Retinal Microvascular Changes in COVID-19 Bilateral Pneumonia Based on Optical Coherence Tomography Angiography.
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ABSTRACT:
SUBMITTER: Kal M
PROVIDER: S-EPMC9267319 | biostudies-literature |
REPOSITORIES: biostudies-literature
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Project description:The purpose of this study was to evaluate the presence of retinal and microvascular alterations in COVID-19 patients with bilateral pneumonia due to SARS-COV-2 that required hospital admission and compare this with a cohort of age- and sex-matched controls. COVID-19 bilateral pneumonia patients underwent retinal imaging 14 days after hospital discharge with structural optical coherence tomography (OCT) and optical coherence tomography angiography (OCTA) measurements. Vessel density (VD) and foveal avascular zone (FAZ) area were evaluated in the superficial, deep capillary plexus (SCP, DCP), and choriocapillaris (CC). After exclusion criteria, only one eye per patient was selected, and 50 eyes (25 patients and 25 controls) were included in the analysis. COVID-19 patients presented significantly thinner ganglion cell layer (GCL) (p = 0.003) and thicker retinal nerve fiber layer (RNFL) compared to controls (p = 0.048), and this RNFL thickening was greater in COVID-19 cases with cotton wool spots (CWS), when compared with patients without CWS (p = 0.032). In both SCP and DCP, COVID-19 patients presented lower VD in the foveal region (p < 0.001) and a greater FAZ area than controls (p = 0.007). These findings suggest that thrombotic and inflammatory phenomena could be happening in the retina of COVID-19 patients. Further research is warranted to analyze the longitudinal evolution of these changes over time as well as their correlation with disease severity.
| S-EPMC7998142 | biostudies-literature
Project description:To quantify retinal capillary density and morphology in uveitis using spectral-domain optical coherence tomography angiography (SD-OCTA).Cross-sectional, observational study.Healthy and uveitic subjects were recruited from 2 tertiary care eye centers. Prototype SD-OCTA devices (Cirrus; Carl Zeiss Meditec, Inc, Dublin, California, USA) were used to generate 3 × 3-mm2 OCTA images centered on the fovea. Subjects were placed into 3 groups based on the type of optical microangiography (OMAG) algorithm used for image processing (intensity and/or phase) and type of retinal segmentation (automatic or manual). A semi-automated method was used to calculate skeleton density (SD), vessel density (VD), fractal dimension (FD), and vessel diameter index (VDI). Retinal vasculature was assessed in the superficial retinal layer (SRL), deep retinal layer (DRL), and nonsegmented retinal layer (NS-RL). A generalized estimating equations model was used to analyze associations between the OCTA measures and disease status within each retinal layer. A P value < .05 was accepted as significant. Reproducibility and repeatability were assessed using the intraclass correlation coefficient (ICC).The SD, VD, and FD of the parafoveal capillaries were lower in uveitic eyes compared with healthy eyes in all retinal segments. In addition, SD and VD were significantly lower in the DRL of subjects with uveitic macular edema. There was no correlation in any capillary parameters and anatomic classification of uveitis.Quantitative analysis of parafoveal capillary density and morphology in uveitis demonstrates significantly lower capillary density and complexity. SD-OCTA algorithms are robust enough to detect these changes and can provide a novel diagnostic index of disease for uveitis subjects.
| S-EPMC5115969 | biostudies-literature
Project description:A major complication of hypertension is microvascular damage and capillary rarefaction is a known complication of hypertensive end-organ damage which confers a higher risk of systemic disease such as stroke and cardiovascular events. Our aim was to study the effect of hypertension on the retinal microvasculature using non-invasive optical coherence tomography angiography (OCTA). We performed a case-control study of 94 eyes of 94 participants with systemic hypertension and 46 normal control eyes from the Singapore Chinese Eye Study using a standardized protocol to collect data on past medical history of hypertension, including the number and type of hypertensive medications and assessed mean arterial pressure. Retinal vascular parameters were measured in all eyes using OCTA. In the multivariate analysis adjusting for confounders, compared to controls, eyes of hypertensive patients showed a decrease in the macular vessel density at the level of the superficial [OR 0.02; 95% CI, 0 to 0.64; P 0.027] and deep venous plexuses [OR 0.03; 95% CI, 0 to 0.41; P 0.009] and an increase in the deep foveal avascular zone. This shows that hypertension is associated with reduced retinal vessel density and an increased foveal avascular zone, especially in the deep venous plexus, as seen on OCTA and there is a potential role in using OCTA as a clinical tool to monitor hypertensive damage and identifying at risk patients.
