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Background: High myopia represents a health issue and leads to the development of complications that threaten vision. The study of macular changes in high myopia patients has undergone great advances with updated technology via new spectral optical coherence tomography (OCT) and Optical coherence tomography angiography (OCTA). Most of related studies have focused on the adults and additional studies need to investigate macular changes in children and adolescents. This study aimed to evaluate the changes in the macular structure by OCT and the macular vessel density in high myopia in children and adolescents by OCTA. Methods: A cross-sectional comparative study. The population was divided into two groups: group 1 (4–11 years) and group 2 (12–18 years). The results were comparable to those of control study of the same age group. The two high myopia groups and the control groups were examined by macular OCT and OCTA to evaluate macular thickness and vessel density in the superficial and deep capillary plexuses. Results: OCT measurements of patients in group 1 revealed that central macular thickness was significantly lower in high myopia group than in the control group and measured 220.91 ± 27.87 μm and 258.23 ± 17.26 μm, respectively, (P < 0.0001). However, in group 2 the central macular thickness in the high myopia group and control group was 236.32 ± 27.76 μm and 247.09 ± 16.81 μm respectively, and the difference was not statistically significant (P = 0.09). The parafoveal macular thickness and the perifoveal macular quadrants thickness were significantly lower in high myopic children and high myopic adolescents (P < 0.0001) than age matched controls. The parafoveal and perifoveal vessel densities in the superficial and deep capillary plexuses were lower in the high myopia groups than in the age-matched controls in both groups with a few segment exceptions in group 1. The FAZ was significantly wider in group 1 than in the age-matched emmetropes (P = 0.02). The FAZ was wider in group 2 than controls, but the difference was not statistically significant, (P = 0.75). Conclusion: High myopic children and adolescents have thinner macular thickness than comparable age-matched emmetropes and have less vessel density in superficial and deep capillary plexuses with a wider FAZ. [ABSTRACT FROM AUTHOR]

Background: To compare the microvascular features of different subtypes of diabetic macular edema (DME) by optical coherence tomography angiography (OCTA). Methods: A cross-sectional study including treatment-naive patients with DME. Eyes were divided according to optical coherence tomography determined morphology into two groups: cystoid macular edema (CME) and diffuse retinal thickening (DRT), with further subdivision according to the presence of subretinal fluid. All patients underwent 3 × 3 and 6 × 6 mm OCTA scans of the macula to compare the foveal avascular zone (FAZ) area, vascular density (VD) of the superficial (SCP) and deep (DCP) capillary plexus and choriocapillaris flow (CF). Laboratory findings (HbA1C and triglyceride levels) were also correlated with the OCTA findings. Results: The study included 52 eyes, 27 had CME and 25 had DRT. There were no significant differences between the VD of the SCP (p = 0.684) and DCP (p = 0.437), FAZ of SCP (p = 0.574), FAZ of DCP (p = 0.563) and CF (p = 0.311). Linear regression analysis revealed that DME morphology was the strongest predictor for BCVA. Other significant predictors included HbA1C and triglyceride levels. Conclusion: The morphology of DME, irrespective of SRF, was most significantly correlated with BCVA in treatment-naive patients and CME subtype could be an independent predictor of poor BCVA in patients with DME. [ABSTRACT FROM AUTHOR]

Background: To evaluate the changes in macular superficial retinal vessel density and their relation with visual acuity in thyroid-associated ophthalmopathy (TAO) patients with different severity. Methods: This cross-sectional observational study included 70 TAO patients and 70 healthy controls. Only data from the right eyes were analyzed. TAO patients were divided into 7 subgroups according to the NOSPECS score. Foveal avascular zone (FAZ), vascular density (VD), and perfusion density (PD) of macular 1 mm diameter and 6 mm diameter areas were measured by optical coherence tomography angiography (OCTA). Results: In TAO patients, significant increases were found in macular and foveal vascular densities (FVD) and perfusion densities (FPD) while a significant decrease was found in the FAZ area when compared with the control group (p < 0.05). Spearman correlation analysis and multiple linear regression analysis showed that TAO severity grade was negatively correlated with FVD (β = -1.150, p = 0.032), FPD (β = -0.024, p = 0.042), MVD (β = -0.583, p = 0.020) and MPD (β = -0.011, p = 0.010). Clinical activity score (CAS) score showed positive correlation with FVD (β = 0.794, p = 0.035) and FPD(β = 0.017, p = 0.041). FVD (β = -0.009, p = 0.033), MVD(β = -0.034, p < 0.001), FPD(β = -0.416, p = 0.039) and MPD(β = -2.428, p < 0.001) all showed negative correlation with best corrected visual acuity (BCVA). Conclusions: There was an overall increase in superficial macular blood flow in TAO patients compared with healthy controls and the blood flow decreased as TAO got worse. Superficial macular flow density was negatively correlated with BCVA. [ABSTRACT FROM AUTHOR]

