scholarly journals 2D alpha-shapes to quantify retinal microvasculature morphology and their application to proliferative diabetic retinopathy characterisation in fundus photographs

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Emma Pead ◽  
Ylenia Giarratano ◽  
Andrew J. Tatham ◽  
Miguel O. Bernabeu ◽  
Baljean Dhillon ◽  
...  
Keyword(s):  
Diabetic Retinopathy ◽  
Proliferative Diabetic Retinopathy ◽  
Imaging Biomarkers ◽  
Cross Sectional ◽  
Vascular Abnormalities ◽  
Small Vessels ◽  
Alpha Shapes ◽  
Retinal Microvasculature ◽  
Fundus Photographs ◽  
Sectional Analysis

AbstractThe use of 2D alpha-shapes (α-shapes) to quantify morphological features of the retinal microvasculature could lead to imaging biomarkers for proliferative diabetic retinopathy (PDR). We tested our approach using the MESSIDOR dataset that consists of colour fundus photographs from 547 healthy individuals, 149 with mild diabetic retinopathy (DR), 239 with moderate DR, 199 pre-PDR and 53 PDR. The skeleton (centrelines) of the automatically segmented retinal vasculature was represented as an α-shape and the proposed parameters, complexity ($${Op\alpha }_{min}$$ O p α min ), spread (OpA), global shape (VS) and presence of abnormal angiogenesis (Gradα) were computed. In cross-sectional analysis, individuals with PDR had a lower $${Op\alpha }_{min}$$ O p α min , OpA and Gradα indicating a vasculature that is more complex, less spread (i.e. dense) and the presence of numerous small vessels. The results show that α-shape parameters characterise vascular abnormalities predictive of PDR (AUC 0.73; 95% CI [0.73 0.74]) and have therefore potential to reveal changes in retinal microvascular morphology.

scholarly journals Retinal microvascular parameters are not associated with diabetes in the Northern Ireland Cohort for the Longitudinal Study of Ageing

2021 ◽  
Author(s):  
Rachael Ann O’Neill ◽  
Alexander Peter Maxwell ◽  
Frank Kee ◽  
Ian Young ◽  
Bernadette McGuinness ◽  
...  
Keyword(s):  
Longitudinal Study ◽  
Northern Ireland ◽  
Glycated Haemoglobin ◽  
Haemoglobin A1c ◽  
Cross Sectional ◽  
Non Invasive ◽  
Retinal Microvasculature ◽  
Diabetes Status ◽  
Automated Software ◽  
Sectional Analysis

Abstract Background The retinal microvasculature offers unique non-invasive evaluation of systemic microvascular abnormalities. Previous studies reported associations between retinal microvascular parameters (RMPs) and diabetes. The aim of this study was to assess associations between RMPs and diabetes in a cross-sectional analysis of older persons from the Northern Ireland Cohort for the Longitudinal Study of Ageing (NICOLA). Methods RMPs (central retinal arteriolar/venular equivalents, arteriolar to venular ratio, fractal dimension, and tortuosity) were measured from optic disc-centred fundus images using semi-automated software. Associations were assessed between RMPs and diabetes status with adjustment for potential confounders. Results Data were included for 1762 participants with 209 classified as having diabetes. Participants had a mean age of 62.1 ± 8.5 years, and 54% were female. As expected, participants with diabetes had significantly higher mean glycated haemoglobin A1c compared to participants without diabetes (57.4 ± 17.6 mmol/mol versus 37.0 ± 4.2 mmol/mol, respectively). In unadjusted and minimally adjusted regression, arteriolar to venular ratio, arteriolar tortuosity and venular tortuosity were significantly associated with diabetes (minimally adjusted odds ratio [OR] = 0.85; 95% confidence intervals [CIs] 0.73, 0.99; P = 0.04, OR = 1.18; 95% CI 1.02, 1.37; P = 0.03 and OR = 1.20; 95% CI 1.04, 1.38; P = 0.01, respectively), although all failed to remain significant following adjustment for potential confounders. No additional associations between other RMPs and diabetes were detected. Conclusion Despite previously reported associations between diabetes and RMPs, our study failed to corroborate these associations in an older community-based cohort.

