disc scans using Swept Source, with lack of statistically significant difference between healthy and glaucomatous eyes. The AUROC showed better diagnostic accuracy of AngioVue (0.761–1.000) compared to Swept Source (0.113–0.644). The test-retest reliability indices were generally better using AngioVue than Swept Source. Conclusions AngioVue showed better diagnostic capability and test-retest reliability compared to Swept Source. Further studies need to be undertaken to evaluate if there is any significant difference between the various machines in diagnosing and monitoring glaucoma.

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

2019 ◽  
Vol 2019 ◽  
pp. 1-7 ◽  
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.

Anterior segment optical coherence tomography angiography for iris vasculature in pigmented eyes

2020 ◽  
pp. bjophthalmol-2020-316930
Author(s):  
Marcus Ang ◽  
Kavya Devarajan ◽  
Anna CS Tan ◽  
Mengyuan Ke ◽  
Bingyao Tan ◽  
...  
Keyword(s):  
Optical Coherence Tomography ◽  
Optical Coherence Tomography Angiography ◽  
Anterior Segment ◽  
Mean Difference ◽  
Vessel Density ◽  
Optical Coherence ◽  
Swept Source ◽  
Density Measurements ◽  
Stage 1 ◽  
Swept Source Octa

PurposeTo compare anterior segment optical coherence tomography angiography (AS-OCTA) systems in delineating normal iris vessels and iris neovascularisation (NVI) in eyes with pigmented irides.MethodsProspective study from January 2019 to June 2019 of 10 consecutive patients with normal pigmented iris, had AS-OCTA scans with a described illumination technique, before using the same protocol in five eyes with NVI (clinical stages 1–3). All scans were sequentially performed using a spectral-domain OCTA (SD-OCTA), and a swept-source OCTA (SS-OCTA, Plex Elite 9000). Images were graded by two masked observers for visibility, artefacts and NVI characteristics. The main outcome measure was iris vessel density measurements comparing SS-OCTA and SD-OCTA systems.ResultsThe median age of subjects was 28 (20–35) years, and 50% were female. The paired mean difference of iris vessel density measurements was 11.7 (95% CI 14.7 to 8.1; p=0.002), SS-OCTA detecting more vessels than SD-OCTA. The inter-rater reliability for artefact score (κ=0.799, p<0.001) and visibility score (κ=0.722; p<0.001) were substantial. Both AS-OCTA systems were able to detect NVI vessels with a fair agreement (κ=0.588), with clearer NVI characteristics in stage 1/2 compared to stage 3 NVI (mean difference NVI score: 2.7±0.4, p=0.009).ConclusionThe SS-OCTA was better able to delineate iris vessels in normal pigmented irides compared to SD-OCTA. Both AS-OCTA systems identified NVI characteristics based on its atypical configuration or location, but further improvements are needed to allow for more accurate objective, serial quantification for clinical use.

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