Background: To analyze the changes in foveal avascular zone (FAZ) area, perimeter, and circularity in the superficial (SCP) and deep (DCP) capillary plexuses in eyes with diabetic macular edema (DME) treated with intravitreal anti-VEGF using optical coherence tomography angiography (OCTA). Methods: This prospective observational study included 56 eyes from 32 patients with DME that received intravitreal anti-VEGF. OCTA images were obtained at baseline and 1, 3, and 6 months of follow-up. The outcome measures were FAZ area, perimeter, and circularity in both the SCP and DCP, as well as central subfield thickness (CST) and best-corrected visual acuity (BCVA). Results: The mean number of intravitreal anti-VEGF injections received during the observation period was 4.60 ± 0.82 (range: 3–6). The FAZ area, perimeter, and circularity were statistically unchanged at all observation points in both the SCP (p = 0.772, p = 0.405, p = 0.157, respectively) and the DCP (p = 0.620, p = 0.769, p = 0.481, respectively). Despite having no change in the FAZ parameters, there was still a statistically significant decrease in CST (p < 0.001) as well as a statistically significant increase in BCVA (p = 0.004) during the observation period. Conclusions: The FAZ area, perimeter, and circularity in the SCP and DCP as measured by OCTA remained stable during the first 6 months of intravitreal anti-VEGF therapy in eyes with DME. While there were no significant changes in the FAZ, treatment with intravitreal anti-VEGF still resulted in decreased CST and improved BCVA. [ABSTRACT FROM AUTHOR]

This cross-sectional study aimed to quantitatively analyze the optical coherence tomography angiography (OCTA) images using MATLAB-based software and evaluate the initial changes in macular vascular density and the distortion of the foveal avascular zone (FAZ), before the clinical appearance of diabetic retinopathy. For this purpose, 21 diabetic patients without any clinical features indicating DR, and 21 healthy individuals matched with patients based on their demographic characteristics were included. Macular thickness, macular vascular density, and morphological changes of FAZ were assessed using OCTA. The diagnostic ability of morphological parameters was evaluated by receiver operating curve analysis. The intraclass correlation coefficient (ICCC) index was used to check the consistency of the extracted values. There was no significant difference in age, gender, LogMAR visual acuity, spherical equivalent, and intra-ocular pressure amongst patients and controls. No correlation was found between age and the FAZ area as well as vascular density. The vascular structure of the superficial layer showed FAZ enlargement, reduced vascular density in the macular area, and significant deviations of FAZ shape parameters (convexity and Frequency Domain Irregularity) in patients compared with healthy individuals. Measurements were highly correlated between separate imaging sessions with ICCC of over 0.85 for all parameters. The represented data suggests that radiomics parameters can be applied as both an early screening tool and guidance for better follow-up of diabetic patients who have not had any sign of DR in fundoscopic exams. [ABSTRACT FROM AUTHOR]

Backgro: To assess the microvascular changes in the macular region and the foveal avascular zone (FAZ) area in participants with white matter hyperintensities (WMHs) using swept source optical coherence tomography angiography (SS OCTA).Methods: This cross-sectional study included a total of 23 WMH participants (45 eyes) and 20 age-matched healthy participants (40 eyes). SS OCTA (VG200; SVision Imaging, Ltd., Luoyang, China) was used to assess the retinal vessel density (VD) and the FAZ area. VD was measured in the superficial vascular plexus (SVP), intermediate capillary plexus (ICP) and deep capillary plexus (DCP) within a 6 × 6-mm scan centred on the macula using a 5-mm Macula circle. The FAZ area was automatically measured on the inner retina layer within a 3 × 3-mm scan in the macular region.Results: There was no significant difference in VD in the SVP between the two groups. However, VD in both the ICP and DCP was significantly decreased in WMH participants (P = 0.028, P = 0.016). The FAZ area was significantly enlarged in WMH participants (P = 0.030). The signal quality was significantly lower in WMH participants (P < 0.001).Conclusions: This study suggested that WMH participants have retinal microvascular and foveal avascular zone area changes compared with healthy controls. Further longitudinal studies with larger sample sizes are warranted to identify the value of our findings in the early evaluation of WMHs. [ABSTRACT FROM AUTHOR]

