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1.
Adv Exp Med Biol ; 1307: 375-389, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-32488606

RESUMO

Diabetic macular edema (DME) is the main cause of vision loss in diabetic retinopathy (DR). Although it is one of the main complications of diabetes, the pathogenesis of DME is not completely understood. The hyperglycemic state promotes the activation of multiple interlinked pathways leading to DME. Different classifications have been proposed: based on clinical features, on pathogenesis or on diagnostic tests (optical coherence tomography - OCT and fluorescin angiography - FA). The multimodal imaging allows a better analysis of the morphological features of the DME. Indeed, new inflammatory biomarkers have been identified on OCT. Also, several studies are evaluating the role of the morphological features, identified on multimodal imaging, to find new prognostic factors. Over the past decade, great progresses have been made in the management of DME. Therapeutic alternatives include intraocular injection of anti-vascular endothelial grow factor agents (anti-VEGF) and steroid molecules, focal/grid laser photocoagulation and vitreo-retinal surgery. This review is focused on the description and analysis of the current intravitreal therapeutic pharmacological strategies. Current guidelines recommend anti-VEGF as first line therapy in DME. Corticosteroids are becoming increasingly relevant blocking the inflammatory cascade and indirectly reducing VEGF synthesis.


Assuntos
Diabetes Mellitus , Retinopatia Diabética , Edema Macular , Inibidores da Angiogênese/uso terapêutico , Diabetes Mellitus/tratamento farmacológico , Retinopatia Diabética/diagnóstico por imagem , Retinopatia Diabética/tratamento farmacológico , Glucocorticoides/uso terapêutico , Humanos , Injeções Intravítreas , Edema Macular/diagnóstico por imagem , Edema Macular/tratamento farmacológico , Tomografia de Coerência Óptica
2.
J Formos Med Assoc ; 120(1 Pt 1): 165-171, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-32307321

RESUMO

PURPOSE: To develop a deep learning image assessment software VeriSee™ and to validate its accuracy in grading the severity of diabetic retinopathy (DR). METHODS: Diabetic patients who underwent single-field, nonmydriatic, 45-degree color retinal fundus photography at National Taiwan University Hospital between July 2007 and June 2017 were retrospectively recruited. A total of 7524 judgeable color fundus images were collected and were graded for the severity of DR by ophthalmologists. Among these pictures, 5649 along with another 31,612 color fundus images from the EyePACS dataset were used for model training of VeriSee™. The other 1875 images were used for validation and were graded for the severity of DR by VeriSee™, ophthalmologists, and internal physicians. Area under the receiver operating characteristic curve (AUC) for VeriSee™, and the sensitivities and specificities for VeriSee™, ophthalmologists, and internal physicians in diagnosing DR were calculated. RESULTS: The AUCs for VeriSee™ in diagnosing any DR, referable DR and proliferative diabetic retinopathy (PDR) were 0.955, 0.955 and 0.984, respectively. VeriSee™ had better sensitivities in diagnosing any DR and PDR (92.2% and 90.9%, respectively) than internal physicians (64.3% and 20.6%, respectively) (P < 0.001 for both). VeriSee™ also had better sensitivities in diagnosing any DR and referable DR (92.2% and 89.2%, respectively) than ophthalmologists (86.9% and 71.1%, respectively) (P < 0.001 for both), while ophthalmologists had better specificities. CONCLUSION: VeriSee™ had good sensitivity and specificity in grading the severity of DR from color fundus images. It may offer clinical assistance to non-ophthalmologists in DR screening with nonmydriatic retinal fundus photography.


Assuntos
Aprendizado Profundo , Retinopatia Diabética , Retinopatia Diabética/diagnóstico por imagem , Humanos , Programas de Rastreamento , Fotografação , Estudos Retrospectivos , Software , Taiwan
3.
Cesk Slov Oftalmol ; 76(3): 111-117, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33126806

RESUMO

AIM: Learn about the development and changes in foveal avascular zone (FAZ) and vascularity of retina in the surrounding zone, depending on the duration in young diabetic patients type 1 (T1DM). METHODS: As part of regular one-year examinations of young T1DM patients at the Eye Clinic of the University Hospital Královské Vinohrady in Prague (Czech Republic, EU) from January to December 2019, OCT angiography using the device Spectralis (Heidelberg Engineering) was included. Forty patients aged 18 to 30 years were examined, median 21 years. T1DM was diagnosed in childhood and lasted for more than 10 years. At the same time, a control group of forty individuals of similar age, without metabolic and other general disease was examined, normal visual acuity and physiological fundoscopic finding were obligatory. The FAZ size was evaluated in both groups (using built-in function "Draw Region"), also its shape, density decrease and change in character of vascularity of the retina was assessed. RESULTS: In the control group, the FAZ area ranged from 0.06 to 0.4 mm², with an average of 0.253 ± 0.092 mm² and a median of 0.27 mm². It was not affected by a fundamental change in its round shape and the surrounding capillary netting was regular and reasonably dense. In T1DM patients, the FAZ area was in a wider range, from 0.05 to 0.64 mm², an average of 0.300 ± 0.132 mm², and a median of 0.31 mm². The difference in FAZ across-the-board evaluation was statistically significant (p = 0, 009). Diabetic preretinopathy (DpR) was defined by the irregularity of the capillary density up to the manifestation of non-perfusion, in 61% of cases the size of the FAZ was changed. In diabetic retinopathy (DR) there was always an irregularity of the FAZ shape with its enlargement, manifestation of non-perfusion, capillary dilatation and rare microaneurysms. CONCLUSION: Changes in FAZ size corresponded to the stage of T1DM on the fundoscopic finding of the eye depending on its duration. The initial increased amount of foveal capillaries, which resulted in decreased FAZ area, was followed by a gradual decrease in capillaries and increased FAZ area, consistent with the manifestations of DpR. It was accompanied by a change in capillary density in macula to eventual non-perfusion. On the contrary, the increase in the FAZ area and its irregularity accompanied by non-perfusion of the capillary net and microaneurysms corresponded to the development of DR already.


