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 ◽  
...  

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.

2018 ◽  
Vol 2 (6) ◽  
pp. 343-350
Author(s):  
Katsuya Suzuki ◽  
Miho Nozaki ◽  
Noriaki Takase ◽  
Aki Kato ◽  
Hiroshi Morita ◽  
...  

Purpose: The purpose of this article is to evaluate long-term change of the foveal avascular zone (FAZ) area in diabetic eyes using optical coherence tomography angiography (OCTA) (AngioVue, Avanti OCT, Optovue). Methods: A retrospective chart review was conducted of patients who had undergone OCTA fundus examinations with at least 12 months of follow-up. Eyes with previous laser photocoagulation and antivascular endothelial growth factor treatments were excluded. ImageJ software was used to evaluate the FAZ area in the superficial capillary plexus (SCP) and deep capillary plexus (DCP). Results: Forty eyes were analyzed in this study and divided into 3 groups: healthy controls (13 eyes), diabetic patients without diabetic retinopathy (DR) (14 eyes), and diabetic patients with DR (13 eyes). During the 22 months of follow-up, the FAZ area of eyes with DR in the DCP enlarged from 0.64 ± 0.20 mm2 to 0.70 ± 0.20 mm2 ( P = .021), which was a 10.1% increase from baseline (5.1% per year). No significant changes were observed during the study period for FAZ areas in the DCP of controls and diabetic patients without DR. Enlargement of FAZ in the DCP was significantly greater in eyes with DR progression vs those without progression (19.2% and 1.2%, respectively, P = .013). Conclusions: Our data suggest FAZ enlargement in the DCP is associated with DR progression. Assessment of the FAZ by OCTA might be useful for the evaluation of microcirculation abnormalities in DR and the onset of DR progression.


2020 ◽  
Vol 30 (3) ◽  
pp. 600-607
Author(s):  
Elif Güler Kazancı ◽  
Muhammet Furkan Korkmaz ◽  
Mehmet Erol Can

Purpose: The purpose was to evaluate retinal vascular parameters by optical coherence tomography angiography in β-thalassemia major patients. Methods: Thirty-three patients with β-thalassemia major (study group) and 29 healthy children (control group) were enrolled in the study. All subjects underwent a complete ocular examination. The mean foveal avascular zone, non-flow area, foveal avascular zone perimeter, acircularity index of foveal avascular zone, foveal density, the superficial capillary plexus, and deep capillary plexus were scanned using 6 × 6 mm optical coherence tomography angiography scans centered on the macula. Superficial capillary plexus and deep capillary plexus were also scanned centered on the optic disk. We collected data on histories of patients, and hemoglobin and ferritin were also studied from both groups. Results: The mean age was 13.85 ± 4.69 years (range: 4–21 years) in β-thalassemia major group and 12.59 ± 3.66 years (range: 6–18 years) in the control group. The mean foveal avascular zone value was 0.265 ± 0.11 mm2 in the study group and 0.296 ± 0.12 mm2 in the control group. The mean non-flow area value was 0.468 ± 0.12 mm2 in the study group and 0.479 ± 0.14 mm2 in the control group ( p > 0.05). Differences in the mean values for foveal density and acircularity index were statistically significant between the study group and control group ( p < 0.05, p = 0.026, and p = 0.026, respectively). Superficial capillary plexus and deep capillary plexus were not a significant difference between the study and control groups in 6 × 6 mm scans on macula and 4.5 × 4.5 mm scans on optic disk area ( p > 0.05). Acircularity index was negatively correlated ( r = −0.292, p = 0.026), and foveal density was positively correlated with hemoglobin ( r = 0.292, p = 0.026). Conclusion: By using optical coherence tomography angiography, we detected foveal microvascular changes in young β-thalassemia patients before significant ocular anomalies development.


Author(s):  
NAGİHAN UĞURLU ◽  
AYŞE GÜZİN TAŞLIPINAR UZEL ◽  
AHMET ŞENGÜN ◽  
FATMA YÜLEK ◽  
DEMET ÖZDAŞ ◽  
...  