Background: To represent choroidal thickness (CT) and choroidal volume (CV) databases in diabetic retinopathy (DR) patients and healthy control participants using optical coherence tomography (OCT) and enhanced depth imaging OCT (EDI-OCT). No study had evaluated CT at all main stages of diabetic retinopathy in a single study.Methods: The study included 176 eyes from 93 patients (39-80 years old; 42% females) who were divided into three groups based on DR severity and normal control group: 39 eyes no DR, 64 eyes NPDR, 33 eyes PDR, and 40 eyes normal control. The CT and CV were measured and statistically analyzed. Intra-observer and inter-observer coefficients of repeatability were calculated.Results: Subfoveal CT showed persistent thinning from normal group (322.50 ± 69.24) to no-diabetic retinopathy (NDR, 308.33 ± 74.45) to nonproliferative diabetic retinopathy (NPDR, 283.45 ± 56.50) group and then thickening as the patient progressed to proliferative diabetic retinopathy (PDR, 295.17 ± 95.69) (P = 0.087). A significant difference was found between the control group and the NDR, NPDR, and PDR groups in nearly all CT and CV of Early Treatment Diabetic Retinopathy Study macular subfields. Fasting blood sugar (FBS = 189.08 ± 51.3 mg/dl) and diabetes mellitus (DM) duration (13.6 ± 6.5 years) had no noticeable effect on CT. In patients with diabetes, the best-corrected visual acuity (BCVA), diabetic macular edema (DME), and foveal avascular zone (FAZ) were not affected by CT and CV.Conclusions: The choroidal thickness decreases from the early stages of diabetic retinopathy up to the NPDR stage, with a subsequent modest rise in CT during the PDR stage. There was no correlation between FBS, diabetes duration, BCVA, DME, and FAZ, and CT. [ABSTRACT FROM AUTHOR]

Background: This study aimed at defining the variance of vessel density (VD) characteristics in the macula of children with normal eyes. Methods: This was a cross-sectional study in which subjects with normal eyes aged 3–18 years were enrolled. The macula was scanned by optical coherence tomography angiography (OCTA). Four age groups as under 7 years, 7–10 years, 11–14 years and more than 14 years of age were defined. The influences of age, gender, and body mass index on VD were analyzed. Results: A total of 108 normal eyes from 54 participants with a mean age of 10.9 years were enrolled in the study. At the superficial and deep retina capillary plexus (SCP and DCP) and choriocapillaris (CC), respectively, the mean VD of the fovea was 20.10%, 36.99%, and 75.67%; at parafovea, these measurements were 53.12%, 55.81%, and 69.76%; and at perifovea, these measures were 51.38%, 52.46%, and 73.47%. The median foveal avascular zone (FAZ) was 0.30 mm2. No significant differences between superior-hemi VD and inferior-hemi VD were found in the studied plexuses. The VD at parafovea and perifovea CC differed significantly between groups. There was no variation in VD of macular retina and CC between eyes or sex. FAZ areas were different between genders. Conclusions: No difference between eyes and genders in the retina and CC VD of macular area was noted. FAZ area was larger in male. Even though this is not a longitudinal study, it may provide us with hints about macular vascular development during puberty and clinical implications of OCTA in children. [ABSTRACT FROM AUTHOR]

Background: One of the major side effects of Hydroxychloroquine (HCQ) is retinopathy. The aim of this study was to evaluate the Optical coherence tomography angiography (OCTA) parameters in a group of patients who have Hydroxychloroquine-induced retinopathy based on Multifocal electroretinography (mfERG) with a group who do not have retinopathy.Method: This is a Cross-Sectional Study. In this study, patients with Rheumatoid arthritis (RA) or Systemic lupus erythematosus (SLE) who had been taking Hydroxychloroquine for at least 7 years were included. MfERG and OCTA imaging were performed for all patients. Patients were divided into Normal mfERG and Abnormal mfERG groups based on mfERG results. OCTA parameters were studied in these two groups.Result: Sixty-one patients (61 eyes) were included. Forty-one patients had SLE and 20 patients had RA. Forty patients (66.7%) had Abnormal mfERG. The mean vascular density (VD) in Superficial capillary plexus (SCP) layer was not significantly different between Normal mfERG and Abnormal mfERG groups (P-Value> 0.05). Mean VD in SCP layer was not significantly different between Normal mfERG and Abnormal mfERG groups (P-Value> 0.05). In RA subgroup, mean VD in SCP layer in PeriFovea region in Abnormal mfERG group was significantly lower than normal group (P-Value < 0.05). Mean VD in deep capillary plexus (DCP) layer in Whole Image, Superior Hemi, Inferior Hemi, PeriFovea area in Abnormal mfERG group was significantly lower than normal group (P-Value < 0.05). This discrepancy was also observed in the RA subgroup but not in the SLE subgroup. The mean of none of the parameters of foveal avascular zone (FAZ) (mm2), Flow Area of Outer Retina (mm2) and Flow Area of Choriocapillaris (mm2) were not statistically significant between the groups Abnormal mfERG and Normal mfERG. (p-value> 0.05).Conclusion: VD in the DCP layer decreased in abnormal mfERG patients compared to patients with normal mfERG. But it seems that VD in SCP layer, FAZ Area and Flow Area are similar in both groups. OCTA may be used as a non-invasive tool in the diagnosis of early stages of HCQ-induced retinopathy, especially in RA patients, but further studies are needed. [ABSTRACT FROM AUTHOR]