Assuntos
Diabetes Mellitus Tipo 1 , Retinopatia Diabética , Adolescente , Adulto , Criança , República Tcheca , Diabetes Mellitus Tipo 1/complicações , Diabetes Mellitus Tipo 1/diagnóstico por imagem , Retinopatia Diabética/diagnóstico por imagem , Angiofluoresceinografia , Fóvea Central/diagnóstico por imagem , Humanos , Projetos Piloto , Vasos Retinianos/diagnóstico por imagem , Tomografia de Coerência Óptica , Adulto Jovem
4.
PLoS One ; 15(10): e0240064, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33091032

RESUMO

PURPOSE: To identify objective optical coherence tomography angiography (OCTA) parameters that characterize the spectrum of non-proliferative diabetic retinopathy (NPDR), especially those that distinguish moderate from severe NPDR. METHODS: Sixty eyes of 60 patients with treatment-naïve NPDR (mild: 21, moderate: 21, severe: 18), 23 eyes with diabetes and no retinopathy, and 24 healthy control eyes were enrolled. OCTA slabs were segmented into superficial (SCP), middle (MCP), and deep capillary plexus (DCP) and thresholded by a new method based on DCP skeletonized vessel length. The foveal avascular zone (FAZ) area, parafoveal vessel density (VD), and adjusted flow index (AFI) from all three capillary layers and the vessel length density (VLD) of the SCP were compared between each severity group, after adjusting for age and image quality. RESULTS: All vessel density markers decreased with increasing severity of NPDR. SCP VD and VLD demonstrated significant differences between eyes with diabetes with no retinopathy and mild NPDR (p = 0.001 and p < 0.001, respectively), as well as between moderate vs. severe NPDR (p = 0.004 and p = 0.009, respectively). MCP VD significantly decreased between moderate and severe NPDR (p = 0.01). AFI significantly increased in the SCP and showed a decreasing trend in the MCP and DCP with increasing NPDR severity. CONCLUSIONS: Changes in the SCP VD, SCP VLD, and MCP VD can distinguish severe NPDR from lower-risk stages. SCP changes may be more reliable due to their lower susceptibility to noise and projection artifacts. Thresholding OCTA images based on DCP skeletonized vessel length showed less variability in moderate and severe NPDR. Additional studies are warranted to validate this new thresholding method.


Assuntos
Retinopatia Diabética/diagnóstico , Angiofluoresceinografia/métodos , Vasos Retinianos/fisiopatologia , Adulto , Idoso , Área Sob a Curva , Estudos Transversais , Diabetes Mellitus Tipo 1/complicações , Diabetes Mellitus Tipo 1/patologia , Diabetes Mellitus Tipo 2/complicações , Diabetes Mellitus Tipo 2/patologia , Retinopatia Diabética/diagnóstico por imagem , Retinopatia Diabética/patologia , Olho/irrigação sanguínea , Feminino , Humanos , Processamento de Imagem Assistida por Computador , Masculino , Pessoa de Meia-Idade , Curva ROC , Vasos Retinianos/diagnóstico por imagem , Índice de Gravidade de Doença , Tomografia de Coerência Óptica
5.
Zhonghua Yan Ke Za Zhi ; 56(10): 754-760, 2020 Oct 11.
Artigo em Chinês | MEDLINE | ID: mdl-33059418

