Effect of segmentation error correction on optical coherence tomography angiography measurements in healthy subjects and diabetic macular oedema

2019 ◽  
Vol 104 (2) ◽  
pp. 162-166 ◽  
Author(s):  
Khalil Ghasemi Falavarjani ◽  
Abbas Habibi ◽  
Pasha Anvari ◽  
Shahriar Ghasemizadeh ◽  
Maryam Ashraf Khorasani ◽  
...  
Keyword(s):  
Optical Coherence Tomography ◽  
Macular Oedema ◽  
Optical Coherence Tomography Angiography ◽  
Retinal Thickness ◽  
Diabetic Macular Oedema ◽  
Vessel Density ◽  
Density Measurements ◽  
Segmentation Error ◽  
The Mean ◽  
Healthy Eyes

PurposeTo evaluate the impact of segmentation error on vessel density measurements in healthy eyes and eyes with diabetic macular oedema (DMO).MethodsIn this prospective, comparative, non-interventional study, enface optical coherence tomography angiography (OCTA) images of the macula from healthy eyes and eyes with DMO were acquired. Two expert graders assessed and corrected the segmentation error. The rate of segmentation error and the changes in vessel density and inner retinal thickness after correction of the segmentation error were recorded and compared between the two groups.Results20 eyes with DMO and 24 healthy eyes were evaluated. Intergrader agreement was excellent (intraclass correlation coefficient ≥0.9) for all parameters in both groups. The rate of segmentation error was 33% and 100% in healthy and diabetic eyes, respectively (p<0.001). Nine healthy eyes (37.5%) and all eyes with DMO (100%) were noted to exhibit a change in at least one of the foveal or parafoveal vessel density measurements. The rate of any change in foveal and parafoveal vessel densities in both the superficial and deep capillary plexus was statistically significantly higher in the diabetic group (all p<0.001). No statistically significant change was observed in mean vessel density (superficial and deep capillary plexuses) after correction of the segmentation error in healthy and DMO eyes (All p>0.05). However, the mean absolute change in the vessel density measurements was statistically significantly higher in the diabetic group (all p<0.05). The mean absolute change in superficial and deep inner retinal thickness was statistically significantly higher in DMO (p=0.02 and p=0.002, respectively).ConclusionsIn this study, misidentification of retinal layers and consequent vessel density measurement error occurred in all eyes with DMO and in one-third of healthy eyes. The segmentation error should be checked and manually corrected in the OCTA vessel density measurements, especially in the presence of macular oedema.

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 Repeatability of vessel density measurements using optical coherence tomography angiography in retinal diseases

2018 ◽  
Vol 103 (5) ◽  
pp. 704-710 ◽  
Author(s):  
Min-Woo Lee ◽  
Kyeung-Min Kim ◽  
Hyung-Bin Lim ◽  
Young-Joon Jo ◽  
Jung-Yeul Kim
Keyword(s):  
Optical Coherence Tomography ◽  
Macular Oedema ◽  
Optical Coherence Tomography Angiography ◽  
Signal Strength ◽  
Vessel Density ◽  
Age Related Macular Degeneration ◽  
Inner Plexiform Layer ◽  
Retinal Diseases ◽  
Optical Coherence ◽  
The Mean

AimTo analyse the repeatability of vessel density (VD) measurements using optical coherence tomography angiography (OCTA) in patients with retinal diseases.MethodsTwo consecutive VD measurements using OCTA were analysed prospectively in patients with retinal diseases (diabetic macular oedema (DME), retinal vein occlusion (RVO) with macular oedema, epiretinal membrane (ERM), wet age-related macular degeneration (AMD)). The intraclass correlation coefficient (ICC), coefficient of variation (CV) and test-retest SD of VD measurements were assessed, and linear regression analyses were conducted to identify factors related to repeatability.ResultsA total of 134 eyes were analysed involving 20 eyes with DME, 44 eyes with RVO with macular oedema, 50 eyes with ERM and 20 eyes with wet AMD. The mean age was 64.9 years, and the mean best-corrected visual acuity (BCVA) was 0.24. The mean central macular thickness (CMT) was 391.6 µm, and the mean ganglion cell-inner plexiform layer (GC-IPL) thickness was 61.4 µm. In all four diseases, the ICC and CV of the full VD were 0.812 and 6.72%, respectively. Univariate analyses showed that the BCVA (B, 8.553; p=0.031), signal strength (B, −1.688; p=0.050), CMT (B, 0.019; p=0.015) and mean GC-IPL thickness (B, −0.103; p=0.001) were significant factors that affected the repeatability. Multivariate analyses of these factors showed a significant result for the GC-IPL thickness.ConclusionsMeasurements of the VD using OCTA showed relatively good repeatability for various retinal diseases. The BCVA, signal strength, CMT and GC-IPL thickness affected the repeatability, so these factors should be considered when analysing the VD.

