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1.
NEW BIOMARKER QUANTIFYING THE EFFECT OF ANTI-VEGF THERAPY IN EYES WITH PROLIFERATIVE DIABETIC RETINOPATHY ON ULTRAWIDE FIELD FLUORESCEIN ANGIOGRAPHY: RECOVERY Study.
Fan, W, Nittala, MG, Wykoff, CC, Brown, DM, Uji, A, Hemert, JV, Fleming, A, Robertson, G, Sadda, SR, Ip, M
Retina (Philadelphia, Pa.). 2022;(3):426-433
Abstract
PURPOSE To quantify changes of the retinal vascular bed area (RVBA) in mm2 on stereographically projected ultrawide field fluorescein angiography images in eyes with proliferative diabetic retinopathy after antivascular endothelial growth factor injection. METHODS This is a prospective, observational study. The early-phase ultrawide field fluorescein angiography images (Optos 200Tx) of 40 eyes with proliferative diabetic retinopathy and significant nonperfusion obtained at baseline and after six months (NCT02863354) were stereographically projected by correcting peripheral distortion. The global retinal vasculature on ultrawide field fluorescein angiography was extracted for calculating RVBA by summing the real size (mm2) of all the pixels automatically. RESULTS For the entire cohort, the global RVBA for the entire retina decreased from 67.1 ± 15.5 to 43.6 ± 18.8 mm2 after anti-VEGF treatment at six months (P < 0.001). In the subgroup receiving monthly anti-VEGF injections, the global RVBA decreased from 68.7 ± 16.2 to 33.9 ± 13.3 mm2 (P < 0.001). In the subgroup receiving anti-VEGF every three months, the global RVBA decreased from 65.6 ± 15.1 to 50.8 ± 19.3 mm2 (P = 0.004). CONCLUSION RVBA seems to be a new biomarker to indicate efficiency of retinal vascular changes after anti-VEGF injection. Eyes with proliferative diabetic retinopathy and significant nonperfusion demonstrate reduced RVBA after anti-VEGF treatment.
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2.
Capillary density and caliber as assessed by optical coherence tomography angiography may be significant predictors of diabetic retinopathy severity.
Kushner-Lenhoff, S, Kogachi, K, Mert, M, Chu, Z, Shahidzadeh, A, Palejwala, NV, Wolfe, J, Itty, S, Drenser, KA, Capone, A, et al
PloS one. 2022;(1):e0262996
Abstract
PURPOSE To validate retinal capillary density and caliber associations with diabetic retinopathy (DR) severity in different clinical settings. METHODS This cross-sectional study assessed retinal capillary density and caliber in the superficial retinal layer of 3-mm OCTA scans centered on the fovea. Images were collected from non-diabetic controls and subjects with mild or referable DR (defined DR worse than mild DR) between February 2016 and December 2019 at secondary and tertiary eye care centers. Vessel Skeleton Density (VSD), a measure of capillary density, and Vessel Diameter Index (VDI), a measure of vascular caliber, were calculated from these images. Discriminatory performance of VSD and VDI was evaluated using multivariable logistic regression models predicting DR severity with adjustments for sex, hypertension, and hyperlipidemia. Area under the curve (AUC) was estimated. Model performance was evaluated in two different cohorts. RESULTS This study included 594 eyes from 385 subjects. Cohort 1 was a training cohort of 509 eyes including 159 control, 155 mild non-proliferative DR (NPDR) and 195 referable DR eyes. Cohort 2 was a validation cohort consisting of 85 eyes including 16 mild NPDR and 69 referable DR eyes. In Cohort 1, addition of VSD and VDI to a model using only demographic data significantly improved the model's AUC for discrimination of eyes with any DR severity from controls (0.91 [95% CI, 0.88-0.93] versus 0.80 [95% CI, 0.76-0.83], p < 0.001) and eyes with referable DR from mild NPDR (0.90 [95% CI, 0.86-0.93] versus 0.69 [95% CI, 0.64-0.75], p < 0.001). The transportability of this regression model was excellent when implemented in Cohort 2 for the referable DR versus mild NPDR comparison. The odds ratio of having any DR compared to control subjects, and referable DR compared to mild DR decreased by 15% (95% CI: 12-18%), and 13% (95% CI: 10-15%), respectively, for every 0.001 unit increase in VSD after adjusting for comorbidities. CONCLUSION OCTA-derived capillary density has real world clinical value for rapidly assessing DR severity.