RESUMO

Objective: To study the diabetic keratopathy in type 2 diabetes patients with retinopathy by in vivo laser confocal microscopy. Methods: This was a case-control study. Ninety type 2 diabetes patients were involved in this study from May 2015 to December 2019 in Qingdao Eye Hospital. According to the diabetic retinopathy clinical stage, these patients were divided into the non-proliferative diabetic retinopathy (NPDR) group (30 cases), early stage proliferative diabetic retinopathy (PDR) group (30 cases) and intermediate to late stage PDR group (30 cases). Thirty non-diabetic healthy volunteers were included in the control group. The central cornea was observed with an in vivo laser confocal microscope. The corneal nerve fiber density, nerve fiber length, nerve branch density, and nerve fiber tortuosity were compared between groups. The corneal Langerhans cells, epithelial cells, stromal cells and endothelial cells were also compared. Results: There were more nerve fibers and branches in the control group than the other three diabetic groups. The nerve fiber length in the control group, NPDR group, early stage PDR group and intermediate to late stage PDR group was (21.55±2.57), (14.73±1.56), (11.23±1.40) and (8.02±1.33) mm/mm2, respectively, and there were statistically significant differences between the groups (F=316.17, P=0.00). In the nerve fiber density, nerve branch density and curvature, there were statistically significant differences between the groups (F=345.72, 479.46, 167.00, all P=0.00). The basal cell density in the control group, NPDR group, and two PDR groups was (5 761±303), (5 336±367), (4 146±379) and (3 658±365) cells/mm2, respectively, and there were statistically significant differences between the groups (F=234.94, P=0.00). The anterior stromal cell density in the four groups was (836±30), (727±57), (544±59) and (360±47) cells/mm2, respectively, and there were statistically significant differences between the groups (F=535.08, P=0.00). The hexagonal endothelium cell rate in the four groups was 62.0%±5.5%, 51.1%±3.7%, 40.2%±4.0% and 27.8%±3.9%, respectively, and the Langerhans cell density was (1.5±0.6), (4.2±1.3), (6.8±2.1) and (10.9±2.1) cells/mm2, respectively; there were statistically significant differences between the groups (F=342.28, 179.78, all P=0.00). There was no statistically significant difference between the groups in the corneal endothelial cell density (F=1.58, P=0.20). Conclusions: In type 2 diabetes patients with diabetic retinopathy, the corneal nerve fiber and branch density can be significantly reduced, and the density of the hexagonal corneal endothelial cells, epithelial basal cells and anterior stromal cells can also decrease. Langerhans cells may be involved in the development diabetic keratopathy. (Chin J Ophthalmol, 2020, 56: 754-760).


Assuntos
Diabetes Mellitus Tipo 2 , Retinopatia Diabética , Estudos de Casos e Controles , Diabetes Mellitus Tipo 2/complicações , Retinopatia Diabética/diagnóstico por imagem , Células Endoteliais , Humanos , Microscopia Confocal
6.
Annu Int Conf IEEE Eng Med Biol Soc ; 2020: 1560-1563, 2020 07.
Artigo em Inglês | MEDLINE | ID: mdl-33018290

RESUMO

The characteristics of diabetic retinopathy (DR) fundus images generally consist of multiple types of lesions which provided strong evidence for the ophthalmologists to make diagnosis. It is particularly significant to figure out an efficient method to not only accurately classify DR fundus images but also recognize all kinds of lesions on them. In this paper, a deep learning-based multi-label classification model with Gradient-weighted Class Activation Mapping (Grad-CAM) was proposed, which can both make DR classification and automatically locate the regions of different lesions. To reducing laborious annotation work and improve the efficiency of labeling, this paper innovatively considered different types of lesions as different labels for a fundus image so that this paper changed the task of lesion detection into that of image classification. A total of five labels were pre-defined and 3228 fundus images were collected for developing our model. The architecture of deep learning model was designed by ourselves based on ResNet. Through experiments on the test images, this method acquired a sensitive of 93.9% and a specificity of 94.4% on DR classification. Moreover, the corresponding regions of lesions were reasonably outlined on the DR fundus images.


Assuntos
Aprendizado Profundo , Diabetes Mellitus , Retinopatia Diabética , Retinopatia Diabética/diagnóstico por imagem , Fundo de Olho , Humanos , Sensibilidade e Especificidade
7.
Acta Diabetol ; 57(12): 1493-1499, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-32748176

RESUMO

AIMS: To evaluate diabetic retinopathy (DR) screening with a portable handheld smartphone-based retinal camera and telemedicine in an urban primary healthcare setting and to evaluate the learning curve for image acquisition, performed by healthcare personnel without previous experience in retinal imaging. METHODS: This was a prospective study that enrolled patients with type 2 diabetes mellitus (T2DM) followed at a primary healthcare unit in São Paulo, Brazil. After a brief training in image acquisition, there was further continuous feedback given by a retina specialist during the remote image reading process. Each patient underwent two fundus and one anterior ocular segment images per eye, after mydriasis. Patients were classified according to the need of referral. RESULTS: A total of 627 adult individuals with T2DM underwent retinal evaluation. The population was composed by 63.2% female individuals, age median of 66 years, diabetes duration 10.7 ± 8.2 years and HbA1c 7.7 ± 1.9% (61 + 20.8 mmol/mol). The most prevalent associated comorbidities were arterial hypertension (80.3%) and dyslipidemia (50.2%). Referral decision was possible in 81.2% patients. Most patients had absent or non-referable DR; the main ocular media opacity detected was cataract. After the 7th day of image acquisition, the daily rate of patients whose images allowed clinical decision was maintained above 80%. A higher HbA1c was associated with referable DR. CONCLUSIONS: A low-cost DR screening strategy with a handheld device and telemedicine is feasible and has the potential to increase coverage of DR screening in underserved areas; the possibility of mobile units is relevant for DR screening in the context of COVID-19 pandemic. Daily rate of patients whose examinations allowed clinical decision. X-axis: day of examination; Y-axis: rate (%) of patients whose examinations allowed a clinical decision.


