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Sulphate ions removal from Acid mine drainage (AMD) is crucial to mitigate its adverse impact on aquatic and terrestrial ecosystem. Similarly, surplus and unused quantity of the Fly ash, waste from coal-based power plants is also challenging problem. In the present study, Fly ash based low-cost adsorbents (NaOH at 100 oC and HCL at 400 oC) activated Fly ash were synthesized using thermal activation methods. The composition and surface morphology studies were conducted using FTIR, XRD, XRF and SEM-EDX analysis. The Synthesized adsorbents were used to removal of sulphatic ion under various experimental conditions such as initial concentration (5 to 50 mg L−1), contact time (0 to 180 minutes), dose (5 to 40 mg L−1), solution pH (4.5, 5 and 5.5 pH). The optimum removal was 63 ± 1.4 % and 65 ± 1.6 % at room temperature 27 °C, pH 5.5 and 0.6 g L−1 dose of FAZ-HCl and FAZ-NaOH adsorbents respectively. The kinetics models and adsorption isotherm were determined to be pseudo second order (R2 > 0.9919) for FAZ-HCl and pseudo first order which (R2 > 0.9857) was validated and fitted by Freundlich isotherm (R2 > 0.9806 and 0.9932) for FAZ-HCl and FAZ-NaOH. [ABSTRACT FROM AUTHOR]

Naveen Kumar Challa, Waleed M Alghamdi, Muhammed S Alluwimi, Saleh Alshammeri Department of Optometry, College of Applied Medical Sciences, Qassim University, Buraidah, AlQassim, Saudi ArabiaCorrespondence: Naveen Kumar Challa, Department of Optometry, College of Applied Medical Sciences, Qassim University, Buraidah, AlQassim, Saudi Arabia, Tel +966531177518, Email N.challa@qu.edu.saAim: To assess and compare subclinical alterations in superficial capillary plexus vessel density (SCPVD) and retinal layers thickness in the macular region between individuals with type 2 diabetes mellitus (DM) and healthy controls.Methods: Swept-source OCT images were obtained from 29 control subjects and 24 diabetic subjects. Macular thickness (MT), retinal nerve fiber layer (RNFL) thickness, and ganglion cell layer (GCL) thickness were measured in the central macula and four quadrants of macular region using a 6.0 × 6.0 mm radial macular scan centered on the fovea. OCTA acquisition included a 3.0 × 3.0 mm macular scan for the foveal avascular zone (FAZ) and a 4.5 × 4.5 mm macular scan for SCPVD. The FAZ was manually mapped at the SCP on OCTA images.Results: In diabetic subjects, the superficial capillary plexus vessel density (SCPVD) was significantly lower in both the central (P = 0.04) and inferior (P = 0.01) regions compared to the control group. Additionally, diabetic patients showed a significant reduction in temporal macular thickness (MT) and thinning of the ganglion cell layer (GCL) in all three quadrants except in the central and inferior macula (P < 0.05). There was also significant thinning of the superior macular retinal nerve fiber layer (RNFL) in diabetics compared to controls (P = 0.02). While the foveal avascular zone (FAZ) was larger in diabetic subjects, this difference was not statistically significant (P = 0.78). Duration of diabetes has shown a significantly high positive correlation (r = 0.77, P < 0.01) with superior macular VD.Conclusion: The findings of this study suggest that the diabetic macula experiences significant ganglion cell layer (GCL) thinning and reduced superficial capillary plexus (SCP) vascular density even before the onset of clinical retinopathy. Swept-source OCT proves to be an essential tool for detecting these early changes in diabetic patients.Keywords: tomography, age, RNFL, SCPVD, FAZ, diabetes mellitus

Objective Methods Results Conclusion This study aimed to analyze the microcirculation of the macula, the optic nerve, and the choroid in patients with migraine by optical coherence tomography angiography (OCTA) during spontaneous migraine attacks, comparing the findings with scans performed in the interictal period in the same subjects and healthy controls (HCs).In this case‐crossover design study, patients diagnosed with migraine who underwent an OCTA during a migraine attack were enrolled. A cohort of HCs was recruited for comparison. Data from ocular and orthotic examinations and clinical and demographical information were collected. All subjects were imaged with Solix full range OCT, recording the following parameters: macular vessel density (VD), inside disc VD, peripapillary VD, disc whole image VD, fovea choriocapillaris VD, fovea VD, parafovea VD, peripapillary thickness, fovea thickness, parafovea thickness, macular full retinal thickness, and foveal avascular zone (FAZ).Thirteen patients (26 eyes individually assessed) with a diagnosis of migraine were included (9 without aura [69.2%] and 4 with aura [30.7%], with a mean age of 25.2 ± 3.4 years) and scanned during the ictal and interictal phase. Fifteen age‐matched HCs (30 eyes individually assessed) were included. The foveal choriocapillaris VD was significantly lower in the ictal phase (63.3 ± 2.47%) compared to the interictal phase in the same patients (64.9 ± 2.79%) (p = 0.0019). Comparing the ictal scans from migraine patients and HCs, the FAZ area was significantly larger, and the inside disc, fovea, and fovea choriocapillaris VDs were significantly lower.The study demonstrated a dynamic decrement in choroidal vascularization in migraine patients during spontaneous migraine attacks. [ABSTRACT FROM AUTHOR]

The primary aim of this study was to assess the size and shape of the Foveal Avascular Zone (FAZ) in patients with type 2 diabetes mellitus compared to healthy subjects. The study used 80 OCTA images from the FAZID dataset. The FAZ size was measured by its area, perimeter, and maximum/minimum Feret diameters. The shape was assessed using the axial ratio, circularity, roundness, and solidity. These metrics were calculated automatically using Matlab® R2020b. Statistical analysis was performed using SPSS statistical software version 28.0, with a p-value of less than 0.01 considered significant. The results showed that the FAZ area was significantly larger in diabetic eyes (mean = 0.50 mm2) compared to control eyes (mean = 0.37 mm2), with a p-value of less than 0.01. Both the maximum and minimum diameters of the FAZ were also significantly larger in diabetic groups compared to the control group. Parameters associated with FAZ’s shape were significantly smaller in the diabetic groups than in the control group, except for the axial ratio. The main finding of this study is that diabetic eyes without clinically detectable diabetic retinopathy exhibit morphological changes and irregularities at the FAZ border.

Background/Objectives: This study aims to investigate the long-term effect of inactive systemic lupus erythematosus (SLE) on the retinal microcirculation measured via optical coherence tomography angiography (OCT-A). Methods: Twenty-four eyes of 24 patients with inactive SLE under hydroxychloroquine (HCQ) therapy were included. The OCT-A data (mainly vessel density (VD) and foveal avascular zone (FAZ) data of the superficial and of the deep capillary plexus (SCP, DCP) and the choriocapillaris (CC)) were analyzed and compared between the baseline examination (t0) and 2 years later (t1). Results: At t1, VD in the whole en face SCP and in the CC was notably reduced compared to t0 (SCP: p = 0.001, CC: p = 0.013). VD in the DCP, CRT and FAZ area showed no difference at t1 compared to t0 (DCP: p = 0.128, FAZ: p = 0.332, CRT fovea: p = 0.296). Correlation analysis between the increase in cumulative doses of HCQ between t0 and t1 and the VD of the whole en face SCP did not show any correlation (Spearman r = 0.062 (95% CI −0.367; 0.477). Conclusions: SLE patients demonstrated a decrease in the retinal VD of the SCP and CC over a 2-year period. There was no correlation with the change in cumulative doses of HCQ. These results suggest an ongoing effect of the disease on the retinal and choriocapillary microcirculation. [ABSTRACT FROM AUTHOR]

