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

2017 ◽  
Vol 102 (3) ◽  
pp. 352-357 ◽  
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.

scholarly journals Association of Myopia With Microvascular Alterations in Patients With Type 2 Diabetes: An Optical Coherence Tomography Angiography Study

2021 ◽  
Vol 8 ◽  
Author(s):  
Xin Wen ◽  
Zijing Li ◽  
Jianhui Xiao ◽  
Xuane Liu ◽  
Yichi Zhang ◽  
...  
Keyword(s):  
Type 2 Diabetes ◽  
Optical Coherence Tomography ◽  
Optical Coherence Tomography Angiography ◽  
Cross Sectional Study ◽  
Vessel Density ◽  
Diabetic Patients ◽  
Optical Coherence ◽  
Fiber Layer ◽  
Cross Sectional

Purpose: To determine the association of myopia with peripapillary and macular microvasculature in eyes with type 2 diabetes using optical coherence tomography angiography (OCTA).Methods: Diabetic patients with and without diabetic retinopathy (DR) were recruited and grouped according to myopic status in this cross-sectional study. Axial length, refractive error, and OCTA parameters were measured. OCTA parameters were analyzed with adjustment of confounding factors and further Bonferroni analysis was performed to determine the differences in multiple group comparisons.Results: Compared with the diabetic eyes without myopia, those with myopia had lower rate of DR (21.82 vs. 35.90%, χ2 = 6.190, P = 0.013), longer axial lengths (24.94 ± 0.75 vs. 23.16 ± 0.64, F = 311.055, P &lt; 0.001) and reduced whole vessel density (VD) of optic nerve head (ONH) (45.89 ± 5.76 vs. 49.14 ± 4.33, F = 19.052, P &lt; 0.001), peripapillary VD (48.75 ± 6.56 vs. 50.76 ± 4.51, F = 7.600, P = 0.006), and reduced thickness of the retinal nerve fiber layer (RNFL) (95.50 ± 12.35 vs. 100.67 ± 13.68, F = 5.020, P = 0.026). In eyes without myopia, the superficial vessel density (SVD) (46.58 ± 4.90 vs. 43.01 ± 4.25; 95% CI, 1.80–4.61; P &lt; 0.001), deep vessel density (DVD) (45.64 ± 6.34 vs. 42.15 ± 6.31; 95% CI, 1.07–5.00; P &lt; 0.001), and FD300 area density (50.31 ± 5.74 vs. 44.95 ± 6.96; 95% CI, 2.88–7.27; P &lt; 0.001) were significant reduced in eyes with DR(DR eyes) comparing to those without DR (NoDR eyes). In eyes with myopia, only SVD were significantly reduced in DR eyes comparing to NoDR eyes (41.68 ± 3.34 vs. 45.99 ± 4.17; 95% CI, 1.10–7.22; P = 0.002). In NoDR eyes, both whole VD of ONH and Peripapillary VD demonstrated a significant decrease in eyes with myopia comparing to those without myopia (49.91 ± 4.36 vs. 45.61 ± 6.32; 95% CI, 1.95–6.27; P &lt; 0.001 and 51.36 ± 4.24 vs. 48.52 ± 6.99; 95% CI, 0.56–5.11; P = 0.006, respectively).Conclusions: In diabetic patients, myopic eyes exhibited lower prevalence of DR and thinner thickness of RNFL. The refractive status could possibly impact the retinal microvascular changes from NoDR to DR stage.

scholarly journals Vessel Density and Retinal Thickness from Optical Coherence Tomography Angiography as New Indexes in Adolescent Myopia

2021 ◽  
Vol 2021 ◽  
pp. 1-7
Author(s):  
Qin Zhu ◽  
Chunwen Chen ◽  
Jingyan Yao
Keyword(s):  
Optical Coherence Tomography ◽  
Optical Coherence Tomography Angiography ◽  
Retinal Thickness ◽  
Blood Perfusion ◽  
Cross Sectional Study ◽  
Vessel Density ◽  
Optical Coherence ◽  
Cross Sectional ◽  
Foveal Region ◽  
Almost All

Purpose. To evaluate and quantify blood perfusion and retinal thickness (RT) from the perspective of quadrants by optical coherence tomography angiography (OCTA) in adolescents with myopia and explore the relationship between axial elongation and related indexes of OCTA. Methods. A total of 88 subjects (149 eyes) with different degrees of myopia were included in this cross-sectional study. Vessel density (VD) and RT of quadrants in macular and peripheral regions were measured through OCTA. Results. The superficial VD (SVD) of the parainferior region was significantly correlated with axial length (AL) between the emmetropia (EM) group and high myopia (HI) group ( P = 0.012 ). There were significant differences in deep VD (DVD) in all quadrants, except for the foveal, perifoveal, and peri-inferior regions ( P > 0.05 ). However, there were significant alterations in the whole, parainferior, and perinasal regions ( P = 0.030 , 0.023, and 0.035) in the low-to-moderate myopia (L–M) group compared with those in the HI group. There were significant differences in the RT in all quadrants, except for the foveal, paratemporal, and paranasal regions ( P > 0.05 ) between the EM and L–M groups and the foveal region ( P > 0.05 ) between the EM and HI groups. Nevertheless, only RT in the peri-inferior region of the L–M and HI groups showed significant differences. AL was negatively correlated with SVD in the perifoveal and parainferior regions (r = −0.179, P = 0.029 ; r = −0.227, P = 0.005 ) and inversely correlated with DVD and RT in almost all quadrants, except for the foveal region (r = −0.020, P = 0.811 ; r = 0.135, P = 1.000 ). Conclusion. DVD and RT were closely associated with the severity of myopia and might be new indexes in assessing and detecting myopia development via OCTA.