Assuntos
Retinopatia Diabética/diagnóstico , Programas de Rastreamento/métodos , Fotografação/métodos , Retina/diagnóstico por imagem , Telemedicina/métodos , Adulto , Idoso , Brasil , Infecções por Coronavirus/epidemiologia , Diabetes Mellitus Tipo 2/complicações , Retinopatia Diabética/diagnóstico por imagem , Feminino , Humanos , Masculino , Programas de Rastreamento/instrumentação , Pessoa de Meia-Idade , Pandemias , Pneumonia Viral/epidemiologia , Prevalência , Atenção Primária à Saúde/métodos , Estudos Prospectivos , Encaminhamento e Consulta , Smartphone , Telemedicina/instrumentação
8.
Diabetes Res Clin Pract ; 167: 108361, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32745697

RESUMO

The most common microvascular complication of diabetes is diabetic retinopathy, the leading cause of blindness in adults of working age. Our understanding of the vascular changes in diabetic retinopathy was enhanced by the demonstration of fluorescein angiography (FA) in the human retina for the first time in 1961. It was subsequently integrated with digital fundoscopic imaging to become an invaluable technique in evaluation of the retinal vasculature. The recent development of OCT-angiography (OCT-A) has revolutionized the clinician's ability to examine the retinal vasculature without the need for injection of a contrast dye. By coupling OCT, which can provide noninvasive cross-sectional imaging of the central retina, with angiography in OCT-A, one can reveal retinal perfusion by allowing visualization of the depth-resolved retinal capillary plexus. OCT-A has allowed for more precise delineation of changes in the retinal microvasculature, specifically the alterations of retinal vasculature and loss of capillary perfusion from chronic microvascular occlusion in diabetic retinopathy.


Assuntos
Angiografia/métodos , Retinopatia Diabética/diagnóstico por imagem , Retinopatia Diabética/terapia , Tomografia de Coerência Óptica/métodos , Adulto , Diabetes Mellitus/diagnóstico , Diabetes Mellitus/patologia , Retinopatia Diabética/patologia , Angiofluoresceinografia/métodos , Humanos , Microvasos/diagnóstico por imagem , Pessoa de Meia-Idade , Oftalmoscopia/métodos , Retina/diagnóstico por imagem , Vasos Retinianos/diagnóstico por imagem
9.
PLoS One ; 15(6): e0233514, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32569310

RESUMO

Diabetic retinopathy (DR) is a serious retinal disease and is considered as a leading cause of blindness in the world. Ophthalmologists use optical coherence tomography (OCT) and fundus photography for the purpose of assessing the retinal thickness, and structure, in addition to detecting edema, hemorrhage, and scars. Deep learning models are mainly used to analyze OCT or fundus images, extract unique features for each stage of DR and therefore classify images and stage the disease. Throughout this paper, a deep Convolutional Neural Network (CNN) with 18 convolutional layers and 3 fully connected layers is proposed to analyze fundus images and automatically distinguish between controls (i.e. no DR), moderate DR (i.e. a combination of mild and moderate Non Proliferative DR (NPDR)) and severe DR (i.e. a group of severe NPDR, and Proliferative DR (PDR)) with a validation accuracy of 88%-89%, a sensitivity of 87%-89%, a specificity of 94%-95%, and a Quadratic Weighted Kappa Score of 0.91-0.92 when both 5-fold, and 10-fold cross validation methods were used respectively. A prior pre-processing stage was deployed where image resizing and a class-specific data augmentation were used. The proposed approach is considerably accurate in objectively diagnosing and grading diabetic retinopathy, which obviates the need for a retina specialist and expands access to retinal care. This technology enables both early diagnosis and objective tracking of disease progression which may help optimize medical therapy to minimize vision loss.


Assuntos
Retinopatia Diabética/classificação , Retinopatia Diabética/diagnóstico , Programas de Rastreamento/métodos , Retinopatia Diabética/diagnóstico por imagem , Programas de Triagem Diagnóstica , Técnicas de Diagnóstico Oftalmológico , Fundo de Olho , Humanos , Edema Macular/etiologia , Modelos Teóricos , Redes Neurais de Computação , Retina/patologia , Sensibilidade e Especificidade , Tomografia de Coerência Óptica/métodos
10.
PLoS One ; 15(6): e0234664, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32544179

RESUMO

PURPOSE: To compare quantitative changes in macular parameters in diabetic patients detected by two optical coherence tomography angiography (OCTA) instruments. METHODS: 80 phakic eyes were classified as no diabetes, diabetes without diabetic retinopathy (DR), mild non-proliferative diabetic retinopathy (NPDR), and severe NPDR or proliferative DR (PDR). OCTA was performed using devices from two manufacturers (Zeiss and Heidelberg). Superficial and deeper vascular skeleton density (SVSD, DVSD), superficial and deeper vessel area density (SVAD, DVAD), choriocapillaris flow voids (CCFV), and choroidal flow voids (CFV) were calculated. Inter-device comparisons were performed using the size comparison index (SCI) and the discrepancy index (DI). RESULTS: The two devices were inconsistent in SVSD, DVSD, DVAD, CCFV and CFV parameters (all P < 0.05). In addition, the SCI was positive for DVAD (all P < 0.001) and negative for SVSD, DVSD, CCFV and CFV in all groups (all P <0.001), except for DVSD in severe NPDR or PDR. The discrepancy index was not significantly different among groups for SVD, SPD, DVD, DPD and CFV (all P> 0.05). The mean DI of CCFV was statistically different between the four groups (P < 0.001). CONCLUSIONS: The two instruments were largely inconsistent in the measurement of macular parameters relevant to DR. The choice of imaging device can impact OCTA analytics and should be taken into account when drawing conclusions about DR-related changes.