scholarly journals The Role of Optical Coherence Tomography Angiography in Moderate and Advanced Primary Open-Angle Glaucoma

2021 ◽  
Author(s):  
Yadollah Eslami ◽  
Sepideh Ghods ◽  
Massood Mohammadi ◽  
Mona Safizadeh ◽  
Ghasem Fakhraie ◽  
...  
Keyword(s):  
Optical Coherence Tomography ◽  
Optical Coherence Tomography Angiography ◽  
Primary Open Angle Glaucoma ◽  
Open Angle Glaucoma ◽  
Vessel Density ◽  
Mean Deviation ◽  
Optical Coherence ◽  
Open Angle ◽  
The Mean ◽  
Inferior Quadrant

Abstract Purpose: To evaluate the relationship between structure and function in moderate and advanced primary open-angle glaucoma (POAG) and to determine the accuracy of structure and vasculature for discriminating moderate from advanced POAG.Methods: In this cross-sectional study 25 eyes with moderate and 40 eyes with advanced POAG were enrolled. All eyes underwent measurement of the thickness of circumpapillary retinal nerve fiber layer (cpRNFL) and macular ganglion cell complex (GCC), and optical coherence tomography angiography (OCTA) of the optic nerve head (ONH) and macula. Visual field (VF) was evaluated by Swedish interactive threshold algorithm and 24-2 and 10-2 patterns. The correlation between structure and vasculature and the mean deviation (MD) of the VFs was evaluated by a partial correlation coefficient. The area under the receiver operating characteristic curve (AUC) was applied for assessing the power of variables for discrimination moderate from advanced POAG.Results: Superior cpRNFL, superior GCC, whole image vessel density (wiVD) of the ONH area, and vessel density in inferior quadrant of perifovea had the strongest correlation with the mean deviation (MD) of the VF 24-2 (r= .351, .558, .649 and .397; p< .05). The greatest AUCs belonged to inferior cpRNFL (.789), superior GCC (.818), vessel density of the inferior hemifield of ONH area (.886), and vessel density in inferior quadrant of perifovea (.833) without statistically significant difference in pairwise comparison.Conclusion: Vasculature has a stronger correlation than the structure with MD in moderate and advanced POAG and is as accurate as structure in discrimination moderate from advanced POAG.

Optical coherence tomography angiography in pseudophakic cystoid macular oedema compared to diabetic macular oedema: qualitative and quantitative evaluation of retinal vasculature

2018 ◽  
Vol 102 (12) ◽  
pp. 1684-1690 ◽  
Author(s):  
Riccardo Sacconi ◽  
Eleonora Corbelli ◽  
Adriano Carnevali ◽  
Stefano Mercuri ◽  
Alessandro Rabiolo ◽  
...  
Keyword(s):  
Optical Coherence Tomography ◽  
Macular Oedema ◽  
Optical Coherence Tomography Angiography ◽  
Diabetic Macular Oedema ◽  
Foveal Avascular Zone ◽  
Cystoid Macular Oedema ◽  
Control Group ◽  
Retinal Vasculature ◽  
Ophthalmological Examination ◽  
Optical Coherence

AimsTo describe optical coherence tomography angiography (OCT-A) abnormalities of patients with pseudophakic cystoid macular oedema (PCMO) before and after pharmacological resolution, compared with diabetic macular oedema (DMO) and normal eyes.MethodsIn this retrospective, observational study, 44 eyes (30 patients) were included: 15 eyes (15 patients) affected by PCMO; 14 healthy fellow eyes used as negative control group; 15 eyes (15 age-matched and sex-matched patients) with DMO used as positive control group. All patients underwent a complete ophthalmological examination at baseline, including OCT-A scans of the macula through AngioPlex CIRRUS-5000 (Carl Zeiss Meditec, Dublin, USA). Patients with PCMO and DMO were re-evaluated after the pharmacological resolution of cystoid macular oedema (CMO).ResultsDisruption of parafoveal capillary arcade and cystoid spaces in deep capillary plexus (DCP) were frequent in patients with PCMO and DMO (73% and 100%, 87% and 100%). Capillary abnormalities and non-perfusion greyish areas in DCP were more frequent in DMO (P<0.001 and P=0.014). Patients with PCMO showed a larger foveal avascular zone area in DCP at baseline (P<0.001), which significantly reduced after treatment (P=0.001). Vessel density of full-thickness retina and DCP was reduced in patients with PCMO (P=0.022 and P=0.001), and no changes were observed after treatment. Interestingly, DCP appeared less represented in patients with DMO than PCMO subjects (P=0.001).ConclusionsPatients with PCMO have an impairment of mainly DCP, partially reversible after treatment. Furthermore, we disclosed that different alterations of the retinal vasculature characterise CMO derived from two different diseases, namely PCMO and DMO, and this could be due to their distinct pathophysiology.