| S-EPMC7293289 | biostudies-literature
Project description:PURPOSE:To report 3 cases of neurofibromatosis type 1 (NF1) with choroidal nodules associated with retinal microvascular changes imaged with optical coherence tomography angiography (OCTA). METHODS:Small case series in 3 NF1 patients. OCTA examinations were performed by a trained examiner (J.J.) after pupillary dilation. A standard scan, centered over the macula measuring 6 × 6 mm and 3 × 3 mm was obtained according to the findings on standard color photography. Additional scans were obtained in the zones with microvascular abnormalities. The segmentation provided by the machine software was used. RESULTS:Corkscrew retinal vessels were observed in association with "placoid"-type choroidal nodules as shown by near-infrared reflectance imaging. In all cases, multiple lesions were found. They were second- or third-order tortuous vessels originating from the superior or inferior temporal veins. OCTA demonstrated that the tortuous venules were located in the superficial capillary plexus, and no abnormalities were found in the deep capillary plexus. DISCUSSION:Corkscrew retinal vessels are part of a spectrum of retinal microvascular alterations seen in association, sometimes overlying choroidal nodules in patients with NF1 and are visualized in the superficial capillary plexus on OCTA. We demonstrated with OCTA that they are not associated with flow loss or ischemia in the superficial and deep capillary plexus. The link between the underlying nodule remains unclear. Since neovascularization was described in choroidal ganglioneuroma, we hypothesize that corresponding secretory substances from Schwann cells, ganglion cells, or melanocytes in choroidal nodules might alter the retinal vasculature. CONCLUSION:We report on 3 cases of NF1 with choroidal nodules in association with retinal microvascular changes imaged with OCTA. OCTA demonstrated preservation of the blood flow in the deep and superficial capillary plexus of the retina. We hypothesize that angiogenic factors secreted by the underlying choroidal nodules could have an effect on the retinal vasculature. Further immunohistological studies in NF1 patients with choroidal nodules to detect angiogenic factors (such as VEGF) are necessary to confirm this hypothesis.
| S-EPMC5422752 | biostudies-literature
Project description:PURPOSE:Von Hippel-Lindau (VHL) disease is a hereditary disorder that can lead to ophthalmic manifestations, including retinal capillary hemangioma (RCH). The diagnosis of RCH is often guided by wide-field fluorescein angiography. In some cases, optical coherence tomography angiography (OCT-A) serves as a non-invasive alternative to FA. Herein, we used OCT-A to examine the macular microvasculature in patients with VHL disease. SUBJECTS:Subjects were selected from patients with a diagnosis of VHL. The control group included eyes without retinal diagnosis from patients with an episode of unilateral retinal detachment or trauma and age ≤ 50 years old. METHODS:Subjects were scanned on the Optovue RTVue-XR device to acquire 3mm x 3mm OCT-A images of the superficial (SCP) and deep capillary plexus (DCP). SCP and DCP vessel density (VD) were calculated after the images were binarized. Furthermore, for subjects with RCH, each OCT-A image was divided equally into four quadrants. SCP and DCP VD of quadrants with RCH were compared to those without RCH. T-tests were performed for statistical analysis. RESULTS:67 eyes with a history of VHL disease were included as study subjects, while 16 eyes were included as controls. Significant increases in VD were found in patients with VHL disease for both the SCP (p = 0.0441) and DCP (p = 0.0344). When comparing quadrants with associated RCH development to those without, we found no significant difference in SCP VD (p = 0.160) or DCP VD (p = 0.484). CONCLUSIONS:OCT-A can detect changes in the retinal microvasculature in the macula of patients with VHL disease. OCT-A imaging may be an additional tool for screening and early detection of patients at risk of developing ocular complications of VHL disease. Future studies should explore subtle progression on OCT-A associated with the pathogenesis and development of RCH, particularly with larger scan patterns.