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3.
A MULTITASK DEEP-LEARNING SYSTEM FOR ASSESSMENT OF DIABETIC MACULAR ISCHEMIA ON OPTICAL COHERENCE TOMOGRAPHY ANGIOGRAPHY IMAGES.
Yang, D, Sun, Z, Shi, J, Ran, A, Tang, F, Tang, Z, Lok, J, Szeto, S, Chan, J, Yip, F, et al
Retina (Philadelphia, Pa.). 2022;(1):184-194
Abstract
PURPOSE We aimed to develop and test a deep-learning system to perform image quality and diabetic macular ischemia (DMI) assessment on optical coherence tomography angiography (OCTA) images. METHODS This study included 7,194 OCTA images with diabetes mellitus for training and primary validation and 960 images from three independent data sets for external testing. A trinary classification for image quality assessment and the presence or absence of DMI for DMI assessment were labeled on all OCTA images. Two DenseNet-161 models were built for both tasks for OCTA images of superficial and deep capillary plexuses, respectively. External testing was performed on three unseen data sets in which one data set using the same model of OCTA device as of the primary data set and two data sets using another brand of OCTA device. We assessed the performance by using the area under the receiver operating characteristic curves with sensitivities, specificities, and accuracies and the area under the precision-recall curves with precision. RESULTS For the image quality assessment, analyses for gradability and measurability assessment were performed. Our deep-learning system achieved the area under the receiver operating characteristic curves >0.948 and area under the precision-recall curves >0.866 for the gradability assessment, area under the receiver operating characteristic curves >0.960 and area under the precision-recall curves >0.822 for the measurability assessment, and area under the receiver operating characteristic curves >0.939 and area under the precision-recall curves >0.899 for the DMI assessment across three external validation data sets. Grad-CAM demonstrated the capability of our deep-learning system paying attention to regions related to DMI identification. CONCLUSION Our proposed multitask deep-learning system might facilitate the development of a simplified assessment of DMI on OCTA images among individuals with diabetes mellitus at high risk for visual loss.
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4.
Analysis of Progressive Neovascularization in Diabetic Retinopathy Using Widefield OCT Angiography.
Shiraki, A, Sakimoto, S, Eguchi, M, Kanai, M, Hara, C, Fukushima, Y, Nishida, K, Kawasaki, R, Sakaguchi, H, Nishida, K
Ophthalmology. Retina. 2022;(2):153-160
Abstract
PURPOSE To document enlarged neovascularization elsewhere (NVE) quantitatively and morphologically using widefield swept-source (SS) OCT angiography (OCTA) with vitreoretinal interface (VRI) slab images. DESIGN Retrospective, observational imaging study. PARTICIPANTS The study included 46 NVE examples in 25 eyes of 21 consecutive patients who demonstrated severe proliferative diabetic retinopathy with NVE between March 2018 and June 2020 at Osaka University Hospital. METHODS All patients underwent ophthalmologic examination, including ultra-widefield fluorescein angiography and widefield SS OCTA scans. MAIN OUTCOME MEASURES We evaluated the area and the vascular density (VD) of NVE lesions detected on five 12 × 12-mm2 or two 15 × 9-mm2 SS OCTA panoramic VRI slab images obtained at the first and final visits. RESULTS At baseline, the mean NVE area on OCTA was 1.85 ± 2.81 mm2, and the VD of the NVE lesions was 73.9 ± 14.6%. At the final visit, the mean NVE area on OCTA was 2.14 ± 3.14 mm2, and the mean VD of the NVE lesions was 65.3 ± 17.1%. The average NVE size change (square millimeters per month) was associated significantly with the ischemic index (P = 0.009). Growth of NVE area was classified into 2 patterns: round (61.8%) and ramified (38.2%). The round group tended to have a larger ischemic index at baseline than the ramified group (P = 0.0375). CONCLUSIONS We quantified the size and density of NVE lesions over time. The NVE size increase was associated significantly with the severity of ischemic changes. Furthermore, the round growth pattern was correlated significantly with the ischemic index. These findings suggest that the morphologic features of NVE are associated with more severe ischemia.