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.

Morphological and topographical appearance of microaneurysms on optical coherence tomography angiography

2018 ◽  
Vol 103 (5) ◽  
pp. 630-635 ◽  
Author(s):  
Vivian Schreur ◽  
Artin Domanian ◽  
Bart Liefers ◽  
Freerk G Venhuizen ◽  
B Jeroen Klevering ◽  
...  
Keyword(s):  
Optical Coherence Tomography ◽  
Macular Oedema ◽  
Optical Coherence Tomography Angiography ◽  
Diabetic Macular Oedema ◽  
Optical Coherence ◽  
Retinal Area ◽  
Fundus Fluorescein Angiography ◽  
Morphological Appearance ◽  
Capillary Plexus ◽  
Retinal Microaneurysms

AimsTo investigate retinal microaneurysms in patients with diabetic macular oedema (DME) by optical coherence tomography angiography (OCTA) according to their location and morphology in relationship to their clinical properties, leakage on fundus fluorescein angiography (FFA) and retinal thickening on structural OCT.MethodsOCTA and FFA images of 31 eyes of 24 subjects were graded for the presence of microaneurysms. The topographical and morphological appearance of microaneurysms on OCTA was evaluated and classified. For each microaneurysm, the presence of focal leakage on FFA and associated retinal thickening on OCT was determined.ResultsOf all microaneurysms flagged on FFA, 295 out of 513 (58%) were also visible on OCTA. Microaneurysms with focal leakage and located in a thickened retinal area were more likely to be detected on OCTA than not leaking microaneurysms in non-thickened retinal areas (p=0.001). Most microaneurysms on OCTA were seen in the intermediate (23%) and deep capillary plexus (22%). Of all microaneurysms visualised on OCTA, saccular microaneurysms were detected most often (31%), as opposed to pedunculated microaneurysms (9%). Irregular, fusiform and mixed fusiform/saccular-shaped microaneurysms had the highest likeliness to leak and to be located in thickened retinal areas (p<0.001, p<0.001 and p=0.001).ConclusionsRetinal microaneurysms in DME could be classified topographically and morphologically by OCTA. OCTA detected less microaneurysms than FFA, and this appeared to be dependent on leakage activity and retinal thickening. Morphological appearance of microaneurysms (irregular, fusiform and mixed saccular/fusiform) was associated with increased leakage activity and retinal thickening.

Hyperreflective cystoid spaces in diabetic macular oedema: prevalence and clinical implications

2020 ◽  
pp. bjophthalmol-2020-317191
Author(s):  
Aude Couturier ◽  
Valerie Mane ◽  
Carlo Alessandro Lavia ◽  
Ramin Tadayoni
Keyword(s):  
Macular Oedema ◽  
Optical Coherence Tomography Angiography ◽  
Diabetic Macular Oedema ◽  
Functional Improvement ◽  
Vascular Endothelial ◽  
Hard Exudates ◽  
Corrected Visual Acuity ◽  
The Mean ◽  
Endothelial Growth Factor

AimsTo analyse the prevalence and evolution of hyper-reflective cystoid spaces with decorrelation signal detected using optical coherence tomography angiography (OCTA) in diabetic macular oedema (DMO).MethodsA retrospective study of consecutive eyes with DMO imaged using OCTA over a 1-year period was conducted. All eyes with hyper-reflective cystoid spaces at baseline and at least 3 months of follow-up were included in a longitudinal analysis.ResultsThe prevalence of hyperreflective cystoid spaces with decorrelation signal was of 37% (61/165) in DMO eyes. Hyperreflective foci within hyperreflective cystoid spaces were observed in 85% of eyes. The longitudinal study included 33 eyes (10 observed and 23 treated with intravitreal anti-vascular endothelial growth factor), with a median follow-up of 15 months. The hyperreflective cystoid spaces resolved in 85% of eyes. The mean best-corrected visual acuity remained stable during the follow-up, even in the eyes achieving a resolution of the hyperreflective cystoid spaces. Hard exudates appeared in the area of resolved hyperreflective cystoid spaces in 33% of eyes.ConclusionHyperreflective cystoid spaces detected by OCTA affected more than one-third of the DMO eyes. Their disappearance was not associated with any functional improvement and led to the formation of new hard exudate deposits in about one-third of the eyes.

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