Repeatability and comparability of peripapillary vessel density measurements of high-density and non-high-density optical coherence tomography angiography scans in normal and glaucoma eyes

2018 ◽  
Vol 103 (7) ◽  
pp. 949-954 ◽  
Author(s):  
Jayasree P Venugopal ◽  
Harsha Laxmana Rao ◽  
Robert N Weinreb ◽  
Srilakshmi Dasari ◽  
Mohammed Riyazuddin ◽  
...  
Keyword(s):  
Optical Coherence Tomography ◽  
Optical Coherence Tomography Angiography ◽  
Cross Sectional Study ◽  
High Density ◽  
Vessel Density ◽  
Optical Coherence ◽  
Sectional Study ◽  
Limits Of Agreement ◽  
Cross Sectional ◽  
The Mean

AimsTo compare the peripapillary vessel density (VD) measurements of high-density (HD) and non-HD optical coherence tomography angiography (OCTA) scans in normal and glaucoma eyes, and to evaluate the intrasession repeatability of VD measurements of HD scans.MethodsIn a cross-sectional study, 46 normal (33 subjects) and 89 glaucoma (64 patients) eyes underwent 3 HD and 1 non-HD optic nerve head OCTA scans in the same session. Agreement in VD measurements between HD and non-HD scans was assessed using Bland and Altman analysis. Repeatability of the VD measurements of HD scans was assessed using within-subject coefficient of repeatability (CRw) and variation (CVw).ResultsThe mean difference in the VDs ranged between 0.7% (temporal sector VD) and 2.0% (inferonasal sector VD), with HD scans showing significantly greater VD values than non-HD scans. The 95% limits of agreement (LoA) in glaucoma eyes ranged between −2.0% and 5.0% for whole enface VD and between −4.8% and 9.6% for superotemporal VD. CRw (%) and CVw (%) of VD measurements of HD scans ranged from 3.0 to 4.9 and from 2.0 to 3.1 in normal eyes. The same ranged from 3.2 to 6.7 and from 2.6 to 4.8, respectively, in glaucoma eyes.ConclusionsVD of HD scans was higher than that of non-HD scans. The wide 95% LoA indicates that the VD measurements of HD and non-HD scans cannot be used interchangeably. Test–retest repeatability of VDs on HD scans was as high as 6%. These results should be considered while using OCTA for longitudinal evaluation of glaucoma.

Comparison of anterior segment optical coherence tomography angiography systems for corneal vascularisation

2017 ◽  
Vol 102 (7) ◽  
pp. 873-877 ◽  
Author(s):  
Marcus Ang ◽  
Kavya Devarajan ◽  
Suchandrima Das ◽  
Tisha Stanzel ◽  
Anna Tan ◽  
...  
Keyword(s):  
Optical Coherence Tomography ◽  
Image Quality ◽  
Optical Coherence Tomography Angiography ◽  
Anterior Segment ◽  
Case Series ◽  
Vessel Density ◽  
Optical Coherence ◽  
Cross Sectional ◽  
Density Measurements ◽  
Split Spectrum

AimTo newly describe a spectral-domain (SD) optical coherence tomography angiography (OCTA) for the cornea and directly compare two OCTA system scans of the same eyes with corneal vascularisation.MethodsCross-sectional, observational, comparative case series. We performed sequential OCTA scans (10 eyes of 10 subjects with corneal vascularisation,4 scans each eye) repeated using split-spectrum amplitude decorrelation algorithm angiography system (SSADA, AngioVue; Optovue Inc, USA) and SD OCTA (Angioscan; Nidek Co. Ltd, Japan) in the same region of interest. We analysed all scan images for repeatability, image quality and vessel density measurements and compared OCTA systems.ResultsWe obtained substantial interobserver repeatability in terms of image quality score (κ=0.86) for all 80 OCTA scans (median age 49 years, 50% women). The correlation was moderately good (r=0.721) when comparing vessel density measurements between OCTA systems, but greater in the SSADA compared with SD OCTA system (mean vessel density 20.3±4.9% vs 15.1±4.2%, respectively; p<0.001).ConclusionIn this pilot clinical study, we describe successful delineation of corneal vessels with substantial image quality using a new SD OCTA system. The vessel density measurements were greater using the SSADA compared with SD OCTA system in the same area of corneal vascularisation. Further studies are required to confirm the advantages, limitations and differences between these OCTA systems for the anterior segment.

