Does Projection Artifact Removal Improve Visualization of Images in Optical Coherence Tomography Angiography?

2019 ◽  
Vol 3 (5) ◽  
pp. 289-296
Author(s):  
Verena R. Juncal ◽  
Armin Abadeh ◽  
Keyvan Koushan ◽  
Alan R. Berger ◽  
David R. Chow
Keyword(s):  
Optical Coherence Tomography ◽  
Optical Coherence Tomography Angiography ◽  
Optical Coherence ◽  
Artifact Removal ◽  
3 Dimensional ◽  
Face Images ◽  
En Face ◽  
Before And After ◽  
Capillary Plexus ◽  
Superficial Capillary Plexus

Purpose: This study assesses the frequency of projection artifacts in optical coherence tomography angiography (OCTA) en face images and compares images before and after applying a 3-dimensional projection artifact removal (3D-PAR) algorithm. Methods: This is a single-center, retrospective study that included consecutive patients with any underlying diagnosis who had OCTA obtained from January to March 2017. Patients with various retinal diseases and also healthy eyes were included. All participants underwent imaging with a scan area of 3 mm × 3 mm. The 4 default en face slabs were analyzed: superficial capillary plexus (SCP), deep capillary plexus (DCP), outer retina (OR), and choriocapillaris (CC). Images were qualitatively analyzed before and after 3D-PAR by 2 independent graders. Results: None of the SCP images had projection artifact before or after 3D-PAR. Scans of the DCP presented projection artifact in 96.5% of the cases. After 3D-PAR, 14.7% had a complete improvement of projection artifact, 56.5% had a partial improvement, 14.1% were worse, and 14.7% presented no change. In the OR, 2.9% had projection artifact, with a complete improvement after 3D-PAR in 40%, partial improvement in 20%, and no change in 40%. Projection artifact was initially present in 97.6% of the images in the CC. After 3D-PAR, there was a complete improvement in 72.9%, partial improvement in 26.5%, and no change in 0.6%. Choroidal neovascularization (CNV) was detected in 29 eyes (17.1%), and 3D-PAR improved detection of CNV in 12 cases (41.4%). Conclusions: OCTA with 3D-PAR technology minimizes the appearance of projection artifacts in the DCP and CC slabs.

scholarly journals Choroidal vessel density in unilateral hyperopic amblyopia using en-face optical coherence tomography

2020 ◽  
Author(s):  
Syunsuke Araki ◽  
Atsushi Miki ◽  
Katsutoshi Goto ◽  
Tsutomu Yamashita ◽  
Tsuyoshi Yoneda ◽  
...  
Keyword(s):  
Optical Coherence Tomography ◽  
Normal Control ◽  
Structural Changes ◽  
Vascular Density ◽  
Optical Coherence ◽  
Swept Source ◽  
3 Dimensional ◽  
Face Images ◽  
En Face ◽  
Normal Controls

Abstract Background Structural changes of the choroid, such as choroidal thickening, have been indicated in amblyopic eyes with hyperopic anisometropia as compared to fellow or healthy eyes. The purpose of the present study was to investigate choroidal vascular density (CVD) in children with unilateral hyperopic amblyopia.Methods This study included 88 eyes of 44 patients with unilateral amblyopia due to hyperopic anisometropia with or without strabismus and 29 eyes of 29 age-matched normal controls. The CVD of Haller's layer was quantified from en-face images constructed by 3-dimensional swept-source optical coherence tomography images flattened relative to Bruch's membrane. The analysis area was a 3×3-mm square of macula after magnification correction. Relationships between CVD and other parameters [best-corrected visual acuity (BCVA), refractive error and subfoveal choroidal thickness (SFCT)] were investigated, and CVDs were compared between amblyopic, fellow, and normal control eyes.Results Mean CVD was 59.11 ± 0.66% in amblyopic eyes, 59.23 ± 0.81% in fellow eyes, and 59.29 ± 0.74% in normal control eyes. CVD showed a significant positive relationship with SFCT (p=0.004), but no relationships with other parameters. No significant differences in CVD were evident among amblyopic, fellow, and normal control eyes after adjusting for SFCT (p=0.502).Conclusions CVD was unrelated to BCVA, and CVD did not differ significantly among amblyopic, fellow and normal control eyes. These results suggest that the local CVD of Haller's layer is unaffected in unilateral hyperopic amblyopic eyes.

