Comparison of foveal avascular zone in diabetic retinopathy, high myopia, and normal fundus images

2020 ◽  
Author(s):  
Jothi J. Balaji ◽  
Arpit Agarwal ◽  
Rajiv Raman ◽  
Vasudevan Lakshminarayanan
Keyword(s):  
Diabetic Retinopathy ◽  
High Myopia ◽  
Foveal Avascular Zone ◽  
Fundus Images ◽  
Avascular Zone

Determination of foveal avascular zone in diabetic retinopathy digital fundus images

2010 ◽  
Vol 40 (7) ◽  
pp. 657-664 ◽  
Author(s):  
M.H. Ahmad Fadzil ◽  
Lila Iznita Izhar ◽  
Hanung Adi Nugroho
Keyword(s):  
Diabetic Retinopathy ◽  
Foveal Avascular Zone ◽  
Fundus Images ◽  
Avascular Zone

scholarly journals Diabetic Retinopathy Grading by Digital Curvelet Transform

2012 ◽  
Vol 2012 ◽  
pp. 1-11 ◽  
Author(s):  
Shirin Hajeb Mohammad Alipour ◽  
Hossein Rabbani ◽  
Mohammad Reza Akhlaghi
Keyword(s):  
Diabetic Retinopathy ◽  
Region Of Interest ◽  
Curvelet Transform ◽  
Optic Disk ◽  
Foveal Avascular Zone ◽  
Support Vector ◽  
Fundus Images ◽  
Fundus Fluorescein Angiography ◽  
Avascular Zone ◽  
Color Fundus Images

One of the major complications of diabetes is diabetic retinopathy. As manual analysis and diagnosis of large amount of images are time consuming, automatic detection and grading of diabetic retinopathy are desired. In this paper, we use fundus fluorescein angiography and color fundus images simultaneously, extract 6 features employing curvelet transform, and feed them to support vector machine in order to determine diabetic retinopathy severity stages. These features are area of blood vessels, area, regularity of foveal avascular zone, and the number of micro-aneurisms therein, total number of micro-aneurisms, and area of exudates. In order to extract exudates and vessels, we respectively modify curvelet coefficients of color fundus images and angiograms. The end points of extracted vessels in predefined region of interest based on optic disk are connected together to segment foveal avascular zone region. To extract micro-aneurisms from angiogram, first extracted vessels are subtracted from original image, and after removing detected background by morphological operators and enhancing bright small pixels, micro-aneurisms are detected. 70 patients were involved in this study to classify diabetic retinopathy into 3 groups, that is, (1) no diabetic retinopathy, (2) mild/moderate nonproliferative diabetic retinopathy, (3) severe nonproliferative/proliferative diabetic retinopathy, and our simulations show that the proposed system has sensitivity and specificity of 100% for grading.

Optical coherence tomography angiography in diabetic patients without diabetic retinopathy

2019 ◽  
Vol 30 (6) ◽  
pp. 1418-1423 ◽  
Author(s):  
Claudio Furino ◽  
Grazia Montrone ◽  
Maria Vittoria Cicinelli ◽  
Stefania Balestra ◽  
Maria Oliva Grassi ◽  
...  
Keyword(s):  
Optical Coherence Tomography ◽  
Diabetic Retinopathy ◽  
Optical Coherence Tomography Angiography ◽  
Vessel Density ◽  
Foveal Avascular Zone ◽  
Diabetic Patients ◽  
Optical Coherence ◽  
Avascular Zone ◽  
Capillary Plexus ◽  
Superficial Capillary Plexus

Purpose: To investigate a subset of diabetic patients without diabetic retinopathy with optical coherence tomography angiography, assessing the differences in macular perfusion between diseased eyes and healthy controls. Methods: Monocentric cross-sectional study, including 86 eyes from 43 diabetic patients with no clinical signs of diabetic retinopathy and 78 eyes from 39 controls. Patients underwent 3.0 × 3.0 mm and 4.5 × 4.5 mm swept-source optical coherence tomography angiography. Vessel density (%), foveal avascular zone area (mm2), and avascular density (%) were provided for the superficial capillary plexus and the deep capillary plexus. Results: The foveal avascular zone area at the superficial capillary plexus was larger in the study group compared to controls, irrespective of the area of the slab considered. A meaningful difference was found in the vessel density at the deep capillary plexus of the 3.0 × 3.0 mm slab (p = 0.03). Almost all the variables considered in the study showed a significant within-subject effect. Age significantly correlated with vessel density of superficial capillary plexus on 4.5 × 4.5 mm in both control and diabetic eyes. Conclusion: Diabetic patients with subclinical diabetic retinopathy feature a larger foveal avascular zone at the superficial capillary plexus compared with controls, as well as relative reduction of the vessel density at the deep capillary plexus. These findings might serve as the basis for screening between normal and diabetic subjects.

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