OBJECTIVE: This study aimed to determine the prognostic value of Optical Coherence Tomography Angiography (OCTA) in drytype age-related macular degeneration (AMD). PATIENTS AND METHODS: Thirty-five eyes of 25 patients with dry-type AMD were included in the study. All patients underwent a complete ophthalmological examination. First and last foveal avascular zone (FAZ), foveal density (FD), FAZ perimeter, non-flow area (NFA), foveal (F)-parafoveal-perifoveal superficial and deep capillary plexus (SCP-DCP) vessel density (VD) OCTA measurements were recorded. Foveal thickness (FT), macular volume (MV), and choroidal thickness (CT) measurements with enhanced depth imaging (EDI) mode were made with Optical Coherence Tomography (OCT). The relationship of all parameters with the best corrected visual acuity (BCVA-logmar) was evaluated. A p-value <0.05 was considered statistically significant. RESULTS: The mean age of the patients was 73.3±11.8 (45-91) years. There was a statistically significant difference between the first and last BCVA, FT, and FD. While FD and BCVA increased, FT was found to decrease statistically significant (p=0.002, p=0.001, p=0.045, respectively). The correlation of BCVA with other variables at the first and last visit was examined. There was a statistically positive correlation between BCVA and FAZ, FAZ perimeter, and NFA in the first and last measurements. In the second measurement, a statistically negative correlation was found between BCVA and MV, FT, superficial FVD, superficial FT, deep FT, superficial parafoveal VD, superficial parafoveal FT, deep parafoveal FT, deep parafoveal VD, and FD variables. CONCLUSIONS: There are positive and negative correlations between OCTA parameters and BCVA in the SCP-DCP in dry-type AMD. OCTA has prognostic significance in dry AMD. [ABSTRACT FROM AUTHOR]

Ocular manifestations have been described in the course of various types of vasculitis. However, there seems to be no routine ophthalmological examinations for patients suffering from those diseases. To ensure holistic care we aimed to investigate any retinal and choroidal abnormalities in patients suffering from primary vasculitis. The objective was to use non-invasive methods, which would not be time- and cost-consuming, yet would be helpful in routine tests. We conducted a prospective and observational study in 41 patients (78 eyes) with 5 types of primary vasculitis, including: Takayasu's arteritis; giant cell arteritis; Buerger's disease; granulomatosis with polyangiitis; and polyarteritis nodosa. A total of 44 healthy individuals were enrolled in the control group for comparison (88 eyes). With the use of optical coherence tomography, optical coherence tomography angiography, and MATLAB, the following parameters were assessed: choroidal thickness; vascularity index; area and perimeter of foveal avascular zone; and circularity index. The following parameters were lower in the study group compared to the control group: mean nasal and temporal CTs; mean central, temporal, and nasal CVI; and mean CI. In contrast, the results of mean central CT as well as the area and perimeter of FAZ were higher in the study group. The differences were statistically significant in the case of all parameters except for CI. Conducting routine ophthalmological examinations in patients diagnosed with vasculitis by assessment of the retina and choroid by measuring parameters like CT, CVI, area and perimeter of FAZ, and CI could be beneficial, as it may detect pathological changes before any ocular symptoms alarm the patients. CVI seems to be especially promising for choroidal evaluation, as it appears to be less influenced by various factors compared to CT. [ABSTRACT FROM AUTHOR]

Optical coherence tomography angiography (OCTA) is a new non-invasive imaging technology that provides detailed visual information on retinal biomarkers, such as the retinal vessel (RV) and the foveal avascular zone (FAZ). Ophthalmologists use these biomarkers to detect various retinal diseases, including diabetic retinopathy (DR) and hypertensive retinopathy (HR). However, only limited study is available on the parallel segmentation of RV and FAZ, due to multi-scale vessel complexity, inhomogeneous image quality, and non-perfusion, leading to erroneous segmentation. In this paper, we proposed a new adaptive segmented deep clustering (ASDC) approach that reduces features and boosts clustering performance by combining a deep encoder–decoder network with K-means clustering. This approach involves segmenting the image into RV and FAZ parts using separate encoder–decoder models and then employing K-means clustering on each part separated by the encoder–decoder models to obtain the final refined segmentation. To deal with the inefficiency of the encoder–decoder network during the down-sampling phase, we used separate encoding and decoding for each task instead of combining them into a single task. In summary, our method can segment RV and FAZ in parallel by reducing computational complexity, obtaining more accurate interpretable results, and providing an adaptive approach for a wide range of OCTA biomarkers. Our approach achieved 96% accuracy and can adapt to other biomarkers, unlike current segmentation methods that rely on complex networks for a single biomarker. [ABSTRACT FROM AUTHOR]

Purpose : To evaluate macular microvascular changes in the form of foveal avascular zone (FAZ) area and vessel density in the superficial, deep capillary plexuses, and choriocapillaris using optical coherence tomography angiography (OCTA) in children with anisometropic myopic amblyopia before and after treatment. Methods: This prospective observational study included 32 patients younger than 12 years old with anisomyopic amblyopia. OCTA was done before patients' treatment with optical correction with or without patching and was repeated after successful amblyopia treatment. Outcomes included superficial, deep, and choriocapillaris vessel density (VD) and superficial and deep FAZ areas. Results: The study included 13 males (40.6%) and 19 females (59.4%), and the mean age was 9.52 ± 1.33 years. Fifty-three percent (53%) of patients needed only optical correction, and the remaining 47% needed additional patching therapy. After successful treatment, there was a significant improvement in amblyopic eyes in best-corrected visual acuity (p < 0.001), with higher VD values in superficial capillary plexuses (p < 0.001), deep capillary plexuses (p < 0.001), and foveal choriocapillaris (p = 0.030). In the glasses with patching subgroup, the difference between pre-treatment and post-treatment parameters revealed a significant improvement in vessel density in superficial retinal plexuses (foveal and parafoveal; p values 0.023 and < 0.001, respectively) and deep retinal plexuses (whole image, foveal, and parafoveal; p values 0.003, < 0.001, and 0.002, respectively). While amblyopic eyes treated with glasses alone had a significantly greater difference in choriocapillaris foveal VD (p value = 0.022). Conclusion: After effective amblyopia treatment, amblyopic eyes exhibited improved best-corrected visual acuity and better macular perfusion along the superficial, deep vascular density, and choriocapillaris foveal VD. Clinical trial registration: CinicalTrials.gov Identifier: NCT05223153. [ABSTRACT FROM AUTHOR]

Artur Ma&lstrok;yszczak,1 Magdalena &Zdot;yto,2 Joanna Prze&zacute;dziecka-Do&lstrok;yk,2 Marta Misiuk-Hoj&lstrok;o1 1Department and Clinic of Ophthalmology, Wroclaw Medical University, Wroclaw, Dolnoslaskie, Poland; 2Department of Optics and Photonics, Wroclaw University of Science and Technology, Wroclaw, Dolnoslaskie, PolandCorrespondence: Artur Ma&lstrok;yszczak, Department and Clinic of Ophthalmology, Wroclaw Medical University, Borowska 213 50-556, Wroclaw, Dolnoslaskie, Poland, Email arturm100@gmail.comPurpose: The purpose of this study is to determine the relationships between foveal avascular zone (FAZ), foveal vascular density (FD) and GCC (ganglion cell complex) parameters in a healthy myopic population using optical coherence tomography angiography (angio-OCT).Patients and Methods: Three hundred and eighty-one eyes of 381 healthy participants were included into this study and assigned to three groups according to their spherical equivalent (SE) values and an additional progressive myopia group. One randomly chosen eye from each patient was analyzed. GCC mean thickness, focal loss of volume (FLV), global loss of volume (GLV), FAZ area, FAZ perimeter, and FD parameters were obtained with the RTVue AngioOCT device.Results: FAZ area and its perimeter were strongly correlated with the belonging spherical equivalent group (p = 0.0001, p = 0.0008 accordingly), being the largest in progressive myopia subgroup (mean size 0.42mm2). Other factors that were significantly higher in myopic eyes were FLV (p = 0.0023), GLV (p = 0.0020). There were no differences in FD between groups. In the myopic and progressive myopia groups, there was a significant relationship between FAZ area and FLV, GLV, and GCC thickness. We found that in myopic eyes with AXL exceeding 26.6 mm, FAZ becomes negatively correlated to mean GCC thickness.Conclusion: In myopia, compared to non-myopic groups, there is a greater loss of neural tissue represented by a thinner GCC layer, greater FLV and GLV parameters, and worse blood supply represented by a larger FAZ area. Eye axial length of 26.6 mm is a breaking point, where the negative FAZ area to GCC thickness relationship curve is getting significantly steeper.Keywords: GCC, FAZ, optical coherence tomography angiography, OCTA