Assuntos
Angiografia , Diabetes Mellitus/fisiopatologia , Retinopatia Diabética/diagnóstico por imagem , Olho/diagnóstico por imagem , Tomografia de Coerência Óptica/instrumentação , Angiografia/instrumentação , Angiografia/métodos , Angiografia/normas , Estudos de Casos e Controles , Complicações do Diabetes/diagnóstico por imagem , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Reprodutibilidade dos Testes , Estudos Retrospectivos , Tomografia de Coerência Óptica/métodos , Tomografia de Coerência Óptica/normas
11.
Sci Rep ; 10(1): 7788, 2020 05 08.
Artigo em Inglês | MEDLINE | ID: mdl-32385333

RESUMO

Diabetic nephropathy and retinopathy (DR) including diabetic macular edema (DME) are representative microvascular complications of diabetes. We conducted a retrospective multicenter study analyzing records from patients with DR (132 eyes in 70 patients) and end-stage renal diseases (ESRD) who underwent hemodialysis for the first time. We demonstrated that the central retinal thickness (CRT) values were significantly decreased (p < 0.0001), and the best-corrected visual acuity (BCVA) values were improved (p < 0.05) at 1, 3, 6, 9, and 12 months after hemodialysis initiation, in spite of a lack of specific ocular treatments for DME in 93.2% of eyes. We found a significant positive correlation in the rates of CRT changes between right and left eyes. The CRT reductions were greater in eyes with DME type subretinal detachment than in those with spongelike swelling and cystoid macular edema. The visual outcome gain was associated with the CRT reduction at 12 months in the eyes with good initial BCVA (≧20/50). Hemodialysis induction contributed to functional and anatomical improvements after 1 year, independently of initial laboratory values before the hemodialysis.


Assuntos
Retinopatia Diabética/patologia , Edema Macular/patologia , Biomarcadores , Retinopatia Diabética/diagnóstico por imagem , Retinopatia Diabética/etiologia , Retinopatia Diabética/terapia , Feminino , Seguimentos , Humanos , Edema Macular/diagnóstico por imagem , Edema Macular/etiologia , Edema Macular/terapia , Masculino , Pessoa de Meia-Idade , Diálise Renal/efeitos adversos , Diálise Renal/métodos , Tomografia de Coerência Óptica
12.
Sci Rep ; 10(1): 7299, 2020 04 29.
Artigo em Inglês | MEDLINE | ID: mdl-32350366

RESUMO

Diabetic macular edema (DME) refractory to anti-VEGF drugs is a socioeconomic burden. In this retrospective study, we investigated the relationship between DME remission and hyperreflective walls in foveal cystoid spaces, a novel finding on spectral domain optical coherence tomography (SD-OCT) images in DME. In a cross-sectional study, we assessed the relationship between hyperreflective walls in foveal cystoid spaces and other OCT findings in 110 eyes of 110 DME patients. Hyperreflective walls were delineated in 27 of 171 foveal cystoid spaces. Eyes with hyperreflective walls in foveal cystoid spaces had poorer visual acuity and more severe photoreceptor disruption than did those without such findings (P = 0.008 and P < 0.001, respectively). In the other longitudinal study, we evaluated the relationship between this finding and the remission in 54 eyes of 51 DME patients treated with as-needed ranibizumab injections for 24 months. Foveal cystoid spaces with hyperreflective walls were often persistent, and the cumulative rates of DME remission among eyes with and without the hyperreflective walls were 7.7% (1 eye) and 48.8% (20 eyes) at 18 months (hazard ratio, 0.092; P = 0.025). We characterized hyperreflective walls in foveal cystoid spaces and designated them as a predictor of no DME remission under ranibizumab injections.


Assuntos
Retinopatia Diabética , Resistência a Medicamentos/efeitos dos fármacos , Fóvea Central/diagnóstico por imagem , Edema Macular , Ranibizumab/administração & dosagem , Tomografia de Coerência Óptica , Adulto , Idoso , Biomarcadores , Estudos Transversais , Retinopatia Diabética/diagnóstico por imagem , Retinopatia Diabética/tratamento farmacológico , Feminino , Humanos , Edema Macular/diagnóstico por imagem , Edema Macular/tratamento farmacológico , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Fator A de Crescimento do Endotélio Vascular/antagonistas & inibidores
13.
Invest Ophthalmol Vis Sci ; 61(5): 8, 2020 05 11.
Artigo em Inglês | MEDLINE | ID: mdl-32392316