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.

scholarly journals Stepwise segmentation error correction in optical coherence tomography angiography images of patients with diabetic macular edema

2020 ◽  
Vol 12 ◽  
pp. 251584142094793
Author(s):  
Khalil Ghasemi Falavarjani ◽  
Reza Mirshahi ◽  
Shahriar Ghasemizadeh ◽  
Mahsa Sardarinia
Keyword(s):  
Optical Coherence Tomography ◽  
Macular Edema ◽  
Diabetic Macular Edema ◽  
Optical Coherence Tomography Angiography ◽  
Plexiform Layer ◽  
Vessel Density ◽  
Inner Plexiform Layer ◽  
Optical Coherence ◽  
Density Measurements ◽  
Segmentation Error

Aim: To determine the minimum number of optical coherence tomography B-scan corrections required to provide acceptable vessel density measurements on optical coherence tomography angiography images in eyes with diabetic macular edema. Methods: In this prospective, noninterventional case series, the optical coherence tomography angiography images of eyes with center-involving diabetic macular edema were assessed. Optical coherence tomography angiography imaging was performed using RTVue Avanti spectral-domain optical coherence tomography system with the AngioVue software (V.2017.1.0.151; Optovue, Fremont, CA, USA). Segmentation error was recorded and manually corrected in the inner retinal layers in the central foveal, 100th and 200th optical coherence tomography B-scans. The segmentation error correction was then continued until all optical coherence tomography B-scans in whole en face image were corrected. At each step, the manual correction of each optical coherence tomography B-scan was propagated to whole image. The vessel density and retinal thickness were recorded at baseline and after each optical coherence tomography B-scan correction. Results: A total of 36 eyes of 26 patients were included. To achieve full segmentation error correction in whole en face image, an average of 1.72 ± 1.81 and 5.57 ± 3.87 B-scans was corrected in inner plexiform layer and outer plexiform layer, respectively. The change in the vessel density measurements after complete segmentation error correction was statistically significant after inner plexiform layer correction. However, no statistically significant change in vessel density was found after manual correction of the outer plexiform layer. The vessel density measurements were statistically significantly different after single central foveal B-scan correction of inner plexiform layer compared with the baseline measurements ( p = 0.03); however, it remained unchanged after further segmentation corrections of inner plexiform layer. Conclusion: Multiple optical coherence tomography B-scans should be manually corrected to address segmentation error in whole images of en face optical coherence tomography angiography in eyes with diabetic macular edema. Correction of central foveal B-scan provides the most significant change in vessel density measurements in eyes with diabetic macular edema.

scholarly journals Exploring the association of collaterals and vessel density using optical coherence tomography angiography in retinal vein occlusions

2019 ◽  
Author(s):  
Hee Eun Lee ◽  
Yiyang Wang ◽  
Alaa E. Fayed ◽  
Amani A. Fawzi
Keyword(s):  
Optical Coherence Tomography ◽  
Clustering Algorithm ◽  
Optical Coherence Tomography Angiography ◽  
Vessel Density ◽  
P Value ◽  
Study Cohort ◽  
Optical Coherence ◽  
Capillary Perfusion ◽  
Cross Sectional ◽  
Entire Study

AbstractPurposeUsing optical coherence tomography angiography (OCTA) to characterize the types of collaterals in eyes with retinal vein occlusion (RVO) and further investigate their correlations with vessel densities of the superficial (SCP) and the deep capillary plexus (DCP).MethodsThis cross-sectional study included 25 eyes of 23 patients with RVO. 3 × 3 mm2 OCTA macular scans were used to quantify the parafoveal vessel density (VD) of the SCP and DCP, and to classify the collaterals into one of four types (true superficial, true deep, superficial diving, and foveal collateral). Poisson regression model was used to identify significant associations between parafoveal VD and collaterals. We further compared parafoveal VD between subgroups classified by the presence of specific collateral types based on the results of a clustering algorithm.Results16 of 25 eyes (64%) developed collaterals. Of the 43 collateral vessels analyzed, 12/19 (63%) true superficial collaterals developed in eyes with central RVO, while all 10 superficial diving collaterals (100%) developed in eyes with branch RVO. Located exclusively in the SCP, true superficial collaterals were all arteriovenous (A-V), while diving collaterals were all veno-venular (V-V). We found a significant negative correlation between SCP VD and the total number of collaterals (R2 = 0.648, P < 0.001) for the entire study cohort. Furthermore, BRVO eyes that developed superficial diving collaterals and CRVO eyes that developed true superficial collaterals demonstrated statistically significant decrease in SCP VD (P-value = 0.014) and DCP VD (P-value = 0.030), respectively, as compared to their counterparts.ConclusionOur data shows that decreased capillary perfusion in RVO is associated with the development of collaterals, while the RVO type largely dictates the type of collateral that ultimately develops.

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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