Aim: The aim of the current study was to evaluate the correlation between the integrity of the outer retinal layers on optical coherence tomography (OCT) and objective parameters of retinal microvascular perfusion on optical coherence tomography angiography (OCTA). Method: 105 eyes of 54 diabetic patients were included in to the study. Integrity of the outer retinal layers including the external limiting membrane (ELM), ellipsoid zone (EZ), and interdigitation zone (IZ) were assessed by spectral-domain optical coherence tomography (SD-OCT). The foveal avascular zone (FAZ) area and vessel density (VD) measurements in the superficial capillary plexus (SCP) and deep capillary plexus (DCP) in all the Early Treatment Diabetic Retinopathy Study (ETDRS) sectors were evaluated by OCTA. Association between the quantitative measurement of the foveal avascular zone and retinal vessel density measurements and outer retinal disruptions were evaluated. Results: FAZ area was correlated with outer retinal layer disruption at both in the superficial plexus (r = 0.244, 0.228, 0.212, p = 0.013, 0.02, 0.031 for the ELM, EZ and IZ respectively) and deep capillary plexus (r = 0.298, 0.234, 0.197, p = 0.002, 0.019, 0.048 for the ELM, EZ and IZ respectively). A significant relationship was also found between the VD measurements in the SCP and DCP in ETDRS sectors and the outer retinal layers disruption. Conclusion: The result of the current study shows a significant relationship between the quantitative OCTA parameters and the integrity of the outer retinal layers and. This finding reveals a correlation between retinal capillary nonperfusion and outer retinal disruption in eyes with diabetic retinopathy. Key Words: Outer retinal disruption, external limiting membrane, ellipsoid zone, interdigitation zone, foveal avascular zone, superficial capillary plexus, deep capillary plexus, optical coherence tomography angiography


2018 ◽  
Vol 2018 ◽  
pp. 1-9 ◽  
Author(s):  
Lun Liu ◽  
Jian Gao ◽  
Weili Bao ◽  
Chengyang Hu ◽  
Yajing Xu ◽  
...  

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.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Reza Mirshahi ◽  
Pasha Anvari ◽  
Hamid Riazi-Esfahani ◽  
Mahsa Sardarinia ◽  
Masood Naseripour ◽  
...  

AbstractThe purpose of this study was to introduce a new deep learning (DL) model for segmentation of the fovea avascular zone (FAZ) in en face optical coherence tomography angiography (OCTA) and compare the results with those of the device’s built-in software and manual measurements in healthy subjects and diabetic patients. In this retrospective study, FAZ borders were delineated in the inner retinal slab of 3 × 3 enface OCTA images of 131 eyes of 88 diabetic patients and 32 eyes of 18 healthy subjects. To train a deep convolutional neural network (CNN) model, 126 enface OCTA images (104 eyes with diabetic retinopathy and 22 normal eyes) were used as training/validation dataset. Then, the accuracy of the model was evaluated using a dataset consisting of OCTA images of 10 normal eyes and 27 eyes with diabetic retinopathy. The CNN model was based on Detectron2, an open-source modular object detection library. In addition, automated FAZ measurements were conducted using the device’s built-in commercial software, and manual FAZ delineation was performed using ImageJ software. Bland–Altman analysis was used to show 95% limit of agreement (95% LoA) between different methods. The mean dice similarity coefficient of the DL model was 0.94 ± 0.04 in the testing dataset. There was excellent agreement between automated, DL model and manual measurements of FAZ in healthy subjects (95% LoA of − 0.005 to 0.026 mm2 between automated and manual measurement and 0.000 to 0.009 mm2 between DL and manual FAZ area). In diabetic eyes, the agreement between DL and manual measurements was excellent (95% LoA of − 0.063 to 0.095), however, there was a poor agreement between the automated and manual method (95% LoA of − 0.186 to 0.331). The presence of diabetic macular edema and intraretinal cysts at the fovea were associated with erroneous FAZ measurements by the device’s built-in software. In conclusion, the DL model showed an excellent accuracy in detection of FAZ border in enfaces OCTA images of both diabetic patients and healthy subjects. The DL and manual measurements outperformed the automated measurements of the built-in software.


2021 ◽  
Vol 14 (5) ◽  
pp. e240208
Author(s):  
Hana A Mansour ◽  
Sami Uwaydat ◽  
Muhamad H Yunis ◽  
Ahmad M Mansour

Optical coherence tomography angiography imaging in two patients with oculocutaneous albinism, one with severe nystagmus, showed persistence of both the superficial and the deep retinal capillary plexus adding another vascular feature to the foveal hypoplasia.


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