scholarly journals Parafoveal OCT Angiography Features in Diabetic Patients without Clinical Diabetic Retinopathy: A Qualitative and Quantitative Analysis

2017 ◽  
Vol 2017 ◽  
pp. 1-14 ◽  
Author(s):  
Mathilde M. Goudot ◽  
Anne Sikorav ◽  
Oudy Semoun ◽  
Alexandra Miere ◽  
Camille Jung ◽  
...  
Keyword(s):  
Diabetic Retinopathy ◽  
Quantitative Analysis ◽  
Capillary Density ◽  
Oct Angiography ◽  
Foveal Avascular Zone ◽  
Diabetic Patients ◽  
Cross Sectional ◽  
The Mean ◽  
Fundus Photographs ◽  
And Gender

Purpose. To evaluate the capacity of OCT angiography (OCTA) for detecting infraclinical lesions in parafoveal capillaries in diabetic patients without diabetic retinopathy (DR). Methods. This prospective observational cross-sectional case-control study analyzed the superficial and deep capillary plexuses (SCP and DCP) on macular OCTA scans (3 × 3 mm) centered on the fovea. We compared 22 diabetic patients (34 eyes included) without DR diagnosis on color fundus photographs, with 22 age- and gender-matched nondiabetic controls (40 eyes included). Qualitative analysis concerned morphological ischemic capillary alterations. Quantitative analysis measured foveal avascular zone (FAZ) size, parafoveal capillary density, and enlargement coefficient of FAZ between SCP and DCP. Results. Neither the qualitative nor quantitative parameters were significantly different between both groups. No microaneurysms or venous tortuosity was observed in any of the analyzed images. On the SCP, the mean FAZ area was 0.322 ± 0.125 mm2 in diabetic patients and 0.285 ± 0.150 mm2 in controls, P=0.31. On the DCP, the mean FAZ area was 0.444 ± 0.153 mm2 in cases and 0.398 ± 0.138 mm2 in controls, P=0.20. Conclusion. OCTA did not detect infraclinical qualitative or quantitative differences in parafoveal capillaries of diabetic patients without DR in comparison with nondiabetic controls.

scholarly journals Stringent glycemic control is still the key to evade diabetic retinopathy.

2020 ◽  
Vol 27 (05) ◽  
pp. 1011-1016
Author(s):  
Syed Munawar Alam ◽  
Sagheer Ahmed ◽  
Shazia Bano ◽  
Shahneela Perveen
Keyword(s):  
Diabetic Retinopathy ◽  
Glycemic Control ◽  
Proliferative Diabetic Retinopathy ◽  
Study Groups ◽  
Hplc Method ◽  
P Value ◽  
Diabetic Patients ◽  
Type 2 Diabetic Patients ◽  
Cross Sectional ◽  
Institutional Review

Objectives: The aim of this study was to evaluate the major determinants of diabetic retinopathy. Study Design: Cross sectional, case control study. Setting: Department of Biochemistry, Basic Medical Sciences Institute, Jinnah Post Graduate Medical Centre, Karachi. Period: March 2015 to April 2016. Material & Methods: Ethical approval was taken from the Institutional Review Board of JPMC. A total of 208 people including type 2 diabetic patients and healthy control subjects; of male gender, aged between ≥30 years and ≤ 60 years were recruited and assigned to four study groups. Each group comprise of 52 individuals, depending on the ophthalmoscopy findings, i.e. healthy controls, diabetic without retinopathy (NDR), diabetic with non-proliferative diabetic retinopathy (NPDR) and diabetic with proliferative diabetic retinopathy (PDR). Fasting blood sugar was estimated using GOD-PAP method, while HbA1c was estimated by HPLC method. Data was analyzed on SPSS software version 16. Results: Diabetics with Diabetic Retinopathy had a poor glycemic control as compare to Diabetics without Diabetic Retinopathy (FBS; 109.12 ± 13.81 vs. 184.29 ± 40.07 vs. 188.6 ± 47.68 vs. 217.06 ± 62.33; p-value = 0.001) (HbA1c; 6.73 ± 0.56 vs. 8.40 ± 1.77 vs. 9.71 ± 1.85 vs. 14.91 ± 3.87; p-value = 0.001). For Diabetic Retinopathy the odds ratio of glycemic control i.e. FBS was observed as 1.019 & HbA1c was recorded as 1.561; which was statistically significant. Conclusion: Glycemic indicators; including FBS and HbA1c, are found to be the major determinants of Diabetic Retinopathy in our study.

