scholarly journals Analysis of Foveal Microvascular Abnormalities in Diabetic Retinopathy Using Optical Coherence Tomography Angiography with Projection Artifact Removal

2018 ◽  
Vol 2018 ◽  
pp. 1-9 ◽  
Author(s):  
Lun Liu ◽  
Jian Gao ◽  
Weili Bao ◽  
Chengyang Hu ◽  
Yajing Xu ◽  
...  
Keyword(s):  
Optical Coherence Tomography ◽  
Diabetic Retinopathy ◽  
Optical Coherence Tomography Angiography ◽  
Vessel Density ◽  
Foveal Avascular Zone ◽  
Optical Coherence ◽  
Artifact Removal ◽  
Significant Difference ◽  
Patients With Diabetes ◽  
Capillary Plexus

Purpose. To analyze foveal microvascular abnormalities in different stages of diabetic retinopathy (DR) using optical coherence tomography angiography (OCTA) with projection artifact removal (PAR). Methods. We analyzed 93 eyes of 59 patients with diabetes—31 with no DR (no DR), 34 with mild to moderate nonproliferative DR (mild DR), and 28 with severe nonproliferative DR to proliferative DR (severe DR)—and 31 age-matched healthy controls. Sections measuring 3 × 3 mm2 centered on the fovea were obtained using OCTA. The area, perimeter, and acircularity index (AI) of the foveal avascular zone (FAZ), vessel density within a 300 μm wide region of the FAZ (FD-300), and parafoveal vessel density in the superficial capillary plexus (SCP) and deep capillary plexus (DCP) were calculated using novel built-in software with PAR. Results. There was no statistically significant difference in the FAZ area (p=0.162). There was a statistically significant difference in the FAZ perimeter (p=0.010) and the AI (p<0.001) between the four groups. There was a correlation between the AI and the increasing severity of DR (p=0.010). Statistically significant decreases of vessel density in the FD-300, SCP, and DCP were observed (all p<0.001). There was a difference in parafoveal vessel density in the DCP between the healthy control eyes and the eyes with diabetes without DR (p=0.027). There was a significant correlation between vessel density and increasing severity of DR (p<0.001). Conclusion. Compared with the FAZ area, AI allows a more helpful quantitative assessment of the changes in the FAZ. Vessel density determined using OCTA with PAR might be a useful parameter indicating the progression of DR. Parafoveal vessel density in the DCP after PAR might be a potential early biomarker of DR before appearance of clinically evident retinopathy and needs further investigation.

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 Reversed Neurovascular Coupling on Optical Coherence Tomography Angiography Is the Earliest Detectable Abnormality before Clinical Diabetic Retinopathy

2020 ◽  
Vol 9 (11) ◽  
pp. 3523
Author(s):  
Yi Stephanie Zhang ◽  
Ilda Mucollari ◽  
Changyow C. Kwan ◽  
Gianna Dingillo ◽  
Jaspreet Amar ◽  
...  
Keyword(s):  
Optical Coherence Tomography ◽  
Diabetic Retinopathy ◽  
Dark Adaptation ◽  
Optical Coherence Tomography Angiography ◽  
Neurovascular Coupling ◽  
Flow Index ◽  
Optical Coherence ◽  
Significant Difference ◽  
Capillary Plexus ◽  
Healthy Eyes

Diabetic retinopathy (DR) has traditionally been viewed as either a microvasculopathy or a neuropathy, though neurovascular coupling deficits have also been reported and could potentially be the earliest derangement in DR. To better understand neurovascular coupling in the diabetic retina, we investigated retinal hemodynamics by optical coherence tomography angiography (OCTA) in individuals with diabetes mellitus (DM) but without DR (DM no DR) and mild non-proliferative DR (mild NPDR) compared to healthy eyes. Using an experimental design to monitor the capillary responses during transition from dark adaptation to light, we examined 19 healthy, 14 DM no DR and 11 mild NPDR individuals. We found that the only structural vascular abnormality in the DM no DR group was increased superficial capillary plexus (SCP) vessel density (VD) compared to healthy eyes, while mild NPDR eyes showed significant vessel loss in the SCP at baseline. There was no significant difference in inner retinal thickness between the groups. During dark adaptation, the deep capillary plexus (DCP) VD was lower in mild NPDR individuals compared to the other two groups, which may leave the photoreceptors more susceptible to ischemia in the dark. When transitioning from dark to ambient light, both diabetic groups showed a qualitative reversal of VD trends in the SCP and middle capillary plexus (MCP), with significantly decreased SCP at 5 min and increased MCP VD at 50 s compared to healthy eyes, which may impede metabolic supply to the inner retina during light adaptation. Mild NPDR eyes also demonstrated DCP dilation at 50 s and 5 min and decreased adjusted flow index at 5 min in light. Our results show altered neurovascular responses in all three macular vascular plexuses in diabetic subjects in the absence of structural neuronal changes on high resolution imaging, suggesting that neurovascular uncoupling may be a key mechanism in the early pathogenesis of DR, well before the clinical appearance of vascular or neuronal loss.

scholarly journals Quantifying the pattern of retinal vascular orientation in diabetic retinopathy using optical coherence tomography angiography