Background: To evaluate the reliability of foveal avascular zone (FAZ) area measurements using optical coherence tomography angiography (OCTA) in eyes with retinal vein occlusion (RVO). Methods: Twenty-five OCTA exams of patients with RVO were evaluated retrospectively. Three examiners performed manual measurements of the FAZ, and interrater and intrarater reliability were obtained. Results: The intraclass correlation coefficient (ICC) for interrater reliability for individual measurements was 0.62 (moderate) with a 95% confidence interval (CI) of 0.40 to 0.79 (p < 0.001). The ICC (95% CI) for intrarater reliability was 0.92 (0.82 to 0.96) for rater A, 0.96 (0.91 to 0.98) for B, and 0.88 (0.76 to 0.94) for C (p < 0.001). In all subanalyses including presence of edema and type of occlusion, interrater reliability was poor/moderate, and intrarater reliability was good/excellent. Conclusion: The FAZ varies significantly among eyes with RVO, so measurements obtained using OCTA should be analyzed with caution due to the moderate level of reliability among different examiners. [ABSTRACT FROM AUTHOR]

Background: Optical coherence tomography angiography (OCTA) is a non-invasive tool for imaging and quantifying the retinal and choroidal vasculature as well as perfusion state in healthy eyes. Choroidal perfusion is subject to diurnal variation, showing lowest perfusion in the morning and highest in the afternoon. In this index study, OCTA was used to investigate diurnal changes of the retinal perfusion in healthy adult eyes and to identify impacting factors since retinal perfusion is known to be mainly determined by autoregulatory mechanisms. Methods: A prospective study was conducted on healthy volunteers, each of whom underwent repeated measurements of mean arterial pressure (MAP), intraocular pressure (IOP), macular volume (MV), subfoveal choroidal thickness (SFCT), foveal avascular zone (FAZ) and retinal perfusion of the superficial capillary plexus (SCP), deep capillary plexus (DCP) and full retina (FR) slab at 7 a.m. and 4 p.m. Possible influence of MAP or IOP on the retinal perfusion was evaluated. Results: A total of 22 eyes of 22 participants (mean age 55.91 ± 14.84) were analysed. Significant diurnal changes from 7 a.m. to 4 p.m. were observed for MAP (p < 0.001) and SFCT (p = 0.017). The perfusion of SCP, DCP and FR as well as the size of the FAZ and the MV did not show significant fluctuation during the day. No significant correlation between MAP or IOP and retinal perfusion values were detectable. Conclusion: OCTA-based analysis of the retina in healthy adults demonstrated a steady perfusion of both plexus during the day, independently of changes in MAP. These findings support the theory of autoregulatory mechanisms of the retinal blood flow. [ABSTRACT FROM AUTHOR]

Background: The traditional view is that there are no vessels in the foveal avascular zone. The two cases we report show microvessels crossing the foveal avascular zone.Case Presentation: A man and a woman, both 25 years old, were both incidentally found on optical coherence tomography angiography (OCTA) to have unilateral aberrant microvessels crossing the foveal avascular zone in their left eyes. Visual acuity was preserved in both patients. The vessel density (VD) and perfusion density (PD) of the eyes with the aberrant microvessels were all higher than those of the contralateral eyes. Nevertheless, measurements of foveal avascular zone (FAZ) dimensions, including its area, perimeter and circularity, were smaller in the left eyes than in the right eyes. No complications were recorded.Conclusions: To date, aberrant microvessels crossing the foveal avascular zone have not been found to impair visual function. OCTA is a non-invasive and quick method that does not require dilation or the use of fluorescein dye. It is a reliable tool for the detection of aberrant microvessels crossing the foveal avascular zone. [ABSTRACT FROM AUTHOR]