scholarly journals Quantifying vascular density and morphology using different swept-source optical coherence tomography angiographic scan patterns in diabetic retinopathy

2018 ◽  
Vol 103 (2) ◽  
pp. 216-221 ◽  
Author(s):  
Takao Hirano ◽  
Jyunya Kitahara ◽  
Yuichi Toriyama ◽  
Hirotsugu Kasamatsu ◽  
Toshinori Murata ◽  
...  
Keyword(s):  
Optical Coherence Tomography ◽  
Diabetic Retinopathy ◽  
Characteristic Curve ◽  
Vascular Density ◽  
Optical Coherence ◽  
Image Size ◽  
Healthy Individuals ◽  
Cross Sectional ◽  
Swept Source ◽  
Retinal Microvasculature

AimsTo evaluate quantitative metrics of the retinal microvasculature in eyes with diabetic retinopathy (DR) using various en face swept-source optical coherence tomography angiography (SS-OCTA) image sizes.MethodsNon-segmented and segmented images were acquired using an SS-OCTA device (PLEX Elite 9000; Carl Zeiss Meditec, Dublin, California, USA). The scanning protocols included the 3×3 mm, 6×6 mm and 12×12 mm fields of view. Quantitative analysis of the perfusion density (PD), vessel length density (VLD) and fractal dimension (FD) was performed. The area under the receiver operating characteristic curve was estimated to assess the ability of each image size to predict DR.ResultsThis prospective, cross-sectional study included 60 eyes, (non-DR, 13 eyes; non-proliferative DR (NPDR), 24 eyes; proliferative DR (PDR), 23 eyes) of 46 patients with diabetes and 21 eyes of 16 healthy individuals. In the 12×12 mm images, the PD of healthy individuals was significantly greater than that of patients with NPDR or PDR for all layers (NPDR, p<0.05; PDR, p<0.001 0.001; FD, p<0.001) or PDR (VLD, p<0.001; FD, p<0.001 for all layers). The results were similar for the 3×3 mm and 6×6 mm images. Overall, PD, VLD and FD progressively decreased with worsening DR severity in segmented and non-segmented layers for all SS-OCTA scan sizes. For detecting DR, 3×3 mm images best predicted DR for all evaluated quantitative parameters.ConclusionsVascular changes in DR can be monitored in detail through quantitative evaluations that combine different SS-OCTA scan sizes and parameters.

scholarly journals Blindness Registers as Epidemiological Tools for Public Health Planning: A Case Study in Belize

2014 ◽  
Vol 2014 ◽  
pp. 1-8 ◽  
Author(s):  
Sally L. Baxter ◽  
Richard P. Wormald ◽  
Joan M. Musa ◽  
Daksha Patel
Keyword(s):  
Public Health ◽  
Diabetic Retinopathy ◽  
Health Planning ◽  
Population Based ◽  
Service Planning ◽  
Cross Sectional ◽  
Screening Programs ◽  
Surgical Services ◽  
Public Health Planning ◽  
Sectional Analysis

For public eye health programs, blindness registers can be an important tool for informing service planning. This study examines how the Belize Council for the Visually Impaired (BCVI) used its blindness register data to drive several public health interventions. Cross-sectional analysis was performed for all active registrants (n=1194) to determine the distribution of causes of registration according to age, sex, and geographical district. Cataract was the leading cause of registration (39.6%), followed by glaucoma (20.8%), diabetic retinopathy (10.2%), and childhood blindness (9.4%). The distribution of the causes of registration was fairly similar between men and women and across the various districts. However, in Stann Creek, whose population is largely of African descent, glaucoma exceeded cataract. For most causes, the majority of registrants were registered at age 50 or older. Follow-up was conducted four years later. Several interventions had been initiated, most notably bolstering cataract surgical services and creating screening programs for glaucoma and diabetic retinopathy. The register itself was also improved to maximize its utility for future use. While standardized surveys may be the most appropriate method of estimating population-based measures such as prevalence or incidence, the blindness register is still a valuable source of data for public health planning.