RESUMO

Purpose: The purpose of this study was to compare perfusion parameters of the parafovea with scans outside the parafovea to find an area most susceptible to changes secondary to diabetic retinopathy (DR). Methods: Patients with different DR severity levels as well as controls were included in this cross-sectional clinical trial. Seven standardized 3 × 3 mm areas were recorded with Swept Source Optical Coherence Tomography Angiography: one centered on the fovea, three were temporal to the fovea, and three nasally to the optic disc. The capillary perfusion density (PD) of the superficial capillary complex (SCC) and deep capillary complex (DCC) as well as the fractal dimension (FD) were generated. Statistical analyses were done with R software. Results: One hundred ninety-two eyes (33 controls, 51 no-DR, 41 mild DR, 37 moderate/severe DR, and 30 proliferative DR), of which 105 patients with diabetes and 25 healthy controls were included (59 ± 15 years; 62 women). Mean PD of the DCC was significantly less in patients without DR (parafovea = 0.48 ± 0.03; temporal = 0.48 ± 0.02; and nasal = 0.48 ± 0.03) compared to controls (parafovea = 0.49 ± 0.02; temporal = 0.50 ± 0.02; and nasal = 0.50 ± 0.03). With increasing DR severity, PD and FD of the SCC and DCC further decreased. Conclusions: Capillary perfusion of the retina is affected early by diabetes. PD of the DCC was significantly reduced in patients with diabetes who did not have any clinical signs of DR. The capillary network outside the parafovea was more susceptible to capillary perfusion deficits compared to the capillaries close to the fovea. Trial Registration: clinicaltrial.gov, NCT03765112, https://clinicaltrials.gov/ct2/show/NCT03765112?term=NCT03765112&rank=1.


Assuntos
Retinopatia Diabética/diagnóstico por imagem , Angiofluoresceinografia , Retina/diagnóstico por imagem , Tomografia de Coerência Óptica , Capilares/diagnóstico por imagem , Estudos Transversais , Retinopatia Diabética/fisiopatologia , Feminino , Fóvea Central/irrigação sanguínea , Fóvea Central/diagnóstico por imagem , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Retina/fisiopatologia , Vasos Retinianos/diagnóstico por imagem
15.
Sci Rep ; 10(1): 7177, 2020 04 28.
Artigo em Inglês | MEDLINE | ID: mdl-32346043

RESUMO

The ability to monitor progression of retinal vascular diseases like diabetic retinopathy in small animal models is often complicated by their failure to develop the end-stage complications which characterize the human phenotypes in disease. Interestingly, as micro-vascular dysfunction typically precedes the onset of retinal vascular and even some neurodegenerative diseases, the ability to visualize and quantify hemodynamic changes (e.g. decreased flow or occlusion) in retinal vessels may serve as a useful diagnostic indicator of disease progression and as a therapeutic outcome measure in response to treatment. Nevertheless, the ability to precisely and accurately quantify retinal hemodynamics remains an unmet challenge in ophthalmic research. Herein we demonstrate the ability to modify a commercial fundus camera into a low-cost laser speckle contrast imaging (LSCI) system for contrast-free and non-invasive quantification of relative changes to retinal hemodynamics over a wide field-of-view in a rodent model.


Assuntos
Retinopatia Diabética , Fluxometria por Laser-Doppler , Microcirculação , Vasos Retinianos , Animais , Velocidade do Fluxo Sanguíneo , Retinopatia Diabética/diagnóstico por imagem , Retinopatia Diabética/fisiopatologia , Feminino , Masculino , Camundongos , Vasos Retinianos/diagnóstico por imagem , Vasos Retinianos/fisiopatologia
16.
Invest Ophthalmol Vis Sci ; 61(4): 39, 2020 04 09.
Artigo em Inglês | MEDLINE | ID: mdl-32340031

RESUMO

Purpose: The purpose of this study was to use three-dimensional confocal microscopy to quantify the spatial patterns of capillary network alterations in nonproliferative diabetic retinopathy (NPDR). Methods: The retinal microvasculature was perfusion-labelled in seven normal human donor eyes and six age-matched donor eyes with NPDR. The peripapillary microcirculation was studied using confocal scanning laser microscopy. Capillary density and diameters of the radial peripapillary capillary plexus (RPCP), superficial capillary plexus (SCP), intermediate capillary plexus (ICP), and deep capillary plexus (DCP) were quantified and compared. Three-dimensional visualization strategies were also used to compare the communications between capillary beds and precapillary arterioles and postcapillary venules. Results: Mean capillary diameter was significantly increased in the NPDR group (P < 0.001). Intercapillary distance was significantly increased in the DCP (P = 0.004) and RPCP (P = 0.022) of the NPDR group (P = 0.010) but not the SCP (P = 0.155) or ICP (P = 0.103). The NPDR group was associated with an increased frequency of inflow communication between the SCP and ICP/DCP and a decreased frequency of communication between the SCP and RPCP (P = 0.023). There was no difference in the patterns of outflow communications between the two groups (P = 0.771). Conclusions: This study demonstrates that capillary plexuses are nonuniformly perturbed in NPDR. These structural changes may be indicative of perturbations to blood flow patterns between different retinal layers. Our findings may aid the interpretation of previous clinical observations made using optical coherence tomography angiography as well as improve our understanding of the pathogenesis of NPDR.