Optical coherence tomography angiography in diabetic patients without diabetic retinopathy

2019 ◽  
Vol 30 (6) ◽  
pp. 1418-1423 ◽  
Author(s):  
Claudio Furino ◽  
Grazia Montrone ◽  
Maria Vittoria Cicinelli ◽  
Stefania Balestra ◽  
Maria Oliva Grassi ◽  
...  
Keyword(s):  
Optical Coherence Tomography ◽  
Diabetic Retinopathy ◽  
Optical Coherence Tomography Angiography ◽  
Vessel Density ◽  
Foveal Avascular Zone ◽  
Diabetic Patients ◽  
Optical Coherence ◽  
Avascular Zone ◽  
Capillary Plexus ◽  
Superficial Capillary Plexus

Purpose: To investigate a subset of diabetic patients without diabetic retinopathy with optical coherence tomography angiography, assessing the differences in macular perfusion between diseased eyes and healthy controls. Methods: Monocentric cross-sectional study, including 86 eyes from 43 diabetic patients with no clinical signs of diabetic retinopathy and 78 eyes from 39 controls. Patients underwent 3.0 × 3.0 mm and 4.5 × 4.5 mm swept-source optical coherence tomography angiography. Vessel density (%), foveal avascular zone area (mm2), and avascular density (%) were provided for the superficial capillary plexus and the deep capillary plexus. Results: The foveal avascular zone area at the superficial capillary plexus was larger in the study group compared to controls, irrespective of the area of the slab considered. A meaningful difference was found in the vessel density at the deep capillary plexus of the 3.0 × 3.0 mm slab (p = 0.03). Almost all the variables considered in the study showed a significant within-subject effect. Age significantly correlated with vessel density of superficial capillary plexus on 4.5 × 4.5 mm in both control and diabetic eyes. Conclusion: Diabetic patients with subclinical diabetic retinopathy feature a larger foveal avascular zone at the superficial capillary plexus compared with controls, as well as relative reduction of the vessel density at the deep capillary plexus. These findings might serve as the basis for screening between normal and diabetic subjects.

scholarly journals Early Retinal Flow Changes after Vitreoretinal Surgery in Idiopathic Epiretinal Membrane Using Swept Source Optical Coherence Tomography Angiography

2019 ◽  
Vol 8 (12) ◽  
pp. 2067 ◽  
Author(s):  
Rodolfo Mastropasqua ◽  
Rossella D’Aloisio ◽  
Pasquale Viggiano ◽  
Enrico Borrelli ◽  
Carla Iafigliola ◽  
...  
Keyword(s):  
Optical Coherence Tomography ◽  
Epiretinal Membrane ◽  
Optical Coherence Tomography Angiography ◽  
Optical Coherence ◽  
Vascular Changes ◽  
Ilm Peeling ◽  
Swept Source ◽  
Idiopathic Epiretinal Membrane ◽  
Capillary Plexus ◽  
Superficial Capillary Plexus

(1) Background: The aim of this observational cross-sectional work was to investigate early retinal vascular changes in patients undergoing idiopathic epiretinal membrane (iERM) surgery using swept source optical coherence tomography angiography (SS-OCTA); (2) Methods: 24 eyes of 24 patients who underwent vitrectomy with internal limiting membrane (ILM) peeling were evaluated pre- and postoperatively using SS-OCTA system (PLEX Elite 9000, Carl Zeiss Meditec Inc., Dublin, CA, USA). For each eye, five 6x6-mm OCTA volume scans were acquired by two observers independently. The en face images of superficial capillary plexus (SCP) were then exported to imageJ and a semi-automated algorithm was used for subsequent quantitative analysis. Perfusion density (PD), vessel length density (VLD), vessel diameter index (VDI) and vessel tortuosity (VT) of SCP were evaluated in both the parafoveal (2.5 mm diameter) and perifoveal areas (5.5 mm diameter); (3) Results: At OCTA analysis statistically significant differences were found between controls and diseased eyes for all parameters in parafoveal and perifoveal regions (p < 0.001; p < 0.05) except for perifoveal VLD. During 6-month follow up, both anatomical/perfusion and functional parameters showed a statistically significant improvement if compared to preoperative values. In detail, at one-month post vitrectomy, VLD and VT significantly changed in parafoveal region (p = 0.043; p = 0.045), while PD and VDI showed a trend of increase in both parafoveal and perifoveal region. At 6 months after surgery, PD, VLD and VT of parafoveal region significantly improved (p = 0.021, p = 0.018, p = 0.047 respectively). (4) Conclusions: SS-OCTA provides a quantitative and qualitative analysis of the superficial capillary plexus allowing for early vascular changes assessment after vitrectomy with iERM and ILM peeling.