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5.
Early Detection of Microvascular Impairments With Optical Coherence Tomography Angiography in Diabetic Patients Without Clinical Retinopathy: A Meta-analysis.
Zhang, B, Chou, Y, Zhao, X, Yang, J, Chen, Y
American journal of ophthalmology. 2021;:226-237
Abstract
PURPOSE To evaluate microvascular impairments with optical coherence tomography angiography (OCTA) in the eyes of diabetic patients with no diabetic retinopathy (NDR). DESIGN Systematic review and meta-analysis. METHODS The PubMed and Embase databases were comprehensively searched to identify studies comparing the microvascular changes between diabetic eyes without clinical retinopathy and healthy controls using OCTA. Data of interest were extracted and analyzed by Review Manager V.5.3 and Stata V.14.0. The weighted mean differences and their 95% confidence intervals were used to assess the strength of the association. RESULTS Forty-five cross-sectional studies involving 2241 diabetic and 1861 healthy eyes were ultimately included. OCTA unambiguously revealed that compared with the healthy control group, the NDR group manifested enlarged areas and increased perimeters of the foveal avascular zone, with decreased perfusion density (PD) in both superficial and deep capillary plexus of the macula (except parafoveal PD of the inner retina and foveal PD) and reduced radial peripapillary capillary PD. In addition, subgroup analyses according to the type of diabetes mellitus indicated that most of those differences became nonsignificant (except parafoveal PD in the deep capillary plexus) in type 1 diabetes mellitus, while in type 2 diabetes mellitus they remained statistically significant. CONCLUSION Our results suggested that retinal microvascular impairments might have occurred antecedent to clinically visible diabetic retinopathy and could be detected early by OCTA. However, those manifestations could be inconsistent according to the types of diabetes mellitus.
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6.
EXTENDED FIELD IMAGING OPTICAL COHERENCE TOMOGRAPHY ANGIOGRAPHY FOR THE STUDY OF RETINAL AND CHOROIDAL CHANGES AFTER RADIATION THERAPY FOR CHOROIDAL MELANOMA: Comparison With Wide-Field Angiography.