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Yanhui Ma ◽  
Matthew P. Ohr ◽  
Xueliang Pan ◽  
Cynthia J. Roberts
Keyword(s):  
Optical Coherence Tomography ◽  
Diabetic Retinopathy ◽  
Optical Coherence Tomography Angiography ◽  
Preferred Orientation ◽  
Vessel Density ◽  
Optical Coherence ◽  
Vessel Area ◽  
Retinal Microvasculature ◽  
Significant Difference ◽  
Orientation Pattern

AbstractQuantitative imaging using optical coherence tomography angiography (OCTA) could provide objective tools for the detection and characterization of diabetic retinopathy (DR). In this study, an operator combining the second derivative and Gaussian multiscale convolution is applied to identify the retinal orientation at each pixel in the OCTA image. We quantified the pattern of retinal vascular orientation and developed three novel quantitative metrics including vessel preferred orientation, vessel anisotropy, and vessel area. Each of eight 45º sectors of the circular disk centered at the macular region was defined as the region of interest. Significant sectoral differences were observed in the preferred orientation (p < 0.0001) and vessel area (p < 0.0001) in the 34 healthy subjects, whereas vessel anisotropy did not demonstrate a significant difference among the eight sectors (p = 0.054). Differential retinal microvascular orientation patterns were observed between healthy controls (n = 34) and the DR subjects (n = 7). The vessel area characterized from the vascular orientation pattern was shown to be strongly correlated with the traditionally reported vessel density (Pearson R > 0.97, p < 0.0001). With three metrics calculated from the vascular orientation pattern simultaneously and sectorally, our quantitative assessment for retinal microvasculature provides more information than vessel density alone and thereby may enhance the detection of DR. These preliminary results suggest the feasibility and advantage of our vessel orientation-based quantitative approach using OCTA to characterize DR-associated changes in retinal microvasculature.

scholarly journals Macular perfusion density evaluation in constant and intermittent exotropia by means of optical coherence tomography angiography

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Jing Zhai ◽  
Wei Fang ◽  
Xueting Yu ◽  
Xinjie Ye ◽  
Lijie Hou
Keyword(s):  
Optical Coherence Tomography ◽  
Optical Coherence Tomography Angiography ◽  
Cross Sectional Study ◽  
Foveal Avascular Zone ◽  
Optical Coherence ◽  
Intermittent Exotropia ◽  
Cross Sectional ◽  
Significant Difference ◽  
Capillary Plexus ◽  
Perfusion Density

Abstract Background To quantify and compare retinal microvascular features using optical coherence tomography angiography (OCTA) in constant (XT) and intermittent exotropia (IXT). Methods An observational cross-sectional study was conducted from September 2020 to November 2020 at the Affiliated Eye Hospital of Wenzhou Medical University. OCTA examination was performed to evaluate the macular perfusion density of the deep capillary plexus (DCP), superficial capillary plexus (SCP), and foveal avascular zone (FAZ) parameters in XT and IXT patients, and in age-matched controls. The study parameters were analyzed. Results A total of 76 participants, including 16 (21%) XT patients, 24 (32%) IXT patients, and 36 (47%) controls, were recruited. The exodeviation angle was 39.06 ± 10.38 prism degrees (PD) at near and 43.00 ± 9.74 PD at distance in the XT group, and 27.13 ± 18.28 PD at near and 31.04 ± 18.82 PD at distance in the IXT group. The macular perfusion density of the DCP in 6 × 6-mm scans and the SCP in 3 × 3-mm scans were lower in the deviating eyes than in the fixating eyes of XT patients (p < 0.001, p = 0.032, respectively). The macular perfusion density of the DCP in the deviating eyes of XT and IXT patients was significantly lower than that of the controls. There was no significant difference in the FAZ parameters among the groups. Conclusions In XT patients, OCTA revealed lower macular perfusion density in deviating eyes than in fixating eyes and control eyes. IXT patients showed no difference between the two eyes, but the macular perfusion density of the DCP was lower than that of the controls.

scholarly journals Macular and peripapillary vessel density measurement in the evaluation of Non-proliferative Diabetic Retinopathy

2018 ◽  
Author(s):  
Dawei Yang ◽  
Dan Cao ◽  
Honghua Yu ◽  
Xiaohong Yang ◽  
Zhongning Huang ◽  
...  
Keyword(s):  
Optical Coherence Tomography ◽  
Diabetic Retinopathy ◽  
Normal Control ◽  
Optical Coherence Tomography Angiography ◽  
Vessel Density ◽  
Optical Coherence ◽  
Macular Area ◽  
Rnfl Thickness ◽  
Capillary Plexus ◽  
Peripapillary Area