scholarly journals Etiology of vitreous hemorrhage in a tertiary eye care center in Nepal

1970 ◽  
Vol 2 (2) ◽  
pp. 121-126 ◽  
Author(s):  
R Sharma ◽  
SN Joshi ◽  
JK Shrestha
Keyword(s):  
Diabetic Retinopathy ◽  
Retinal Vein Occlusion ◽  
Proliferative Diabetic Retinopathy ◽  
Branch Retinal Vein Occlusion ◽  
Care Center ◽  
Retinal Vasculitis ◽  
Vitreous Hemorrhage ◽  
Cross Sectional ◽  
Vein Occlusion ◽  
The Mean

Introduction: Vitreous hemorrhage is one of the most common differential diagnoses of sudden painless decrease in vision. Objective: To find out the etiology of vitreous hemorrhage in cases of vitreous hemorrhage at a tertiary eye centre in Nepal. Materials and methods: This was a hospital-based cross-sectional study done over a period of one-and-a-half years. One hundred and one subjects with vitreous hemorrhage were evaluated in detail to establish the etiology. Statistics: The mean value and standard deviation were calculated. The data were analyzed using microsoft excel and SPSS 11.5 program. Results: A total of 122 eyes of 101 patients were evaluated. The mean age was 41.90 (± 21.50) years with a range of 2 months to 84 years. Male were 73 %. Bilateral involvement was found in 20.8 %. Proliferative diabetic retinopathy, retinal vasculitis, branch retinal vein occlusion, rhegmatogenous retinal detachment together with ocular trauma constituted the etilogoy of vitreous hemorrhage in more than 75 % of patients. Conclusion: Proliferative diabetic retinopathy, retinal vasculitis and branch retinal vein occlusion are the most common causes of vitreous hemorrhage in adults whereas in children trauma is the commonest cause. Keywords: vasculitis; vitreous hemorrhage; diabetic retinopathy; Eales disease DOI: 10.3126/nepjoph.v2i2.3718 Nep J Oph 2010;2(2) 121-126

scholarly journals Bias and unclear outcomes in clinical trials of diabetic retinopathy: a cross-sectional analysis of literature

2021 ◽  
Vol 3 ◽  
Author(s):  
Vania Mozetic ◽  
Valéria Mozetic de Barros ◽  
Lucas Denadai ◽  
Matheus Ferreira Santos da Cruz ◽  
Natasha Ferreira Santos da Cruz ◽  
...  
Keyword(s):  
Clinical Trials ◽  
Diabetic Retinopathy ◽  
Adverse Events ◽  
Publication Bias ◽  
Randomized Clinical Trials ◽  
Cross Sectional ◽  
Know How ◽  
The Past ◽  
Sectional Analysis ◽  
Subjective Outcomes

BACKGROUND: Clinical trials are well-designed papers that aim to answer questions in the real world. However, sometimes they present missing, dubious and unclear outcomes that make it difficult to apply in practice. OBJECTIVE: The objective of this work is to evaluate the way and the frequency with which the outcomes in randomized clinical trials of intervention in diabetic retinopathy can be presented in an unclear way to readers. Make an analysis of how these dubious presentations can lead to misinterpretations, why this happens and how they can be remedied. METHODS AND MATERIALS: We conducted a search for RCT about DR intervention in PubMed published over the past five years. RESULTS: Seventy RCT were included, 27 in peripheral diabetic retinopathy (PDR) and 43 in diabetic macular edema (DME). In the DME group we found 25.6% reporting and publication bias; 34.9% subjective outcomes, 44.1% presented a lack of presentation of the baseline and 51.1% underreporting adverse events. In the PDR group we found 29.6% reporting and publication bias; 44.4% subjective outcomes, 14.8% presented a lack of presentation of the baseline and 62.9% underreporting adverse events. CONCLUSION: In addition to the result bias, we found other forms of publication of unclear outcomes in RCT on DR. Most of them occurred due to disrespect for CONSORT parameters. The reader must be attentive to recognize them and know how they can influence the interpretation of the data.

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