Preziosa, C, Corvi, F, Staurenghi, G, Pellegrini, M
Retina (Philadelphia, Pa.). 2021;(2):373-380
Abstract
PURPOSE Radiation retinopathy is a common side effect of ocular radiotherapy with no long-term effective therapy. Optical coherence tomography angiography (OCTA) and wide-field fluorescein angiography (FA) are widely used for the study of radiation maculopathy and peripheral nonperfusion, respectively. We investigated the role of extended field imaging (EFI-OCTA) for the study of retinal and choroidal alterations after radiotherapy for choroidal melanoma. METHODS Cross-sectional observational study of 20 eyes of 20 patients diagnosed with radiation retinopathy. All patients underwent a complete imaging evaluation including FA and indocyanine green angiography (ICGA) with 55° and 102° lens (Spectralis Heidelberg Engineering, Heidelberg, Germany). Optical coherence tomography angiography imaging was performed with the Zeiss PlexElite 9000 Swept Source OCTA (Carl Zeiss Meditec, Dublin, CA) using a 12 × 12-mm volume scan pattern centered on the fovea and a +20.00-diopter lens specifically designed to obtain EFI examination. The imaging methods were then compared in terms of visible field of view, extension of nonperfused areas, and vessel density. RESULTS The mean extension ratio of EFI-OCTA compared to OCTA without EFI, FA/ICGA 55° and FA/ICGA 102° was, respectively, 1.98 ± 0.02, 1.21 ± 0.01 and 0.36 ± 0.003. The mean extension of retinal and choroidal nonperfused areas evaluated by EFI-OCTA (63.03 ± 48.21 and 38.63 ± 30.83 mm2) were significantly higher than with OCTA without EFI (40.40 ± 34.87 and 24.26 ± 21.82 mm2, P < 0.001) but lower than with FA/ICGA 102° (140.7 ± 69.23 and 108.3 ± 69.51 mm2, P < 0.001). No significant differences were found between mean extension of retinal and choroidal ischemic areas measured with EFI-OCTA and FA/ICGA 55° (69.64 ± 51.92 and 47.23 ± 33.59 mm2). The mean vessel density of EFI-OCTA (retina and choroid segmentation) was significantly different compared to OCTA without EFI (P < 0.05). Retinal vessel density was negatively correlated to retinal extension of nonperfused areas (r = -0.5, P = 0.02), and choroidal vessel density was negatively correlated to choroidal nonperfused areas (r = -0.6, P = 0.003) measured with EFI-OCTA. CONCLUSION In our series, EFI-OCTA captured larger areas than OCTA without EFI and FA/ICGA with 55° lens. EFI-OCTA images showed a good definition of retinal and choroidal vascular changes after radiotherapy, suggesting a possible role of this safe and noninvasive imaging technique in the follow-up of patients with radiation retinopathy.
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7.
Obstructive sleep apnea and the retina: a review.
Nakayama, LF, Tempaku, PF, Bergamo, VC, Polizelli, MU, Santos da Cruz, NF, Bittencourt, LRA, Regatieri, CVS
Journal of clinical sleep medicine : JCSM : official publication of the American Academy of Sleep Medicine. 2021;(9):1947-1952
Abstract
CITATION This review's objective was to synthesize the literature on the repercussions of obstructive sleep apnea (OSA) in the retinal vascular system. Two independent investigators conducted a search using the MEDLINE/PubMed database using the following terms: sleep apnea syndrome, obstructive sleep apnea, retina, vascular tortuosity, central serous chorioretinopathy, diabetes mellitus, and subfoveal choroidal thickness. Patients with OSA present increased vascular tortuosity compared with patients without OSA, decreased parafoveal and peripapillary vessel density, and increased retinal vein occlusion incidence. In central serous chorioretinopathy patients and patients who are poor responders to intravitreal anti-VEGF (-vascular endothelial growth factor) treatment for macular edema, OSA is more frequent. Macular choroidal thickness alterations are controversial, and OSA may worsen diabetic maculopathy, thus being a risk factor for diabetic retinopathy, proliferative diabetic retinopathy, and macular edema. OSA is a prevalent syndrome with many systemic vascular changes. The retina and choroid are the most affected ocular structures, with primarily vascular changes. New noninvasive technologies such as optical coherence tomography and optical coherence tomography angiography could help to better understand retinal structures and help clarify the ophthalmological repercussions of OSA. CITATION Nakayama LF, Tempaku PF, Bergamo VC, et al. Obstructive sleep apnea and the retina: a review. J Clin Sleep Med. 2021;17(9):1947-1952.
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8.
Correlation of OCT Angiography Vessel Densities and the Early Treatment Diabetic Retinopathy Study Grading Scale.
Mehta, NS, Lee, JG, Gupta, L, Zhou, DB, Andrade Romo, JS, Castanos, MV, Jansen, M, Ping Chui, TY, Rosen, RB
Ophthalmology. Retina. 2021;(7):714-715
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9.