scholarly journals Fluorescein Leakage and Optical Coherence Tomography Angiography Features of Microaneurysms in Diabetic Retinopathy

2022 ◽  
Vol 2022 ◽  
pp. 1-9
Author(s):  
Ruoyu Chen ◽  
Anyi Liang ◽  
Jie Yao ◽  
Zicheng Wang ◽  
Yesheng Chen ◽  
...  
Keyword(s):  
Optical Coherence Tomography ◽  
Diabetic Retinopathy ◽  
Fluorescein Angiography ◽  
Detection Rate ◽  
Optical Coherence Tomography Angiography ◽  
Optical Coherence ◽  
Face Images ◽  
Potential Biomarker ◽  
En Face Oct ◽  
En Face

Background and Objective. To correlate optical coherence tomography angiography (OCTA) characteristics of diabetic microaneurysms (MAs) with leakage status on fluorescein angiography (FA). Patients and Methods. 167 MAs from 39 diabetic eyes were analyzed using OCTA and FA simultaneously. The characteristics of MAs on OCTA en face, OCT en face, and OCT B-scan with flow overlay were evaluated and correlated with fluorescein leakage status. Results. Thirty-six, fifty-two, and seventy-nine MAs showed no, mild, and severe leakage on FA, respectively. Most MAs (61.7%) were centered in the inner nuclear layer. Cystoid spaces were observed adjacent to 60 (35.9%) MAs. MAs with severe leakage had a statistically higher flow proportion compared to MAs with no or mild leakage (both P < 0.001 ). Only 112 MAs (67.1%) were visualized in the OCTA en face images, while 165 MAs (98.8%) could be visualized in the OCT en face images. The location of MAs did not associate significantly with FA leakage status. The presence of nearby cystoid spaces and higher flow proportion by OCT B-scan with flow overlay correlated significantly with FA leakage status. Conclusion. The flow proportion of MAs observed on OCT B-scans with flow overlay might be a potential biomarker to identify leaking MAs. A combination of OCT B-scan, OCT en face, and OCTA en face images increased the detection rate of diabetic MAs in a noninvasive way.

scholarly journals Changes In The Macular Vascular Density after Bariatric Surgery Measured by Optical Coherence Tomography Angiography

2021 ◽  
Author(s):  
Malak I ElShazly ◽  
Marwa M Salama ◽  
Kareem Elessawy
Keyword(s):  
Bariatric Surgery ◽  
Optical Coherence Tomography ◽  
Optical Coherence Tomography Angiography ◽  
Macular Thickness ◽  
Vascular Density ◽  
Optical Coherence ◽  
Obese Patients ◽  
Short Term ◽  
Capillary Plexus ◽  
Superficial Capillary Plexus

Abstract Purpose: To evaluate the effect of the weight loss, 3 months after bariatric surgery on the macular thickness and macular vascular density by optical coherence tomography angiography (OCTA).Methods: Forty obese patients were included in this prospective study. Body mass index (BMI), macular thickness (whole, fovea, parafovea and perifovea), macular vascular density (VD) in superficial capillary plexus (whole, fovea, parafovea and perifovea), and macular vascular density in deep capillary plexus (whole, fovea, parafovea and perifovea) were measured before and 3 months after bariatric surgery.Results: The BMI was significantly reduced postoperatively to 43.75±4.4 kg/m2 compared to the preoperative results 55.31±5.1 kg/m2 (p<0.0001). There was significant increase in the macular thickness in the fovea and parafovea postoperatively (p <0.001), but was not significant in the perifovea. There was significant increase in the macular vascular density in the deep capillary plexus postoperatively (p<0.05), but, there was no significant increase in the macular vascular density in the superficial capillary plexus postoperatively (p = 0.4). Significant correlations were detected between the BMI changes and changes in different macular parameters.Conclusion: Bariatric surgery showed significant effect on certain indices in the macular thickness and macular vascular density especially in the deep capillary plexus. Therefore, OCTA is considered a valuable tool to assess the short term changes in the macular microcirculation following significant weight reduction.

scholarly journals Choroidal vessel density in unilateral hyperopic amblyopia using en-face optical coherence tomography

2020 ◽  
Vol 20 (1) ◽  
Author(s):  
Syunsuke Araki ◽  
Atsushi Miki ◽  
Katsutoshi Goto ◽  
Tsutomu Yamashita ◽  
Tsuyoshi Yoneda ◽  
...  
Keyword(s):  
Optical Coherence Tomography ◽  
Normal Control ◽  
Structural Changes ◽  
Vascular Density ◽  
Optical Coherence ◽  
Swept Source ◽  
3 Dimensional ◽  
Face Images ◽  
En Face ◽  
Normal Controls