AbstractOptical coherence tomography angiography (OCT-A) is a noninvasive diagnostic method for three-dimensional visualization of the vascular structures of the retina and choroid. The aim of this study was to evaluate the diagnostic role of OCT-A preoperatively and postoperatively in vitreoretinal interface (VRI) pathologies, by determining the size of the foveal avascular zone (FAZ) in the superficial (SCP) and deep capillary plexus (DCP) and to compare these parameters with control (healthy) eyes. Medical records of 19 patients were prospectively analyzed: nine with a full-thickness macular hole (FTMH) and ten with an idiopathic epiretinal membrane (ERM). All participants underwent unilateral Pars Plana Vitrectomy, peeling of internal limiting membrane and fluid-gas exchange tamponade. The FAZ area of the SCP and DCP was statistically significantly different preoperatively and postoperatively at the 1st month in the FTMH group (0.5311 ± 0.276 mm2 vs. 0.4278 ± 0.257 mm2, p-value .000; 1.4822 ± 0.727 mm2 vs. 0.5856 ± 0.498 mm2 p-value .005). The mean preoperative FAZ in both plexuses was bigger compared to the control eyes. The FAZ area of the SCP and DCP was nonsignificantly different preoperatively and postoperatively in patients with ERM, despite a decrease in the mean FAZ area at the 1st month (0.3120 ± 0.1134 mm2 vs. 0.2300 ± 0.1158 mm2, p-value .150; 0.7100 ± 0.6607 vs. 0.5190 ± 0.5591 mm2, p-value .091). The results of this prospective study suggest that OCT-A is an effective and safe method in VRI pathologies, giving a valuable information for surgical outcome. Due to its high diagnostic value, the prognosis for the recovery of visual function after surgical treatment can be assessed.

Objective: The aim of this study was to evaluate the microvasculature of the macula and the optic nerve in patients affected by migraine with aura (MA) and without aura (MO) by optical coherence tomography angiography (OCTA), comparing the findings with healthy controls (HC). Methods: We collected data from ocular and orthotic examinations, including eye motility, intraocular pressure measurement, best-corrected visual acuity (BCVA) measurement, objective refraction measurement, fundus examination, macular and optic disk OCTA examination. All subjects were imaged with solix fullrange OCT. The following OCTA parameters were recorded: macular vessel density (VD), inside disc VD, peripapillary VD, disc whole image VD, fovea choriocapillaris VD, fovea VD, parafovea VD, peripapillary thickness, fovea thickness, parafovea thickness, macular full retinal thickness, and foveal avascular zone (FAZ) parameters. Clinical and demographical data about migraine patients were collected by a neurologist. Results: We included 56 eyes from 28 patients with a diagnosis of MO, 32 eyes from 16 patients with a diagnosis of MA, and 32 eyes from 16 HC subjects. The FAZ area was 0.230 ± 0.099 mm2 in the MO group, 0.248 ± 0.091 mm2 in the MA group and 0.184 ± 0.061 mm2 in the control group. The FAZ area was significantly larger in the MA group than in the HC group (p = 0.007). The foveal choriocapillaris VD was significantly lower in MA patients (63.6 ± 2.49%) when compared with MO patients (65.27 ± 3.29%) (p = 0.02). Conclusion: An impairment of retinal microcirculation can be detected in patients with MA, as demonstrated by the enlargement of FAZ. Moreover, the study of choroid circulation may reveal microvascular damage in patients with migraine with aura. OCTA is a useful non-invasive screening tool for the detection of microcirculatory disturbance in patients with migraine. [ABSTRACT FROM AUTHOR]

This study aimed to evaluate foveal avascular zone (FAZ) features and macular flow density (FD) in various retinal layers in a cohort of patients with foveal hypoplasia (FH) using optical coherence tomography angiography (OCTA), in order to characterize microvascular abnormalities and explore their potential clinical significance. FAZ parameters and FD, as well as retinal thickness and volume values were analyzed and compared between patients with FH and an age- and gender-matched control cohort. Correlations between disease severity and visual acuity (VA), as well as between disease severity and FAZ features were evaluated. A total of 19 eyes with FH and 19 control eyes were included. The study group showed significantly higher FD values in the foveal sectors of the superficial and deep capillary plexus compared to controls. FAZ area, perimeter, and acircularity index (ACI) were noticeably altered in eyes with FH; however, they did not correlate with disease severity. Visual acuity was negatively correlated with disease severity. The results of this study provide evidence of altered microvasculature architecture specifically in the foveal sectors of patients with FH. The higher FD values in the foveal sectors of FH patients suggest a potential compensatory response of the retinal microvasculature. FAZ parameters and FD values of the foveal sectors could be used as part of an OCTA-based grading system in FH patients. [ABSTRACT FROM AUTHOR]

Diabetic macular edema (DME) is one of the main ocular complications of diabetes mellitus (DM) that can lead to important vision loss in diabetic patients. In clinical practice, there are cases of DME with unsatisfying treatment responses, despite adequate therapeutic management. Diabetic macular ischemia (DMI) is one of the causes suggested to be associated with the persistence of fluid accumulation. Optical coherence tomography angiography (OCTA) is a non-invasive imaging modality, able to give in-depth information about retinal vascularization in a 3-dimensional manner. The OCTA devices currently available can provide various OCTA metrics that quantitatively assess the retinal microvasculature. In this paper, we reviewed the results of multiple studies that investigated the changes in OCTA metrics in the setting of DME and their possible contribution to the diagnosis, therapeutic management, follow-up and prognosis of patients with DME. We analyzed and compared relevant studies that investigated OCTA parameters related to changes in macular perfusion in the setting of DME and we evaluated the correlations between DME and several quantitative parameters, such as vessel density (VD), perfusion density (PD), foveal avascular zone (FAZ)-related parameters, as well as complexity indices of retinal vasculature. The results of our research showed that OCTA metrics, evaluated especially at the level of the deep vascular plexus (DVP), are useful instruments that can contribute to the assessment of patients with DME. [ABSTRACT FROM AUTHOR]

Background: Hypertension (HTN) affects cardiovascular, renal and neurological systems. The poorly controlled blood pressure may also cause structural and functional retinal damage. Objective: To assess changes in foveal avascular zone (FAZ) and macular vessel density using Optical Coherence Tomography Angiography (OCTA) in hypertensive patients. Patients and Methods: This case control observational study was performed on 120 eyes, divided into 3 groups. Group A: 40 eyes of 26 patients with HTN for more than 10 years, group B: 40 eyes of 22 patients with HTN less than 10 years, and group C: 40 eyes of 20 normal subjects with completely normal ophthalmological examination. All participants underwent OCTA. Results: There was no significant variation in age, gender or FAZ between the three studied groups. Superficial capillary plexuses in parafovea, parafovea superior hemi, parafovea inferior hemi, perifovea, perifovea superior hemi, and perifovea inferior hemi were considerably higher in group C than in group A (p =0.002, 0.001, 0.011, 0.014, 0.041, and 0.002, respectively) and group B (p <0.001). Deep capillary plexuses in parafovea, parafovea superior hemi, parafovea inferior hemi, perifovea, perifovea superior hemi, and perifovea inferior hemi were considerably higher in group C than in group A (p <0.001), and group B (p =0.004, 0.004, 0.003, 0.002, 0.001, and 0.003, respectively). No significant difference were observed in the studied parameters between group A and B. Conclusion: Eyes of HTN patients have lower macular vessel densities (superficial and deep) compared to those of healthy controls. The duration and control of hypertension didn't account any substantial differences between the two groups of hypertensive patients. [ABSTRACT FROM AUTHOR]

Purpose: To study the foveal avascular zone (FAZ) and the vessel densities (VD) in diabetic patients using optical coherence tomography angiography (OCT-A) and inner retinal layer changes to compare patients affected by type 1 diabetes (DM1) and type 2 diabetes (DM2). Methods: Cross-sectional observational study involving 150 eyes of 150 patients with DM1, and 155 eyes of 155 patients with DM2 with diabetic retinopathy (DR). Retinal nerve fiber layer (RNFL) and Ganglion cell layer (GCL) were evaluated. OCT-A studied both FAZ and VD at the level of the superficial capillary plexus (SCP) and the deep capillary plexus (DCP). Results: A statistically significant difference in FAZ area and foveal VD measured at the SCP (p < 0.001) was noted between DM1 and DM2 groups when comparing patients with mild and moderate non-proliferative diabetic retinopathy (NPDR), while no differences were found in the severe NPDR and proliferative diabetic retinopathy (PDR) subgroups. Duration of diabetes and stage of DR were directly correlated with enlargement of FAZ area and inversely correlated with foveal VD measured at SCP. RNFL and GCL were not different between DM1 and DM2 groups. Conclusion: Changes in OCT-A parameters detected in FAZ area and VD of diabetic patients with different stages of DR may help to predict the risk for progression of the disease. [ABSTRACT FROM AUTHOR]