| S-EPMC7032707 | biostudies-literature
Project description:Optical coherence tomography (OCT) angiography is a dye-free and non-invasive angiography which allows visualization of retinal and choroid vascular flow, enabling observation of highly permeable and three dimensional vasculature. Although OCT angiography is providing new insights in human retinal and choroidal diseases, a few studies have been reported in experimental mice. In this study, to determine the potential of OCT angiography in experimental mice, we sought to examine whether OCT angiography can detect vascular change in type I diabetic mice. To conduct age dependent analysis, 2 and 6 month old male type 1 diabetic Ins2Akita/+ and age matched C57BL/6J mice were used. OCT angiography was performed by Heidelberg Spectralis OCT Angiography Module with 30° lens + mouse adapter lens. We acquired the OCT angiography image from the peripheral nasal position. For analysis of OCT angiography images, OCT angiography positive area were used for vascular density. We analyzed vascular density from the retinal surface (inner limiting membrane) to 120 μm depth with 4 μm steps in order to correlate vascular density vs depth (N = 4 per group). Vascular density of both mouse strains demonstrated three different peaks. By comparing with the OCT image, the first peak (superficial), second peak (intermediate) and third peak (deep) were located in nerve fiber layer/ganglion cell layer, inner plexiform layer/inner nuclear layer and outer plexiform layer/outer nuclear layer, respectively. We calculated vascular density of these peaks separately. In C57BL/6J mice, the vascular density in all three layers do not show significant difference between 2- and 6-month-old. On the other hand, 6-month-old Ins2Akita/+ mice showed a significant decrease of the vascular density in all three layers compared to 2-month-old Ins2Akita/+ mice. Also, the vascular density of 6-month-old Ins2Akita/+ mice in the deep layer showed a significant decrease compared to 2- and 6-month-old C57BL/6J mice. Thus, OCT angiography successfully detects retinal vascular difference between type I diabetic mice and control mice, and age-dependent vasculature change in type I diabetic mice. The diabetic mice demonstrated reduced vascular density due to reduced density of flowing deep vessels. Importantly, we observed this difference without retinal blood leakage, hemorrhage or neovascularization. Our analysis (vascular density vs retinal depth) suggests that OCT angiography is useful for in vivo detection of retinal vasculature alteration in experimental mice.
| S-EPMC6361705 | biostudies-literature
Project description:PURPOSE:To evaluate retinal vascular changes on optical coherence tomography angiography (OCTA) in patients with macular telangiectasia type 2 (MacTel 2) and to assess their correlation with visual acuity. METHODS:Twenty-six patients (52 eyes) with MacTel 2 and 20 age-matched controls (40 eyes) were included. Fundus examinations, including fundus autofluorescence, swept-source optical coherence tomography, and OCTA, were performed. Differences in the vascular density in the fovea and parafovea, the area of the foveal avascular zone, and the diameter of the ellipsoid zone defect of the two groups were analyzed. RESULTS:The foveal vascular density of the superficial capillary plexus was significantly lower in the MacTel 2 group than in the control group (p = 0.027). The vascular density in the entire deep capillary plexus was also significantly less in the MacTel 2 group than in the control group (all p < 0.05). The mean diameter of ellipsoid-zone disruption on OCT in the MacTel 2 group was 634.6 ± 104.3 ?m. The foveal avascular zone areas of the superficial and deep capillary plexuses were significantly enlarged in the MacTel 2 group compared to those in the control group (0.45 ± 0.12 mm2 vs. 0.27 ± 0.08 mm2, p < 0.001; 0.56 ± 0.15 mm2 vs. 0.40 ± 0.14 mm2, p = 0.001). In addition, the enlarged foveal avascular zone of the superficial and deep plexus was negatively correlated with best corrected visual acuity (logMAR) in MacTel 2 patients (p = 0.013, r = -0.642 and p = 0.042, and r = -0.511, respectively). CONCLUSIONS:Retinal vascular density changes occur in the superficial fovea and in the entire deep capillary plexus of patients with MacTel 2. The enlarged foveal avascular zone areas of the superficial and deep plexuses were prominent in the MacTel 2 group, and this enlargement correlates with worsened visual acuity.