Abstract Background Structural changes of the choroid, such as choroidal thickening, have been indicated in amblyopic eyes with hyperopic anisometropia as compared to fellow or healthy eyes. The purpose of the present study was to investigate choroidal vascular density (CVD) in children with unilateral hyperopic amblyopia. Methods This study included 88 eyes of 44 patients with unilateral amblyopia due to hyperopic anisometropia with or without strabismus and 29 eyes of 29 age-matched normal controls. The CVD of Haller’s layer was quantified from en-face images constructed by 3-dimensional swept-source optical coherence tomography images flattened relative to Bruch’s membrane. The analysis area was a 3 × 3-mm square of macula after magnification correction. Relationships between CVD and other parameters [best-corrected visual acuity (BCVA), refractive error and subfoveal choroidal thickness (SFCT)] were investigated, and CVDs were compared between amblyopic, fellow, and normal control eyes. Results Mean CVD was 59.11 ± 0.66% in amblyopic eyes, 59.23 ± 0.81% in fellow eyes, and 59.29 ± 0.74% in normal control eyes. CVD showed a significant positive relationship with SFCT (p = 0.004), but no relationships with other parameters. No significant differences in CVD were evident among amblyopic, fellow, and normal control eyes after adjusting for SFCT (p = 0.502). Conclusions CVD was unrelated to BCVA, and CVD did not differ significantly among amblyopic, fellow and normal control eyes. These results suggest that the local CVD of Haller’s layer is unaffected in unilateral hyperopic amblyopic eyes.

scholarly journals Optical Coherence Tomography Angiography Analysis of Retinal and Choroidal Vascular Networks during Acute, Relapsing, and Quiescent Stages of Macular Toxoplasma Retinochoroiditis

2020 ◽  
Vol 2020 ◽  
pp. 1-8
Author(s):  
Georges Azar ◽  
Catherine Favard ◽  
Sawsen Salah ◽  
Antoine Brézin ◽  
Vivien Vasseur ◽  
...  
Keyword(s):  
Optical Coherence Tomography ◽  
Optical Coherence Tomography Angiography ◽  
Capillary Density ◽  
Vascular Network ◽  
Optical Coherence ◽  
Vascular Networks ◽  
Partial Restoration ◽  
Acute Presentation ◽  
Capillary Plexus ◽  
Superficial Capillary Plexus

Purpose. To highlight the advantages of optical coherence tomography angiography (OCTA) in delineating the morphological features of the retinal and choroidal vascular network during acute, relapsing, and quiescent stages of macular toxoplasma retinochoroiditis. Methods. This prospective study included patients presenting with both active and quiescent ocular toxoplasmoses. OCTA was obtained to diagnose and follow the subsequent vascular network changes at diagnosis and six months after acute presentation. Results. Twenty-three eyes of 23 patients were included. In active lesions, OCTA showed extensive, well-delineated areas of intense hyposignal and perifoveal capillary arcade disruption in the parafoveal superficial capillary plexus (pSCP) and less extensive hyposignal in the parafoveal deep capillary plexus (pDCP). Signals of decreased deep capillary density and disorganization were also seen in the choroid. In nonactive lesions, OCTA demonstrated a homogenous and equally attenuated grayish hyposignal of the pSCP and pDCP and a partial restoration of the nonperfused choroidal areas. Conclusion. OCTA is a useful technique for vascular network analysis in toxoplasma retinochoroiditis. It allows the visualization of the different network changes and behaviors during the different stages of the infection.

Plexus-specific effect of flicker-light stimulation on the retinal microvasculature assessed with optical coherence tomography angiography

2021 ◽  
Vol 320 (1) ◽  
pp. H23-H28
Author(s):  
Martin Kallab ◽  
Nikolaus Hommer ◽  
Bingyao Tan ◽  
Martin Pfister ◽  
Andreas Schlatter ◽  
...  
Keyword(s):  
Optical Coherence Tomography ◽  
Optical Coherence Tomography Angiography ◽  
Specific Effect ◽  
Optical Coherence ◽  
Specific Mechanism ◽  
Physiological Importance ◽  
Retinal Microvasculature ◽  
Capillary Plexus ◽  
Flicker Stimulation ◽  
Superficial Capillary Plexus

We present vessel density alterations in response to flicker stimulation using optical coherence tomography angiography and identified the superficial capillary plexus as the layer with the most pronounced effect. This points out the physiological importance of the microvasculature in mediating functional hyperemia and suggests a fine-tuned plexus-specific mechanism to meet cellular metabolic demands.