Background and objectives: This study aimed to analyze the morphological changes in the foveal avascular zone (FAZ) after panretinal photocoagulation (PRP) in patients with diabetic retinopathy, with a particular focus on the presence or absence of comorbid diabetic macular ischemia (DMI), using optical coherence tomography angiography (OCTA). Materials and Methods: Treatment-naïve 25 eyes of 16 patients who received PRP were examined in this retrospective case series. FAZ area, perimeter, and circularity were calculated on a 3 × 3-mm en-face OCTA image before PRP (baseline) and 1 and 3 months after PRP. The patients were divided into two groups according to coexisting DMI, and each group was statistically analyzed. Results: In patients with DMI (9 eyes), FAZ area significantly decreased from the baseline to 3 months after PRP (0.86 ± 0.56 to 0.61 ± 0.31 mm2, p = 0.018), whereas FAZ perimeter and circularity remained unchanged following treatment (p = 0.569 and 0.971, respectively). In patients without DMI (16 eyes), FAZ parameters did not show statistically significant changes across the 3-month follow-up period. Conclusion: PRP significantly reduces FAZ area in patients with DMI. [ABSTRACT FROM AUTHOR]

Optical coherence tomography angiography (OCTA) is a new non-invasive imaging technology that provides detailed visual information on retinal biomarkers, such as the retinal vessel (RV) and the foveal avascular zone (FAZ). Ophthalmologists use these biomarkers to detect various retinal diseases, including diabetic retinopathy (DR) and hypertensive retinopathy (HR). However, only limited study is available on the parallel segmentation of RV and FAZ, due to multi-scale vessel complexity, inhomogeneous image quality, and non-perfusion, leading to erroneous segmentation. In this paper, we proposed a new adaptive segmented deep clustering (ASDC) approach that reduces features and boosts clustering performance by combining a deep encoder–decoder network with K-means clustering. This approach involves segmenting the image into RV and FAZ parts using separate encoder–decoder models and then employing K-means clustering on each part separated by the encoder–decoder models to obtain the final refined segmentation. To deal with the inefficiency of the encoder–decoder network during the down-sampling phase, we used separate encoding and decoding for each task instead of combining them into a single task. In summary, our method can segment RV and FAZ in parallel by reducing computational complexity, obtaining more accurate interpretable results, and providing an adaptive approach for a wide range of OCTA biomarkers. Our approach achieved 96% accuracy and can adapt to other biomarkers, unlike current segmentation methods that rely on complex networks for a single biomarker.

The identification of non-invasive biomarkers to investigate and monitor retinal structural and vascular changes in multiple sclerosis (MS) represents an interesting source of debate. Until now optical coherence tomography angiography (OCTA) evaluated the foveal avascular zone (FAZ) and areas of retinal non-perfusion only in the macular region in MS patients. It could be interesting to identify possible biomarkers, useful in assessing the ischemic areas also in the near peripheral retina, since FAZ enlargement and the areas of peripheral retinal non-perfusions share common pathogenic processes. In this cross-sectional study, we investigated the correlation between the FAZ area and retinal vessel density (VD) in the near peripheral retina by new wide-field optical coherence tomography angiography (OCTA) in patients affected by relapsing-remitting multiple sclerosis (RR-MS). Moreover, we compared the FAZ area and the VD of superficial and deep capillary plexuses in the fovea region and in the near peripheral retina (6.4 × 6.4 mm) between RR-MS patients and healthy controls by means of a Solix full-range OCTA. Last, we also detected the changes in structural OCT parameters (ganglion cell complex and retinal nerve fiber layer). Thirty-three eyes of 33 RR-MS patients and 35 eyes of 35 healthy controls were enrolled. RR-MS patients showed a lower VD in the superficial capillary plexus and a significant increase in the FAZ area compared with controls. The deep capillary plexus revealed a reduced VD although not statistically significant in patients with respect to controls. In the patients' group, the FAZ area showed significantly negative correlations with VD of superficial capillary plexuses in the foveal and whole region, while the FAZ area did not negatively correlate with the VD of the deep capillary plexus. The significant correlations among OCTA parameters could demonstrate the FAZ area as a possible biomarker for assessing the perfusion status in the near peripheral retina, useful in RR-MS management. These findings could confirm the role of vascular dysfunction in the pathogenetic mechanisms of MS.

Diabetic macular edema (DME) is one of the main ocular complications of diabetes mellitus (DM) that can lead to important vision loss in diabetic patients. In clinical practice, there are cases of DME with unsatisfying treatment responses, despite adequate therapeutic management. Diabetic macular ischemia (DMI) is one of the causes suggested to be associated with the persistence of fluid accumulation. Optical coherence tomography angiography (OCTA) is a non-invasive imaging modality, able to give in-depth information about retinal vascularization in a 3-dimensional manner. The OCTA devices currently available can provide various OCTA metrics that quantitatively assess the retinal microvasculature. In this paper, we reviewed the results of multiple studies that investigated the changes in OCTA metrics in the setting of DME and their possible contribution to the diagnosis, therapeutic management, follow-up and prognosis of patients with DME. We analyzed and compared relevant studies that investigated OCTA parameters related to changes in macular perfusion in the setting of DME and we evaluated the correlations between DME and several quantitative parameters, such as vessel density (VD), perfusion density (PD), foveal avascular zone (FAZ)-related parameters, as well as complexity indices of retinal vasculature. The results of our research showed that OCTA metrics, evaluated especially at the level of the deep vascular plexus (DVP), are useful instruments that can contribute to the assessment of patients with DME.

Background: Smoking cause alterations in the retinal blood flow and damage of the blood retinal barrier, these retinal microvascular changes demonstrated by OCT-A may be an indicator of systemic microvascular changes. Objective: The purpose of this study was to evaluate the effect of active and passive smoking on macula and optic nerve by measuring the macular thickness and microvasculature, GCC thickness, RNFL thickness and disc microvasculature using OCTA. Methods: 150 healthy participants of 76 males and 74 females, divided in to three equal groups active smoker, passive smoker and control group. Optical coherence tomography angiography scanning was performed for all subjects. All macular subfields thickness, peripapillary retinal nerve fiber layer (RNFL) thickness, ganglion cell complex (GCC) thickness, superficial and deep macular vessel density, foveal avascular zone (FAZ) area and radial peripapillary capillaries (RPC) density were measured and analyzed. Results: Significant increase in the central macular thickness in the active and passive smoker, also there was significant decrease in the superior RNFL and deep parafoveal vessel density in the active and passive smoker, but no significant differences in GCC, FAZ, superficial capillary plexus(SCP) density, and radial peripapillary capillaries density between the three groups. Conclusion: Active and passive smoking decrease deep parafoveal vessel density, superior retinal nerve fiber layer thickness, and increase central, inner and outer macular thickness in healthy middle age individuals. [ABSTRACT FROM AUTHOR]

Background: Leukemia is a neoplastic blood disorder characterized by an abnormal proliferation of leukocytes. Knowledge of ocular involvement in leukemia is important because the eye is the only site where the leukemic involvement of nerves and blood vessels can be directly observed, because the eye symptoms may be the initial mode of presentation of the systemic illness. Almost all ocular structures have been found to be involved in patients with various types of leukemia. Objective: To detect retinal and peripapillary vascular changes in newly diagnosed acute leukemic patients prior to chemotherapy treatment using optical coherence tomography angiography. Patients and Methods: This comparative cross sectional study was carried out on 52 eyes of 26 patients and 52 eyes of 26 healthy subjects. Optical coherence tomography angiography was performed for all subjects. Central macular thickness. Retinal nerve fiber layer thickness, ganglion cell complex thickness, superficial and deep vessel density, foveal avascular zone area and radial peripapillary capillaries density weremeasured and analyzed. Results: Significant decrease in the superficial capillary plexus and the radial peripapillary capillary density in the cases group. The FAZ area is larger in the cases group. The central macular thickness is lower in the cases group. But the RNFL thickness, and C/D parameters were higher in the case group. However, there was no significant difference between the two groups regarding the GCC and the DCP density. Conclusion: Acute leukemia causes decrease in superficial capillary plexus density and radial peripapillary capillaries density and decreased macular thickness with no affection in deep capillary vessel density. [ABSTRACT FROM AUTHOR]