Abstract Purpose: To compare vessel density in macular and peripapillary area between control subjects and patients with non-proliferative diabetic retinopathy (NPDR) using optical coherence tomography angiography (OCTA) and to evaluate the association between RNFL thickness and different stage of diabetic retinopathy. Methods: A total of 170 eyes (normal control, 43; mild NPDR, 43; moderate NPDR, 42; severe NPDR, 42) underwent OCTA imaging. Optical coherence tomography angiographic parameters were vessel densities in superficial capillary plexus (SCP), deep capillary plexus (DCP) in macular area and peripapillary area. Results: The reduction of vessel density of SCP and DCP in macular area, peripapillary area as well as RNFL thickness were correlated with increasing severity of DR. Vessel density of SCP and DCP in macular area, peripapillary area and FD300 in NPDR groups decreased as compared to normal control (P<0.001). Vessel density of DCP shows better ability to identify the severity of DR (sensitivity, and specificity of 88.1%, and 85.2%, respectively) than in FD 300, vessel density of SCP in macular area and peripapillary area Conclusion: Macular and peripapillary vessel density as well as RNFL thickness were significantly decreased in different stage of NPDR compared to normal controls. Vessel density in DCP could be an objective and sensitive indicator for monitoring progression of DR. OCTA might be clinically useful to evaluate microvascular and microstructural alterations in macula and ONH, thus providing a new method to study the course of DR. Key Words: Diabetic retinopathy, optical coherence tomography angiography, vessel density, RNFL thickness, FD 300

scholarly journals Assessment of the retinal vasculature in healthy Chinese preschool children aged 4–6 years old using optical coherence tomography angiography

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Lu Xiang ◽  
Yingming Zhou ◽  
Yanwei Chen ◽  
Siyu Jiang ◽  
Chunli Fei ◽  
...  
Keyword(s):  
Optical Coherence Tomography ◽  
Preschool Children ◽  
Optic Disc ◽  
Optical Coherence Tomography Angiography ◽  
Vessel Density ◽  
Retinal Vasculature ◽  
Optical Coherence ◽  
Significant Difference ◽  
Capillary Plexus ◽  
The Mean

Abstract Purpose To establish normal parameters of macular and optic disc vasculature by optical coherence tomography angiography (OCTA) in healthy preschool children aged 4–6 years old in China. OCTA reflects retinal metabolism and development in children at these ages and could be used clinically and in future studies to aid diagnosis and prediction of retinal abnormalities and developmental stagnation. Methods In this cross-sectional study, we measured foveal, parafoveal, and perifoveal vessel density in the superficial capillary plexus (SCP); the deep capillary plexus (DCP), the foveal avascular zone (FAZ), and the radial capillary peripapillary (RPC) in the optic disc using investigational spectral-domain OCTA. The magnification effect of the FAZ area and microvasculature measurements was corrected by Littman and the modified Bennett formula. Results A total of 242 eyes (116 males and 126 females, 5.31 ± 0.73 years) were recruited for the analysis. The mean macular vessel density was 48.10 ± 2.92% and 48.74 ± 6.51% in the SCP and the DCP, respectively. The RPC vessel density was 47.17 ± 2.52%, 47.99 ± 4.48%, and 48.41 ± 3.07% in the whole image, inside disc, and peripapillary, respectively; and the mean FAZ area was 0.28 ± 0.11 mm2. A significant difference between male and female participants was found in the retinal vasculature (DCP, SCP, and RPC). None of these parameters were significantly different in age (P > 0.05), except that DCP slightly increased with aging. The right and left eyes had good consistency in the parameters of the macula and optic disc. Conclusions Our study establishes the macular and optic disc OCTA reference values in 4- to 6-year-old healthy preschool children. They may be used in longitudinal OCTA studies and clinical applications.

Optical coherence tomography angiography findings of diabetic patients with and without retinopathy

2021 ◽  
pp. 112067212199056
Author(s):  
Emine Temel ◽  
Figen Batıoğlu
Keyword(s):  
Optical Coherence Tomography ◽  
Optical Coherence Tomography Angiography ◽  
Foveal Avascular Zone ◽  
Diabetic Patients ◽  
Optical Coherence ◽  
Significant Difference ◽  
Capillary Plexus ◽  
The Difference ◽  
Healthy Persons ◽  
Group 1

Purpose: To emphasize the importance of optical coherence tomography angiography (OCTA) in the diagnosis and follow-up of diabetic individuals with and without retinopathy. Methods: Retrospective, cross-sectional, observational study of healthy persons and diabetic individuals with and without retinopathy. Area of the foveal avascular zone (FAZ) (mm²), non-perfused areas in the superficial capillary plexus (SCP), mean vessel density (VD) in the SCP, and deep capillary plexus (DCP) were calculated. In eyes with diabetic retinopathy (DR), measurements at baseline, 3rd, 6th, 9th, and 12th months were evaluated. Results: This study conducted on 39 eyes of 23 patients with DR (group 1), 59 eyes of 30 diabetic individuals without DR (group 2), and 51 eyes of 27 healthy persons (group 3). When the mean area of the FAZ at baseline was compared between groups, the difference among groups 1 and 3 ( p < 0.001) and the difference among groups 2 and 3 ( p = 0.001) were statistically significant. There was no significant difference among the measurements of mean area of the FAZ, mean non-perfused area in the SCP, mean VD in SCP, and DCP at baseline, 3rd, 6th, 9th, and 12th months in group 1. Conclusion: OCTA is a developing technology that can detect early microvascular changes in diabetic patients.

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.

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