Evaluation of pseudophakic cystoid macular edema using optical coherence tomography angiography

2017 ◽  
Vol 28 (2) ◽  
pp. 234-240 ◽  
Author(s):  
Rita Serra ◽  
Alexandre Sellam ◽  
Florence Coscas ◽  
Elsa Bruyère ◽  
André Sieiro ◽  
...  
Keyword(s):  
Optical Coherence Tomography ◽  
Cystoid Macular Edema ◽  
Optical Coherence Tomography Angiography ◽  
Face Image ◽  
Vascular Density ◽  
Optical Coherence ◽  
En Face ◽  
Capillary Plexus ◽  
Healthy Eyes ◽  
Sd Oct

Purpose: To compare the optical coherence tomography angiography (OCT-A) findings of the superficial capillary plexus (SCP) and deep capillary plexus (DCP) in eyes with pseudophakic cystoid macular edema (PCME) with those of fluorescein angiography (FA) and spectral-domain optical coherence tomography (SD-OCT) and to compare PCME vascular density values of the SCP and DCP with those of healthy eyes. Methods: In this retrospective observational study, 13 eyes (12 patients) with PCME underwent comprehensive ophthalmologic examinations including visual acuity, FA, SD-OCT, and OCT-A. The vascular density of the SCP and DCP were measured using AngioAnalytics software in all PCME eyes and compared with 46 healthy eyes of 25 subjects. Results: In patients with PCME, at the level of SCP, the mean vascular density in the whole en face image was 44.48 ± 3.61% while it was 50.27 ± 5.30% at the level of the DCP. In contrast, the vascular density in the whole en face image was 50.35 ± 3.22 at the level of SCP while it was 56.15 ± 3.28 at the level of DCP in 46 healthy eyes of 25 subjects. The vascular density of patients with PCME was significantly lower than in healthy subjects at the SCP (p<0.0001) and at the DCP (p<0.0001). Conclusion: We report the OCT-A appearance of PCME and vascular density map with values that can be easily interpreted for quantitative evaluation of retina perfusion status using OCT-A. This approach might be the first step in helping us fully understand the pathophysiologic mechanisms underlying PCME.

scholarly journals Microaneurysms visualisation using five different optical coherence tomography angiography devices compared to fluorescein angiography

2020 ◽  
pp. bjophthalmol-2020-316817 ◽  
Author(s):  
Salvatore Parrulli ◽  
Federico Corvi ◽  
Mariano Cozzi ◽  
Davide Monteduro ◽  
Federico Zicarelli ◽  
...  
Keyword(s):  
Optical Coherence Tomography ◽  
Fluorescein Angiography ◽  
Optical Coherence Tomography Angiography ◽  
Imaging Modality ◽  
Optical Coherence ◽  
Capillary Plexus ◽  
Retinal Microaneurysms ◽  
Scan Pattern ◽  
Superficial Capillary Plexus ◽  
Higher Sensitivity

BackgroundTo compare fluorescein angiography (FA) and five different optical coherence tomography angiography (OCTA) devices and to test their reproducibility in the evaluation of retinal microaneurysms (MAs) secondary to diabetic retinopathy (DR).MethodsOn the same day, patients with DR were imaged with FA and five OCTA devices: prototype Spectralis OCTA, prototype PlexElite, RTVue XR Avanti, AngioPlex and DRI OCT Triton. For all OCTA devices, a 3×3 volume scan pattern was performed. MAs were evaluated for the superficial capillary plexus (SCP) and deep capillary plexus (DCP).ResultsTwenty eyes of 15 patients with DR were included. FA counted a significantly higher number of MAs compared to OCTA devices. Spectralis OCTA obtained a significantly higher number of MAs compared to PlexElite, RTVue XR Avanti, AngioPlex and DRI OCT Triton (p<0.0001). PlexElite and AngioPlex showed a greater number of MAs in the SCP, Spectralis OCTA, RTVue XR Avanti and DRI OCT Triton in the DCP. Higher sensitivity (43.3%) but lowest specificity (54.4%) was observed for Spectralis OCTA compared to other devices. The higher specificity (78.5%) and positive predictive value (83.3%) were observed for DRI OCT Triton.ConclusionsFA remains the best imaging modality to visualise retinal MAs. Spectralis OCTA was able to detect more MAs compared to other devices, likely due to the higher number of B-scans in the scanned area as well as due to the higher number of repeated B-scans. The high variability between OCTA devices should be taken into account for future clinical trials as in clinical practice.

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