The purpose of this study was to evaluate retinal and choroidal microvascular alterations with optical coherence tomography angiography (OCTA) in COVID-19 patients hospitalized because of bilateral pneumonia caused by SARS-CoV-2. The vessel density (VD) and foveal avascular zone (FAZ) of 63 patients with SARS-CoV-2 pneumonia who had positive polymerase chain reaction (PCR) tests and who recovered after receiving treatment and 45 healthy age- and gender-matched controls were evaluated and compared using OCTA in the superficial capillary plexus (SCP) and deep capillary plexus (DCP). The VD was also estimated in both groups in the choriocapillaris (CC). In COVID-19 patients, there was a statistically significant difference between the patients and a control group in both superficial (FAZs) and deep (FAZd) avascular zone (p = 0.000). The VD was significantly lower in the foveal area in choriocapillaris (p = 0.046). There were no statistically significant changes in the VD in the superior, inferior, nasal, and temporal quadrants in superficial and deep plexus, or in the choriocapillaris. The VD was not significantly lower in the foveal area in superficial or deep plexus. COVID-19 may affect the retinal vasculature, causing ischemia, enlargement of the FAZ, and lowering of the VD in the choriocapillaris area. Routine ophthalmic examination after SARS-CoV-2 infection should be considered in the course of post-infectious rehabilitation. [ABSTRACT FROM AUTHOR]

This study investigated vascular density and foveal avascular zone (FAZ) parameters using optical coherence tomography angiography (OCT-A) in patients with keratoconus (KC). Participants with KC and healthy controls were included and underwent best-corrected visual acuity (BCVA), keratometry, anterior segment OCT, and macular OCT-A examinations. Of the 70 subjects (mean age 42.9 ± 15.31 years), 79 KC and 47 healthy eyes were included. Significant reductions in the KC group were recorded for the FAZ area, with a mean (±SD) of 0.19 ± 0.12 vs. 0.25 ± 0.09 mm2 p < 0.001. Central vascular density in KC patients was lower compared with the controls: 6.78 ± 4.74 vs. 8.44 ± 3.33 mm−1 p = 0.049; the inner density was also decreased in the study group (13.64 ± 5.13 vs. 16.54 ± 2.89 mm−1, p = 0.002), along with the outer density (14.71 ± 4.12 vs. 16.88 ± 2.42 mm−1, p = 0.004) and full density (14.25 ± 4.30 vs. 16.57 ± 2.48) p = 0.003. Furthermore, BCVA was positively correlated with central vascular density (R = 0.42 p = 0.004, total R = 0.40, p = 0.006) and inner density (R = 0.44, p = 0.002) in patients with KC but not in controls. Additionally, we found a correlation between K2 and inner vascular density (R = −0.30, p = 0.043) and central epithelium thickness and outer density (R = 0.03, p = 0.046). KC patients had lower macular vascular density and a smaller FAZ than healthy participants. The BCVA in KC patients was correlated with the vascular density. [ABSTRACT FROM AUTHOR]

AIM: To observe the short-term efficacy of intravitreal injection of aflibercept on macular edema secondary to retinal vein occlusion(RVO). METHODS: Totally 24 patients(24 eyes)with macular edema secondary to RVO confirmed by ophthalmic clinical examination received intravitreal injection of aflibercept from May to October in 2019 in hospital. Before and after the 1wk, 1mo treatment, all the eyes of the sick were examined with best corrected visual acuity(BCVA), optical coherence tomography angiography(3x3mm scanning range model)BCVA, central macular thickness(CMT), vascular density of superficial capillary plexus(SCP), vascular density of deep capillary plexus(DCP), and the area, perimeter and the roundness index in foveal avascular zone(FAZ)were observed. RESULTS: Intravitreal injection of aflibercept for 1wk and 1mo, BCVA improved with the difference were statistically significant(PPP>0.05), and it revealed there was no obvious change for vascular density of SCP,DCP and FD-300(All P>0.05); The area and perimeter of FAZ after treatment increased obviously, and the roundness index of FAZ decreased than before with the difference were statistically significant(PCONCLUSION: For macular edema secondary to RVO, eyesight improved and edema absorbed obviously with the intravitreal injection of aflibercept in short-term clinical observation. At the same time, FAZ become regular and macular ischemia wasn't aggravated after treatment.

Optical coherence tomography angiography (OCT-A) is a noninvasive diagnostic method for three-dimensional visualization of the vascular structures of the retina and choroid. The aim of this study was to evaluate the diagnostic role of OCT-A preoperatively and postoperatively in vitreoretinal interface (VRI) pathologies, by determining the size of the foveal avascular zone (FAZ) in the superficial (SCP) and deep capillary plexus (DCP) and to compare these parameters with control (healthy) eyes. Medical records of 19 patients were prospectively analyzed: nine with a full-thickness macular hole (FTMH) and ten with an idiopathic epiretinal membrane (ERM). All participants underwent unilateral Pars Plana Vitrectomy, peeling of internal limiting membrane and fluid-gas exchange tamponade. The FAZ area of the SCP and DCP was statistically significantly different preoperatively and postoperatively at the 1st month in the FTMH group (0.5311 ± 0.276 mm2 vs. 0.4278 ± 0.257 mm2, p-value.000; 1.4822 ± 0.727 mm2 vs. 0.5856 ± 0.498 mm2p-value.005). The mean preoperative FAZ in both plexuses was bigger compared to the control eyes. The FAZ area of the SCP and DCP was nonsignificantly different preoperatively and postoperatively in patients with ERM, despite a decrease in the mean FAZ area at the 1st month (0.3120 ± 0.1134 mm2 vs. 0.2300 ± 0.1158 mm2, p-value.150; 0.7100 ± 0.6607 vs. 0.5190 ± 0.5591 mm2, p-value.091). The results of this prospective study suggest that OCT-A is an effective and safe method in VRI pathologies, giving a valuable information for surgical outcome. Due to its high diagnostic value, the prognosis for the recovery of visual function after surgical treatment can be assessed. [ABSTRACT FROM AUTHOR]

Purpose: To compare vessel density (VD) as measured by optical coherence tomography angiography (OCTA), in uveitic eyes with secondary glaucoma (UG) with VD in uveitic eyes without glaucoma (UV), eyes with primary open-angle glaucoma (POAG), and healthy eyes (HY). Methods: VD was measured at the following segmentation areas: radial peripapillary capillaries, superficial (SL) and deep vascular plexus (DL) and choroid. Results: The majority of the measured papillary areas showed significantly lower VD in the UG group than in the HY group. In macular area, in the superficial vascular plexus wholeVD was significantly lower than in the healthy group, as well as in four other quadrants. In DL no significant differences could be found. At choroidal level, the VD of UG group were significantly lower in two quadrants than in UV group. Conclusions: OCTA can be used to detect differences in VD in papillary and macular region of uveitis glaucoma eyes. [ABSTRACT FROM AUTHOR]

BACKGROUND: Tea, second only to water, is one of the most regularly consumed drinks in the world. Its potentially beneficial effects on general health may be enormously important. Optical coherence tomography angiography (OCTA) now allows clinicians to examine the acute retinal morphological changes caused by black tea consumption. The purpose of this study was to investigate the acute impacts of a Camellia sinensis fermentation end‐product (black tea) on retinal microvasculature in healthy individuals using OCTA. RESULTS: In this study, 60 healthy people were divided into two groups: group 1 (n = 30) received black tea (2 mg/250 mL of water) and group 2 (n = 30) received only 250 mL of water. Following consumption, AngioVue Analytics software automatically analyzed the foveal, parafoveal, perifoveal macular superficial and deep vascular plexus densities, foveal avascular zone (FAZ) area, FAZ perimeter and foveal vessel density in a 300 μm wide region around the FAZ (FD‐300). Male‐to‐female ratios were 19:11 and 15:15 in groups 1 and 2, respectively (P = 0.217). Mean age was 33.27 ± 7.92 years in group 1 and 31.00 ± 7.30 years in group 2 (P = 0.254). Changes in foveal, perifoveal and parafoveal macular vessel density between groups 1 and 2 were not statistically significant. In addition, no significant differences regarding FAZ, FAZ perimeter and FD‐300 were observed. CONCLUSION: There were no acute effects of black tea on macular microcirculation in healthy individuals. The authors, however, believe that this study could serve as a model for future research on the relationship between regular tea consumption and general ocular physiology. © 2021 Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