Assuntos
Retinopatia Diabética/diagnóstico por imagem , Retinopatia Diabética/patologia , Imageamento Tridimensional , Vasos Retinianos/patologia , Austrália , Estudos de Casos e Controles , Enucleação Ocular , Feminino , Humanos , Técnicas In Vitro , Masculino , Microcirculação/fisiologia , Microscopia Confocal/métodos , Valores de Referência , Vasos Retinianos/diagnóstico por imagem , Tomografia de Coerência Óptica/métodos
17.
Invest Ophthalmol Vis Sci ; 61(4): 38, 2020 04 09.
Artigo em Inglês | MEDLINE | ID: mdl-32340033

RESUMO

Purpose: To test the hypothesis that hyperglycemia perturbs neurovascular\ coupling and compromises retinal vascular response during transition from dark to light in healthy subjects using optical coherence tomography angiography (OCTA). Methods: Ten eyes of 10 healthy subjects were tested, first during fasting and then after receiving a 75-g oral glucose solution. In both sessions, OCTA imaging was done in the dark-adapted state and at 50 seconds, 2 minutes, 5 minutes, and 15 minutes of ambient light. Parafoveal vessel density (VD) and adjusted flow index (AFI) were calculated for the superficial capillary plexus (SCP), middle capillary plexus (MCP), and deep capillary plexus (DCP), and vessel length density was calculated for the SCP. These measurements were compared among conditions after adjusting for age, refractive error, and OCTA scan quality. Results: Hyperglycemia leads to a complete reversal of dark/light adaptation trends in VD and AFI in all layers of the inner retina. In the dark, there is significantly decreased VD in the DCP in hyperglycemia. With a transition to light in hyperglycemia, we observed decreased VD in the SCP, increased vessel density in the MCP and DCP, and decreased AFI in all three layers. Conclusions: Our results show that hyperglycemia significantly disrupts neurovascular coupling in healthy eyes, with potential metabolic deficits affecting photoreceptor oxygen demands during dark adaptation and the inner retina during light exposure. In pathological states, such as diabetic retinopathy, where the vasculature is already attenuated, retinal neurons may be exquisitely vulnerable to intermittent hyperglycemic challenge, which should be the focus of future studies.


Assuntos
Adaptação Ocular/fisiologia , Adaptação à Escuridão/fisiologia , Glucose/efeitos adversos , Hiperglicemia/complicações , Vasos Retinianos/diagnóstico por imagem , Tomografia de Coerência Óptica/métodos , Adulto , Estudos de Coortes , Retinopatia Diabética/diagnóstico por imagem , Retinopatia Diabética/fisiopatologia , Feminino , Glucose/administração & dosagem , Voluntários Saudáveis , Humanos , Modelos Lineares , Masculino , Acoplamento Neurovascular , Variações Dependentes do Observador , Estudos Prospectivos , Vasos Retinianos/patologia , Medição de Risco
18.
Invest Ophthalmol Vis Sci ; 61(4): 29, 2020 04 09.
Artigo em Inglês | MEDLINE | ID: mdl-32324858

RESUMO

Purpose: Previous studies on the association between choroidal thickness (CT) and severity of diabetic retinopathy (DR) gave conflicting results. The aim of this study was to evaluate the CT changes in diabetic patients and associated factors in a large sample of Chinese patients with diabetes. Methods: Type 2 diabetes mellitus patients without history of ocular treatment were recruited from the community health system in Guangzhou, China. The swept source OCT instrument was used to obtain high-definition retina and choroid images. The diabetic retinopathy (DR) status was graded based on the guidelines of the United Kingdom National Diabetic Eye Screening Programme. Univariate and multivariate linear regression analyses was used to explore the association of CT with DR severity, diabetic macular edema (DME), hemoglobin A1c, and vision function. Results: A total of 1347 patients were included in the final analysis. After adjusting for other factors, the patients with stage R3 DR had significantly thinner CT (ß = -29.1 µm, 95% CI -53.8 to -4.4, P = 0.021) in comparison in those with R0. After adjusting for other factors, the CTs were thicker than those in R0 patients with difference of 15.6 µm (95% CI 4.3-26.9, P = 0.007) for outer nasal sector, 15.7 µm (95% CI 3.8-25.5, P = 0.008) for outer inferior, and 12.2 µm (95% CI 0.4-24.0, P = 0.042) for inner inferior sector. The presence of DME and hemoglobin A1c levels did not significantly affect average CT. Higher average CT was significantly associated with better best corrected visual acuity, with a -0.02 LogMAR unit per 100 µm increase in average CT (95% CI -0.03 to -0.01, P < 0.001). Conclusions: CT increased in the early stage of DR, and further decreased with DR progression. DME was not significantly associated with CT. These findings provide more clues to suggest that choroid alterations play a role in the pathogenesis of DR.