Artificial intelligence velocimetry and microaneurysm-on-a-chip for three-dimensional analysis of blood flow in physiology and disease.
Cai, S, Li, H, Zheng, F, Kong, F, Dao, M, Karniadakis, GE, Suresh, S
Proceedings of the National Academy of Sciences of the United States of America. 2021;(13)
Abstract
Understanding the mechanics of blood flow is necessary for developing insights into mechanisms of physiology and vascular diseases in microcirculation. Given the limitations of technologies available for assessing in vivo flow fields, in vitro methods based on traditional microfluidic platforms have been developed to mimic physiological conditions. However, existing methods lack the capability to provide accurate assessment of these flow fields, particularly in vessels with complex geometries. Conventional approaches to quantify flow fields rely either on analyzing only visual images or on enforcing underlying physics without considering visualization data, which could compromise accuracy of predictions. Here, we present artificial-intelligence velocimetry (AIV) to quantify velocity and stress fields of blood flow by integrating the imaging data with underlying physics using physics-informed neural networks. We demonstrate the capability of AIV by quantifying hemodynamics in microchannels designed to mimic saccular-shaped microaneurysms (microaneurysm-on-a-chip, or MAOAC), which signify common manifestations of diabetic retinopathy, a leading cause of vision loss from blood-vessel damage in the retina in diabetic patients. We show that AIV can, without any a priori knowledge of the inlet and outlet boundary conditions, infer the two-dimensional (2D) flow fields from a sequence of 2D images of blood flow in MAOAC, but also can infer three-dimensional (3D) flow fields using only 2D images, thanks to the encoded physics laws. AIV provides a unique paradigm that seamlessly integrates images, experimental data, and underlying physics using neural networks to automatically analyze experimental data and infer key hemodynamic indicators that assess vascular injury.
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10.
OPTICAL COHERENCE TOMOGRAPHY ANGIOGRAPHY FINDINGS BEFORE AND AFTER VITRECTOMY FOR MACULAR HOLES: Useful or Useless?
Savastano, A, Bacherini, D, Savastano, MC, Finocchio, L, Dragotto, F, Lenzetti, C, Moroni, R, Caporossi, T, Rizzo, S
Retina (Philadelphia, Pa.). 2021;(7):1379-1388
Abstract
PURPOSE To investigate the vascular remodeling of optical coherence tomography angiography in full-thickness macular hole surgery. METHODS This retrospective, observational case series included 33 eyes of 33 patients with a full-thickness macular hole who underwent epiretinal membrane removal. Data were collected on best-corrected visual acuity, structural B-scan optical coherence tomography, and optical coherence tomography angiography preoperatively and at 1, 3, and 6 months postoperatively. Optical coherence tomography angiography was used to assess the retinal vascular density (VD) of the superficial vascular plexus and deep vascular plexus (DVP). Vascular density was assessed using the Early Treatment Diabetic Retinopathy Study grid for the whole, inner, and outer grids. RESULTS A statistically significant correlation was found between the VD (whole, inner, and outer grids) of the superficial vascular plexus alone from baseline to 1-month postoperatively (P < 0.001). Similarly, VD was correlated from baseline to 1, 3, and 6 months postoperatively to the whole (P < 0.0005, F = 23.22), inner (P < 0.0005, F = 28.23), and outer Early Treatment Diabetic Retinopathy Study grids of DVP (P = 0.033, F = 3.49). The best-corrected visual acuity and VD were significantly correlated with the superficial vascular plexus and DVP at baseline and 6 months (P < 0.05, all correlations). The most significant correlation was observed at 6 months between best-corrected visual acuity and DVP in the whole, inner, and outer Early Treatment Diabetic Retinopathy Study grids (P < 0.001). CONCLUSION Superficial vascular plexus and DVP are affected by full-thickness macular holes, with the most significant effects being on the DVP. Full-thickness macular hole surgery leads to an improvement in the best-corrected visual acuity in many eyes and the restoration of the VD, especially of the DVP.