Background: To investigate the effect of iron overload on macular perfusion among transfusion-dependent thalassemia (TDT) patients using optical coherence tomography angiography (OCTA) Methods: The study is a prospective observational case–control study. It included 27 eyes from 27 children with transfusion-dependent β-thalassemia and 25 eyes from 25 age-matched controls. All participants were evaluated clinically and with OCTA Avanti RTVue-XR system (Optovue) to assess macular microvascular changes, by measuring vessels density (VDs) and foveal avascular zone (FAZ) area, at both superficial and deep retinal plexuses and at choriocapillaris level. Results: Foveal and parafoveal zones were significantly thinner among thalassemia patients, with significantly larger FAZ area at the level of both superficial and deep retinal plexuses when compared with control group. The thalassemia group showed significant lower values compared with the controls regarding whole-image, foveal, and parafoveal deep VD. There were significant negative correlations between serum ferritin and deep (whole image and parafoveal) VD (r = − 0.429, P = 0.026, and r = − 0.452, P = 0.018, respectively). Choriocapillaris VDs (whole image and foveal) showed significant negative correlations with serum ferritin levels (r = − 0.390, P = 0.044 and r = − 0.401, P = 0.038, respectively) Conclusions: Macular microvascular changes were detected by OCTA examination in patients with TDT, mostly due to iron overload effect, as we selected patients on iron-chelating agent with the least harmful effect on the retina. The most affected layer is the DCP. Changes at the deep layer could be used as a sensitive biomarker for early macular perfusion changes in those patients. Trial registration : Study registration number is UMIN000042657, date of registration: 2020/12/04 (retrospectively registered). [ABSTRACT FROM AUTHOR]

Background: Diabetic retinopathy (DR) is mostly a vascular disease where the development of macular oedema and proliferative retinopathy are major causes of visual impairment. Enlargement of the foveal avascular zone (FAZ) is associated with visual deterioration in patients with diabetic retinopathy. Objective: To evaluate the foveal avascular zone (FAZ) and perifoveal capillary network density in the superficial retinal layer (SRL) and deep retinal layer (DRL) in patients with varying severities of diabetic retinopathy (DR). Patients and methods: This is a prospective comparative randomized case-control study consisting of 77 eyes divided into two groups, each group underwent imaging using OCT-A device. Group one: 37 healthy control eyes, and group two: 40 eyes with DM of different degrees of diabetic retinopathy. Subjects were imaged between September 2019 and February 2020 at Kasr El-Ainy Teaching Hospital. Results: The FAZ area at the levels of the superficial and deep vascular networks of eyes with DR were found to be larger compared with those of age-matched healthy controls, and as would be expected, control eyes had higher vascular density in both networks compared with the diabetic eyes. Furthermore, eyes with worse DR stage showed larger FAZ area and lower vascular density values. This study also showed that angiographic parameters, namely FAZ area and vessel density (VD) correlated with best corrected visual acuity. Conclusion: Our study revealed that vascular density and FAZ area can be quantified in DR eyes in a rapid, automated, and noninvasive manner with OCTA. Also foveal avascular zone area and vascular density as measures of DMI correlate with visual acuity in patients with DR. [ABSTRACT FROM AUTHOR]

Background: Visual recovery following macula involving rhegmatogenous retinal detachment remains poorly understood. The aim of this work is to correlate the functional and the anatomical changes in retinal vasculature in the foveal avascular zone using optical coherence tomography angiography (OCTA) after successful retinal reattachment repair and correlate this data with retinal thickness and post-operative visual recovery. Methods: A prospective, comparative observational study of 28 eyes of 14 patients with 14 eyes undergoing macula off retinal detachment repair with pars plana vitrectomy, endo-laser and silicone oil-based tamponade compared with 14 fellow healthy eyes at 1, 6 and 12 weeks post-operative period. The study was conducted at the Research Institute of Ophthalmology, Giza, Egypt between February 2018 and August 2018. Results: The foveal avascular zone (FAZ) area in the patients group was not significantly different compared to the control group and was found to be negatively correlated with the central retinal thickness in both the study and control group. The superficial capillary plexus (SCP) area at the FAZ was significantly larger than the deep capillary plexus (DCP) area at the FAZ in both the study and control group over the follow-up period. The DCP area at the FAZ was significantly larger at the 3rd follow-up than the 1st follow-up. The SCP FAZ area was significantly larger than the DCP FAZ area in both the study and control group over the follow-up period. BCVA was found to be negatively correlated to the retinal thickness of the temporal 3 mm paracentral quadrant with no correlation with central foveal thickness (CFT) and the FAZ area. Conclusion: Optical coherence tomography (OCT) and OCTA are valuable noninvasive imaging tools to monitor and predict the structural changes at the foveal avascular zone during the recovery phase after successful retinal reattachment involving macula. [ABSTRACT FROM AUTHOR]

Purpose: The aim of this study was to measure and compare the retinal vascular parameters and foveal avascular zone (FAZ) in Chinese and Caucasian populations by using optical coherence tomography angiography (OCT‐A). Methods: Fifty‐one eyes of Han Chinese and 43 eyes of Caucasians were retrospectively included in our study. The measurements were acquired using Zeiss Cirrus 5000, with the same software version 10 in Poland and China. Results: The size of the FAZ was 0.33 ± 0.012 and 0.28 ± 0.014 mm2 (p = 0.0289) and the diameter was 2.43 ± 0.06 and 2.18 ± 0.07 mm (p = 0.0057) for Chinese and Caucasian populations, respectively. However, no differences were observed in circularities between the populations. The full Early Treatment of Diabetic Retinopathy Study (ETDRS) vessel length density was significantly different for Chinese (17.05 ± 0.24 mm/mm2) and Caucasian (16.08 ± 0.43 mm/mm2) populations. In addition, the outer ETDRS vessel length density was significantly different for Chinese (16.43 ± 0.42 mm/mm2) and Caucasian (17.47 ± 0.24 mm/mm2) populations, but the central 7.33 ± 1.68 versus 9.32 ± 1.54 mm/mm2 for the Caucasian and Chinese and inner 16.14 ± 0.52 for Caucasian and 16.93 ± 0.27 mm/mm2 for Chinese subjects density was not. A significant yet weak positive correlation between FAZ and vessel density was observed (r = 0.216). Furthermore, no significant intersexual differences were observed in study parameters. Conclusion: The Chinese population had larger FAZ with higher vessel length density in the superficial layers of the retina than the Caucasian population. [ABSTRACT FROM AUTHOR]

Background: Diabetic retinopathy (DR) is the leading cause of legal blindness in the working population in developed countries. Optical coherence tomography (OCT) angiography (OCTA) has risen as an essential tool in the diagnosis and control of diabetic patients, with and without DR, allowing visualisation of the retinal and choroidal microvasculature, their qualitative and quantitative changes, the progression of vascular disease, quantification of ischaemic areas, and the detection of preclinical changes. The aim of this article is to analyse the current applications of OCTA and provide an updated overview of them in the evaluation of DR. Methods: A systematic literature search was performed in PubMed and Embase, including the keywords “OCTA” OR “OCT angiography” OR “optical coherence tomography angiography” AND “diabetes” OR “diabetes mellitus” OR “diabetic retinopathy” OR “diabetic maculopathy” OR “diabetic macular oedema” OR “diabetic macular ischaemia”. Of the 1456 studies initially identified, 107 studies were screened after duplication, and those articles that did not meet the selection criteria were removed. Finally, after looking for missing data, we included 135 studies in this review. Results: We present the common and distinctive findings in the analysed papers after the literature search including the diagnostic use of OCTA in diabetes mellitus (DM) patients. We describe previous findings in retinal vascularization, including microaneurysms, foveal avascular zone (FAZ) changes in both size and morphology, changes in vascular perfusion, the appearance of retinal microvascular abnormalities or new vessels, and diabetic macular oedema (DME) and the use of deep learning technology applied to this disease. Conclusion: OCTA findings enable the diagnosis and follow-up of DM patients, including those with no detectable lesions with other devices. The evaluation of retinal and choroidal plexuses using OCTA is a fundamental tool for the diagnosis and prognosis of DR.