| S-EPMC7190136 | biostudies-literature
Project description:PurposeVisual impairment assessment plays a significant role in diagnosis and clinical decisions in nonfunctioning pituitary adenoma (NFPA). Retinal microvascular alterations may potentially reflect the visual impairment. The purpose of this study was to evaluate fundus microvascular alterations in patients with NFPA.MethodsComparisons of visual field, retinal structure, and microcirculation were conducted between patients with NFPA and age- and sex-matched healthy controls. Multivariate regression modeling was used to assess the relationship between symptom duration, sellar mass size, and fundus vessel density (VD) of patients. Receiver operating characteristic (ROC) curves were depicted to determine the diagnostic performance of significant parameters to discriminate eyes with NFPA from healthy eyes.ResultsForty eyes of patients and 40 eyes of healthy individuals were enrolled. Compared to healthy controls, patients with NFPA had a larger foveal avascular zone area and thinner ganglion cell complex thickness. The VDs of patients presented an obvious decrease in radial peripapillary capillary (RPC) and an increase in the deep capillary plexus segment of the perifoveal area. The peripapillary VDs of patients were significantly related to sellar mass size. The area under the ROC curve of VD in the RPC segment of the temporo-inferior sector was the largest (0.801; 95% confidence interval, 0.70-0.90; P < 0.001).ConclusionsThe fundus of patients with NFPA demonstrated significant and characteristic microvascular impairments. The VDs were also significantly associated with sellar mass size.Translational relevanceRetinal microvascular alterations detected by optical coherence tomography angiography are characteristic and related to sellar mass size, which may provide information that facilitates the diagnosis of NFPA.
| S-EPMC8742530 | biostudies-literature
Project description:We investigated the characteristics of microvessel tortuosity in branch retinal vein occlusion (BRVO) and central retinal vein occlusion (CRVO) and their associations with visual outcomes using optical coherence tomography angiography (OCTA). Thirty-four BRVO and 21 CRVO patients and 31 healthy subjects were included. From OCTA, the branch number (BN), mean branch length (BL), mean Euclidean length (EL), vessel density (VD) and vessel tortuosity (VT) were quantified. In BRVO eyes, compared with that in the controls, the affected area of the deep capillary plexus (DCP) showed a decreased BN and VD, an increased BL, and unchanged VT. The nonaffected area of the DCP showed decreases in BN, VD and VT. The affected area of the superficial capillary plexus (SCP) showed higher VT. In CRVO eyes, the DCP showed a lower BN, VD and VT, while the SCP showed a lower BN and greater BL and EL. Improved visual acuity (VA) after 1 year in BRVO eyes was associated with decreases in BN, BL, VD and VT in the affected area in the DCP and lower VT in the nonaffected area of the SCP; in CRVO eyes, improved VA was associated with a higher BL and EL in the DCP. VT, BL, and EL may be new microvascular markers associated with changes in VA in BRVO and CRVO.
| S-EPMC7576190 | biostudies-literature
Project description:Currently there is a shortage of biomarkers for stroke, one of the leading causes of death and disability in aging populations. Retinal vessels offer a unique and accessible "window" to study the microvasculature in vivo. However, the relationship between the retinal microvasculature and stroke is not entirely clear. To investigate the retinal microvascular characteristics in stroke, we recruited patients with stroke and age-matched control subjects from a tertiary hospital in China. The macular vessel density (VD) in the superficial capillary plexus (SCP) and deep capillary plexus (DCP), foveal avascular zone (FAZ) metrics, and optical coherence tomography angiography (OCTA) measured optic disc VD were recorded for analysis. A total of 189 patients with stroke and 195 control subjects were included. After adjusting for sex, visual acuity, systolic and diastolic blood pressure, a history of smoking, levels of hemoglobulin (HbA1c), cholesterol, and high-density lipoprotein (HDL), the macular VD of SCP and DCP in all sectors was decreased in patients with stroke. In the stroke group, the VD around the FAZ and the VD of the optic disk were lower. Logistic regression found the parafovea-superior-hemi VD of DCP > 54.53% [odds ratio (OR): 0.169] as a protective factor of stroke. Using the integration of all OCTA parameters and traditional risk factors, the area under the receiver operating characteristic (AUC) curve of distinguishing patients with stroke was 0.962, with a sensitivity of 0.944 and a specificity of 0.871. Our study demonstrates that the retinal VD is decreased in patients with stroke independently of the traditional risk factors of stroke, which may shed light on the monitoring of stroke using the retinal microvascular parameters.
| S-EPMC8078175 | biostudies-literature