Background: To evaluate changes of microvascular network of macular and peripapillary regions and to provide a quantitative measurement of foveal avascular zone (FAZ) in unilateral BRVO patients.Methods: Forty-seven unilateral BRVO patients and forty-seven normal controls were enrolled. A 3*3 mm scan centered on fovea followed by a 4.5*4.5 mm scan centered on optic nerve head (ONH) were obtained in BRVO eyes, fellow eyes and control eyes of each individual using OCTA (Optovue Inc., Fremont, CA, USA). Vessel density (VD) in superficial (SVC) and deep vascular complex (DVC) of macula and radial peripapillary capillary (RPC) were automatically calculated. Parameters of FAZ region including size, perimeter, acircularity index (AI) and foveal vessel density 300 (FD-300) were measured.Results: VDs of SCV and DVC were significantly lower, especially in affected regions, in BRVO eyes compared with fellow eyes (P < 0.05). BRVO affected eyes has larger FAZ size, FAZ perimeter, AI and lower FD-300 compared with fellow eyes (all P < 0.05). VD of SVC and FD-300 were lower in fellow eyes compared with normal control eyes (P < 0.05). The average vessel density in whole area and peripapillary area in BRVO eyes were significantly lower compared with fellow eyes (P < 0.05). VD of inside disc in fellow eyes was lower than normal eyes (P < 0.05).Conclusions: OCTA provided quantitative information of vascular changes in BRVO. FAZ in BRVO eyes showed significant morphological alterations and decreases of VD in surrounding area. Decreases of VD existed not only in SVC and DVC in macular region but also in RPCs in BRVO eyes. Unaffected eyes of unilateral BRVO showed vascular abnormalities in superficial retinal layer, peri-FAZ area and also peripapillary regions. [ABSTRACT FROM AUTHOR]

Background: To investigate, using optical coherence tomography angiography (OCT-A), changes in perfusion density and in the foveal avascular zone (FAZ) in eyes with idiopathic vitreomacular traction (VMT) after ocriplasmin injection.Methods: In this pilot study, we enrolled sixteen VMT eyes treated with intravitreal ocriplasmin injection. Sixteen healthy eyes were considered as controls. Macular perfusion density in 3 plexuses [superficial capillary plexus (SCP), deep capillary plexus (DCP), choriocapillaris (CC)] was calculated at baseline and at 1 month after injection.Results: After injection, VMT anatomically resolved in 9 eyes (56.2%), whereas 7 eyes (43.8%) achieved an incomplete VMT separation. Superficial capillary plexus perfusion density was reduced significantly after injection (from 0.427 ± 0.027 to 0.413 ± 0.028; p = 0.0146), while no differences were noted in the DCP (p = 0.2717) nor in the CC (p = 0.6848). Study-eye perfusion density was statistically similar to control eyes in all three plexuses, both at baseline and at follow-up. The FAZ in the SCP area remained unchanged after injection (p = 0.168) but was significantly inferior to controls both at baseline and at 1 month (0.198 ± 0.074 vs. 0.196 ± 0.070; p = 0.007).Conclusions: Eyes with VMT have a perfusion density comparable to healthy controls, but a smaller FAZ. After ocriplasmin injection the perfusion density in the SCP is reduced, regardless the anatomical success. Limited by the small sample size and the pilot nature of the study, we found microvascular changes after ocriplasmin injection, which may be due to retinal traction release. [ABSTRACT FROM AUTHOR]

Background: The objective of this study is to measure the diameter size of foveal avascular zone (FAZ) in both eyes of healthy young adults using optical coherence tomography (OCT) angiography., Methods: A cross sectional study to measure the foveal avascular zone in healthy young adults. Subjects underwent OCT angiography using Zeiss AngioPlex OCT angiography in both eyes., Results: 30 eyes of 15 healthy young adults were evaluated. The mean horizontal FAZ diameter of superficial vascular plexus was 661.166 ± 119.99 microns and mean vertical FAZ diameter was 660.033 ± 96.169 microns (P = 0.9442). The mean horizontal FAZ diameter of deep vascular plexus was 1011.2 ± 154.526 microns and the mean vertical FAZ diameter of deep vascular plexus was 818.033 ± 102.108 microns. There was no difference between the contralateral eyes of subjects in FAZ diameter of both superficial and deep capillary plexuses., Conclusion: The mean diametric size of FAZ in superficial capillary plexus is 660.599 ± 0.801 microns and deep capillary plexus is 914.616 ± 136.589 microns. There was no significant difference with the contralateral eyes.