Purpose: The aim of this study was to evaluate macular perfusion using OCTA automated software algorithms; vessel area density (VD) and non-flow tool to measure FAZ area in treatment-naïve diabetic eyes with moderate or severe NPDR and having macular edema, and correlate these parameters with LogMAR (logarithm of the minimum angle of resolution) visual acuity. Diabetic eyes without macular edema were included, to detect and define differences within the parameters between diabetic eyes with and without macular edema. Methods: Forty-five diabetic eyes with diabetic macular edema, forty diabetic eyes without macular edema, and forty eyes of healthy controls were examined using OCTA (RTVue-XR Avanti; Optovue, Inc, Fremont, CA). The macular vessel area density (VD) and foveal avascular zone (FAZ) area were assessed and statistically compared between the three groups and also correlated with the foveal thickness and visual acuity. Data were entered and analyzed by SPSS 19. Quantitative data were presented as mean and standard deviation, and qualitative data presented as frequency distribution; independent samples t test, Chi square test and Pearson correlation were done. Results: Mean whole image VD was 44.4 ± 3.6 in diabetic eyes with DME, 45.6 ± 4.2 in diabetics without DME, and 49 ± 3.9 in control eyes (P = 0.001). Diabetic eyes with DME had significantly lower vessels density values at the level of the deep retinal plexus (in the parafoveal, superior hemi, inferior hemi, temporal, superior, and nasal areas), when compared with diabetic eyes without DME. In diabetic eyes with DME, significant fair negative correlation was found between whole image vessels density at the level of the superficial retinal plexus and LogMAR VA (r = − 0.313, P = 0.036). Also, a significant fair positive correlation was found between FAZ area (at both the superficial and deep retinal plexus) and LogMAR visual acuity, in diabetic eyes with DME, where eyes with larger FAZ area had worse vision (P = 0.005 and P = 0.016, respectively). Diabetic eyes with DME had significantly larger FAZ area at the level of the superficial capillary plexus (mean superficial FAZ ± SD 0.55 ± 0.25) than diabetic eyes without edema (mean superficial FAZ ± SD 0.41 ± 0.12) and control subjects (mean superficial FAZ ± SD 0.35 ± 0.09). Conclusion: Using OCTA machine with AngioAnalytics parameters (vessel area density and non-flow area) helped in objective quantification of macular perfusion and accurately measuring the FAZ area in diabetic eyes with macular edema. Both parameters were significantly correlated with visual function in treatment-naïve diabetic eyes with edema. These OCTA biomarkers could be used to predict visual function in such eyes, to monitor response to treatment. [ABSTRACT FROM AUTHOR]

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Purpose: Evaluation of foveal avascular zone (FAZ) in children with diabetes (DM) using OCTA. Methods: We examined 112 diabetic children without DR aged 6–18 years and 30 age-matched controls using Topcon OCT Angiography and measured FAZ in superficial (SCP) and deep capillary plexus (DCP). The study group was divided into three subgroups depending on DM duration group 1: < 5 years (n = 40), group 2: 5–10 years (n = 42), group 3: > 10 years (n = 30). Results: The mean DCP FAZ increased with DM duration from 502.2 μm2 (SD 137.8) in group 1 to 523.9 μm2 (SD 159.2) in group 2 and 539.7 μm2 (SD 189.1) in group 3. Control group differed significantly from group 1 (p = 0.0120), group 2 (p = 0.0019) and group 3 (p = 0.0011). The mean DCP to SCP FAZ surface ratio was 1.88 (SD 0.68) in the study vs 1.58 (SD 0.48) in the control group (p = 0.0232). The DCP and SCP FAZ surface difference was 217.6 μm2 (SD 100.8 μm2) in diabetics vs. 124.2 μm2 (SD 72.8 μm2) in controls (p < 0.0001). In the control group, it was significantly smaller than in group 1 (p < 0.006), group 2 (p < 0.0001) and group 3 (p < 0.0001). Conclusions: Changes can be detected in FAZ of diabetic children before DR development which can be vital for screening. [ABSTRACT FROM AUTHOR]

Purpose: To evaluate the effect of adenoidectomy on the brains of children with obstructive sleep apnea-hypopnea syndrome (OSAS) through observation of the alteration of retinal perfusion by optical coherence tomography angiography (OCTA).Methods: Sixty-two children with OSAS (124 eyes; 5.94 ± 1.64 years old; 53.2% boys) were enrolled in this study. Their retinal vascular network density indices, including vascular diameter (VD), vascular area density (VAD), vessel skeleton density (VSD), vessel perimeter index (VPI) on the macular superficial/deep capillary plexus (SCP/DCP), and the size of the foveal avascular zone (FAZ) were analyzed by OCTA before treatment and at 1 month after the adenoidectomy.Results: After the adenoidectomy, the values of VD, VAD, VSD, and VPI in the SCP/DCP of the parafovea were significantly increased (p < 0.01). The FAZ was significantly diminished in the SCP (t = 4.50, p < 0.05) and increased in the DCP (t = − 4.43, p < 0.05). The peripapillary indices in the SCP/DCP were not significantly changed (p > 0.05).Conclusion: By improvement of hypoxia, the response of the parafoveal vessels was more sensitive than that of the peripapillary region in children with OSAS. Therefore, OCTA may be an ideal method to evaluate the changes of the retinal vascular system, which could be an effective parameter for the early evaluation of adenoidectomy on cases of pediatric OSAS. [ABSTRACT FROM AUTHOR]

L’omniprésence et l’abondance des images associant en une figure dirigeants français et allemands dans les médias européens contemporains tendent à laisser penser que ce motif a toujours été là, disponible pour dire et écrire l’actualité. Pourtant, il semble peu probable qu’au sortir de la seconde guerre mondiale il en ait été de même. Dans cette perspective, l’article vise à déconstruire cet effet d’évidence en interrogeant le rôle et la place tenus par les images périodiques dans la construction et l’institution d’une figure du « vivre-ensemble » franco-allemand. Cette opération prend la forme d’une analyse socio-sémiotique : la réflexion porte à la fois sur les images — photographies et caricatures — et leurs légendes, sur leur agencement dans la page de journal et sur leurs conditions de production. La démarche procède également d’une double comparaison : en diachronie, dans un temps relativement long (de 1949 à 2012), et en synchronie, sur la base d’une confrontation de deux titres de presse quotidienne nationale de « référence », l’un français et l’autre allemand, Le Monde et la Frankfurter Allgemeine Zeitung (FAZ). Une interrogation sur les conditions de possibilité de la présence de l’image dans ces deux périodiques permet d’abord de dégager combien la place de l’imagerie franco-allemande ne va pas de soi, mais résulte d’un processus de longue haleine. Toutefois, malgré défis et obstacles, à la fois techniques et idéologiques, la figure franco-allemande s’impose par le biais de la stabilisation de modèles de représentation qui en font un motif naturel et incontournable. Ainsi, des cadres éditoriaux pérennes favorisent son implantation et sa reconnaissance au quotidien. À l’intérieur de ces cadres, à la surface des images, la figuration de la ressemblance et de la proximité entre les dirigeants français et allemands contribue à forger la représentation d’une indéfectible unité binationale. Tout comme le fait l’actualisation continue d’un motif européen donné à voir à leurs côtés. Media images depicting French and German leadership as a “fellowship” (omnipresent and abundant as they are) tend to convey the impression that this portrayal has always existed, and are readily available as an endorsement in the rendering of news. And yet, it hardly seems likely that this would have been the case at the close of the Second World War. This article aims to deconstruct this presupposition by examining the function and importance of media images in the construction and implementation of Franco-German “fellowship” by way of a socio-semiotic analysis of both the images (photos and political cartoons) and their legends, page location, and conditions of production. The analysis is two-pronged: the first aspect, diachronic, spans a relatively long period (1949-2012); the second, synchronic, is based on the confrontation between two notable national dailies in France and Germany: Le Monde and the Frankfurter Allgemeine Zeitung (FAZ). An analysis of the conditions enabling the presence of the depiction in these two periodicals demonstrates how this Franco-German image is not self-evident, but rather the result of a long and drawn-out process. And despite challenges and obstacles, both technical and ideological, the Franco-German image still manages to impose itself through the stabilizing effect of representational models which render it natural and unavoidable. Thus, entrenched editorial frameworks encourage its establishment and recognition on a daily basis. Within these frameworks, on the image surface, the depiction of similarity and harmony between French and German leaders helps forge the appearance of an unwavering binational unity, aided by the inevitable presence of the European logo at their side. A onipresença e a abundância de imagens que associam dirigentes franceses e alemães nos meios de comunição europeus dá a impressão de que essa parceria sempre existiu e que se tratava de uma realidade a ser endossada e retratada pelas notícias. No entanto, é pouco provável, ao final da Segunda Guerra Mundial, que isso fosse acontecer. Nessa perspectiva, este artigo busca desconstruir esse “efeito de evidência”, interrogando o papel e o lugar ocupado pelas imagens periódicas na construção e na instituição de uma “convivência” franco-alemã. Para isso, será realizada uma análise socio-semiótica: uma reflexão que deve tratar dar imagens – fotografias e caricaturas –, das legendas, do seu agenciamento na página do jornal e de suas condições de produção. A análise também propõe uma dupla comparação: uma diacrônica, aplicada a um período relativamente longo (de 1949 à 2012); e a outra sincrônica, feita a partir de uma confrontaçãoentre dois veículos da imprensa nacional de “referência”, um francês e uma alemão, Le Monde e Frankfurter Allgemeine Zeitung (FAZ). Um questionamento sobre as condições que possibilitam a presença da imagem nesses dois periódicos permite ainda perceber em que sentido o lugar ocupado pelas imagens franco-alemãs não resulta do acaso, mas de um processo mais longo. Contudo, apesar dos desafios e obstáculos, técnicos e também ideológicos, o retrato franco-alemão se impõe pelo viés da estabilização de modelos de representação que fazem dessa imagem uma causa natural e incontornável. Dessa forma, enquadramentos editoriais perenes favorecem sua implantação e reconhecimento no quotidianodos leitores. No interior dessas quadros, na superfície das imagens, a figuração da semelhança e da proximidade entre os dirigentes franceses e alemães contribui para forjar a apresentação de um indefectível unidade binacional. Soma-se a isso o fato delas se situarem a favor de uma atualização contínua da causa europeia.