Assuntos
Corioide/patologia , Diabetes Mellitus Tipo 2/complicações , Retinopatia Diabética/diagnóstico por imagem , Retina/patologia , Acuidade Visual , Adulto , Fatores Etários , Idoso , Idoso de 80 Anos ou mais , China , Corioide/diagnóstico por imagem , Estudos Transversais , Retinopatia Diabética/epidemiologia , Retinopatia Diabética/fisiopatologia , Progressão da Doença , Feminino , Angiofluoresceinografia/métodos , Hospitais Universitários , Humanos , Edema Macular/diagnóstico por imagem , Masculino , Pessoa de Meia-Idade , Retina/diagnóstico por imagem , Medição de Risco , Índice de Gravidade de Doença , Fatores Sexuais
19.
Am J Ophthalmol ; 215: 25-36, 2020 07.
Artigo em Inglês | MEDLINE | ID: mdl-32224103

RESUMO

PURPOSE: This study was performed to investigate the association between changes in retinal layer thickness and perfusion status in the extramacular areas of eyes with diabetic retinopathy. DESIGN: Retrospective cross-sectional study. METHODS: The medical records of 70 eyes from 55 patients with diabetes were reviewed. The status of retinal perfusion in extramacular areas was evaluated using swept-source optical coherence tomography angiography. Retinal layer thickness was measured in nonperfused areas (NPA) larger than 2 optic disc areas, areas of sparse capillaries (SC), and perfused areas (PA-DR) in eyes with diabetic retinopathy. Retinal layer thickness was also measured in perfused areas in eyes without diabetic retinopathy (PA-NDR), and the thicknesses were then compared. In addition, swept-source optical coherence tomography angiography images and retinal thickness maps were compared to investigate the distribution of retinal thickness changes and spatial relationships to areas of retinal perfusion. RESULTS: The inner retinal thickness in NPA was significantly thinner than the inner retinal thicknesses in SC, PA-DR, and PA-NDR (all P < .001), and the inner retinal thickness in PA-NDR and SC was significantly thinner than that in PA-DR (P = .006 and .031, respectively). In a distribution analysis of the extramacular areas, NPA spatially overlapped with areas of severe retinal thinning in all locations. Local thickening with smooth shapes and gentle borders overlapped with areas of capillary abnormalities. Neovascularization was present at sites of local thickening with irregular shapes and unnatural clear borders. CONCLUSIONS: Changes in retinal layer thickness were associated with perfusion status, suggesting that retinal thickness maps can reflect perfusion status.


Assuntos
Retinopatia Diabética/fisiopatologia , Retina/patologia , Vasos Retinianos/fisiopatologia , Adulto , Idoso , Estudos Transversais , Retinopatia Diabética/diagnóstico por imagem , Feminino , Angiofluoresceinografia , Humanos , Masculino , Pessoa de Meia-Idade , Fibras Nervosas/patologia , Fluxo Sanguíneo Regional/fisiologia , Retina/diagnóstico por imagem , Células Ganglionares da Retina/patologia , Vasos Retinianos/diagnóstico por imagem , Estudos Retrospectivos , Tomografia de Coerência Óptica
20.
Invest Ophthalmol Vis Sci ; 61(3): 20, 2020 03 09.
Artigo em Inglês | MEDLINE | ID: mdl-32181799

RESUMO

Purpose: To characterize 2-year changes occurring in neurodegeneration, edema, and capillary dropout in nonproliferative diabetic retinopathy. Methods: Two-year prospective longitudinal observational cohort of eyes/patients with type 2 diabetes using spectral domain optical coherence tomography (SD-OCT) and optical coherence tomography angiography (OCTA). Eyes were examined three times with intervals of 1 year. Thickness of the full retina and layer-by-layer measurements were used to identify edema or neurodegeneration. OCTA vessel density maps of the retina were used to identify capillary dropout. Early Treatment Diabetic Retinopathy Study (ETDRS) classification was performed using the seven-field ETDRS protocol. Results: A total of 62 eyes from 62 patients with diabetes were followed for 2 years. After verification for image quality, a total of 44 eyes from 44 patients (30% women) aged 52 to 80 years were retained for data analysis. There were 18 eyes with ETDRS grades 10 to 20, 17 eyes with ETDRS grade 35, and 9 eyes with ETDRS grades 43 to 47. During the 2-year follow-up period, there was a progressive increase in capillary dropout, whereas edema and neurodegeneration remained stable. In multivariate analysis, considering a model adjusted for age, sex, hemoglobin A1C, visual acuity, and diabetes duration, vessel density remained significantly different between Diabetic Retinopathy Severity Scale groups (Wilks' λ = 0.707; P = 0.015) showing association with disease progression. Conclusions: Capillary dropout increased in a period of 2 years in eyes with minimal, mild, and moderate diabetic retinopathy, whereas the presence of edema and neurodegeneration remained stable.


Assuntos
Diabetes Mellitus Tipo 2/complicações , Retinopatia Diabética/etiologia , Idoso , Idoso de 80 Anos ou mais , Capilares/diagnóstico por imagem , Capilares/patologia , Estudos de Casos e Controles , Retinopatia Diabética/diagnóstico por imagem , Retinopatia Diabética/patologia , Progressão da Doença , Feminino , Humanos , Estudos Longitudinais , Edema Macular/diagnóstico por imagem , Edema Macular/etiologia , Edema Macular/patologia , Masculino , Pessoa de Meia-Idade , Degeneração Neural/diagnóstico por imagem , Degeneração Neural/etiologia , Degeneração Neural/patologia , Retina/diagnóstico por imagem , Retina/patologia , Vasos Retinianos/diagnóstico por imagem , Vasos Retinianos/patologia , Índice de Gravidade de Doença , Tomografia de Coerência Óptica/métodos
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