The flagellum and flagellum attachment zone (FAZ) are important cytoskeletal structures in trypanosomatids, being required for motility, cell division and cell morphogenesis. Trypanosomatid cytoskeletons contain abundant high molecular mass proteins (HMMPs), but many of their biological functions are still unclear. Here, we report the characterization of the giant FAZ protein, FAZ10, in Trypanosoma brucei, which, using immunoelectron microscopy, we show localizes to the intermembrane staples in the FAZ intracellular domain. Our data show that FAZ10 is a giant cytoskeletal protein essential for normal growth and morphology in both procyclic and bloodstream parasite life cycle stages, with its depletion leading to defects in cell morphogenesis, flagellum attachment, and kinetoplast and nucleus positioning. We show that the flagellum attachment defects are probably brought about by reduced tethering of the proximal domain of the paraflagellar rod to the FAZ filament. Further, FAZ10 depletion also reduces abundance of FAZ flagellum domain protein, ClpGM6. Moreover, ablation of FAZ10 impaired the timing and placement of the cleavage furrow during cytokinesis, resulting in premature or asymmetrical cell division. [ABSTRACT FROM AUTHOR]

A defining feature of Trypanosoma brucei cell shape is the lateral attachment of the flagellum to the cell body, mediated by the flagellum attachment zone (FAZ). The FAZ is a complex cytoskeletal structure that connects the flagellum skeleton through two membranes to the cytoskeleton. The FAZ acts as a ‘cellular ruler’ of morphology by regulating cell length and organelle position and is therefore critical for both cell division and life cycle differentiations. Here we provide an overview of the advances in our understanding of the composition, assembly, and function of the FAZ. [ABSTRACT FROM AUTHOR]

Dado um grafo orientado G, uma cobertura é um subconjunto B de arestas que interceptam todos os cortes de G. De maneira equivalente, a contração das arestas de B tornam o grafo G fortemente conexo. Um algoritmo primal-dual de complexidade O(n5) é apresentado por Frank (1981), este algoritmo encontra uma cobertura mínima do grafo orientado. No caso de um grafo planar, o problema dual será encontrar um conjunto mínimo de arestas cuja remoção torna G acíclico. Neste trabalho será mostrado como utilizar o algoritmo de Frank para resolver o problema dual. Será também apresentado uma melhoria que torna o algoritmo de Frank mais eficiente em casos práticos.

To evaluate epidemiology of retinal and choroidal diseases and to calculate the Foveal Avascular Zone(FAZ), diameter and its variation with different diseases and analyse its impact on BCVA(Best corrected visual acuity) using Fundus fluorescein Angiography as diagnostic tool. Materials and methods: The study was conducted in 100cases of retinal and choroidalpathologies undergoing FFA Out of 100 patients maximum were in the age group 50-60 yrs with Diabetic Retinopathy as maximum incidence. FAZ in within normal eyes were in the range of 0.400mm-0.500mm while it increased in Diabetic retinopathy, BRVO,CRAO and hypertensive retinopathy. Eyes with larger FAZ had lower BCVA [ABSTRACT FROM AUTHOR]

The retinal vasculature is an extremely complex system that is adapted to support the metabolic demands of the retinal structures, but on the other hand maintain the optimal optical qualities of this tissue. Through histological studies and clinical studies using fluorescein angiography we have learned a lot about the retinal vasculature in its physiological state and in different diseases, but both of these study methods have serious limitations that limit their extensive application in healthy subjects or in patients with early disease. In this current review we will present early observations about the retinal vasculature from several novel noninvasive imaging modalities like adaptive optics SLO, retinal functional imager, adaptive optics OCT and Doppler OCT. Some of these instruments allow a more detailed in vivo examination of the retinal vasculature than fluorescein angiography without its potentially serious side effects, thus better allowing us to further study retinal vascular homeostasis in healthy subjects and to identify preclinical changes in early disease stages. [ABSTRACT FROM AUTHOR]

Polo-like kinases play an important role in a variety of mitotic events in mammalian cells, ranging from centriole separation and chromosome congression to abscission. To fulfill these roles, Polo-like kinase homologs move to different cellular locations as the cell cycle progresses, starting at the centrosome, progressing to the spindle poles and then the midbody. In the protist parasite Trypanosoma brucei, the single polo-like kinase homolog T. brucei PLK (TbPLK) is essential for cytokinesis and is necessary for the correct duplication of a centrin-containing cytoskeletal structure known as the bilobe. We show that TbPLK has a dynamic localization pattern during the cell cycle. The kinase localizes to the basal body, which nucleates the flagellum, and then successively localizes to a series of cytoskeletal structures that regulate the position and attachment of the flagellum to the cell body. The kinase localizes to each of these structures as they are duplicating. TbPLK associates with a specialized set of microtubules, known as the microtubule quartet, which might transport the kinase during its migration. Depletion of TbPLK causes defects in basal body segregation and blocks the duplication of the regulators that position the flagellum, suggesting that its presence on these structures might be necessary for their proper biogenesis. TbPLK migrates throughout the cell in T. brucei, but the specific locations to which it targets and its functions are geared towards the inheritance of a properly positioned and attached flagellum. [ABSTRACT FROM AUTHOR]

Abstract: The flagellar pocket and the cytostome are surface domains of Trypanosoma cruzi epimastigote involved in acquisition of nutrients. The cytostome is physically connected to the flagellar complex. To investigate if this association plays a role in endocytosis in T. cruzi, the endocytic activity in wild type and gp72 null mutant (flagellum-cell body attachment region is absent) epimastigotes was compared. Both wild type and mutant cells were incubated with transferrin conjugated with Alexa 543 or gold particles over different time periods and thereafter qualitatively and quantitatively analyzed by flow cytometry and transmission electron microscopy. Flow cytometry analysis showed a reduction in transferrin uptake by null mutant after 30min of incubation. In addition, at this time period, signals detected by fluorescence microscopy were slightly lower in null mutant cells. At lower incubation times, no differences between wild type and mutant epimastigotes could be observed. Quantitative data obtained by morphometric and flow cytometry analysis suggested that the speed of the endocytic process in the null mutant was similar to wild type cells, although null mutants were not able to bind cargo and therefore internalize as much as wild type epimastigotes. Our observations suggest that the physical association between cytostome and the flagellar complex plays a role in endocytosis efficiency by epimastigotes of T. cruzi. [ABSTRACT FROM AUTHOR]