Computer-aided Analysis of Fundus Photographs

2011 ◽  
Vol 05 (02) ◽  
pp. 104
Author(s):  
Luisa Ribeiro ◽  
Rui Bernardes ◽  
José Cunha-Vaz ◽  
◽  
◽  
...  

Colour fundus photography is the most frequently used imaging modality because it is non-invasive, well accepted by patients and above all, because it allows documentation and automated analysis of the ophthalmoscopic examination. Colour fundus photography is considered crucial for diabetic retinopathy management to identify disease and its progression in clinical practice. This article focuses on automated computer-aided analysis of fundus digital photographs with special emphasis on microaneurysm dynamics. Together with optical coherence tomography measurements of extracellular space and retinal thickness, both based on non-invasive procedures, this technique allows close follow-up of the main changes in the diabetic retina. Determination of the activity of the retinal disease and individual risk profiles using these non-invasive procedures contribute to personalised management of diabetic retinopathy by identifying eyes at risk from vision-threatening complications, such as macular oedema and proliferative retinopathy.

2019 ◽  
Vol 12 (8) ◽  
pp. e230382
Author(s):  
Deven Dhurandhar ◽  
Padmaja Kumari Rani

A 52-year-old man, a known case of type 2 diabetes mellitus and hypertension, who presented to us with bilateral diminution of vision since 1 year. He was diagnosed as a case of bilateral proliferative diabetic retinopathy and hypertensive retinopathy. A non-invasive imaging modality, optical coherence tomography angiography (OCTA), detected foveal neovascularisation in a background of diffuse diabetic macular oedema which would have been obscured by other investigations like fluorescein angiography.


2020 ◽  
Vol 12 ◽  
pp. 251584142095051 ◽  
Author(s):  
Ashish Markan ◽  
Aniruddha Agarwal ◽  
Atul Arora ◽  
Krinjeela Bazgain ◽  
Vipin Rana ◽  
...  

Diabetic retinopathy is one of the major microvascular complications of diabetes mellitus. The most common causes of vision loss in diabetic retinopathy are diabetic macular edema and proliferative diabetic retinopathy. Recent developments in ocular imaging have played a significant role in early diagnosis and management of these complications. Color fundus photography is an imaging modality, which is helpful for screening patients with diabetic eye disease and monitoring its progression as well as response to treatment. Fundus fluorescein angiography (FFA) is a dye-based invasive test to detect subtle neovascularization, look for areas of capillary non-perfusion, diagnose macular ischemia, and differentiate between focal and diffuse capillary bed leak in cases of macular edema. Recent advances in retinal imaging like the introduction of spectral-domain and swept source-based optical coherence tomography (OCT), fundus autofluorescence (FAF), OCT angiography, and ultrawide field imaging and FFA have helped clinicians in the detection of certain biomarkers that can identify disease at an early stage and predict response to treatment in diabetic macular edema. This article will summarize the role of different imaging biomarkers in characterizing diabetic retinopathy and their potential contribution in its management.


2019 ◽  
Vol 6 (1) ◽  
Author(s):  
Kai Yuan Tey ◽  
Kelvin Teo ◽  
Anna C. S. Tan ◽  
Kavya Devarajan ◽  
Bingyao Tan ◽  
...  

Abstract Background Diabetic retinopathy (DR) is a leading cause of vision loss in adults. Currently, the standard imaging technique to monitor and prognosticate DR and diabetic maculopathy is dye-based angiography. With the introduction of optical coherence tomography angiography (OCTA), it may serve as a potential rapid, non-invasive imaging modality as an adjunct. Main text Recent studies on the role of OCTA in DR include the use of vascular parameters e.g., vessel density, intercapillary spacing, vessel diameter index, length of vessels based on skeletonised OCTA, the total length of vessels, vascular architecture and area of the foveal avascular zone. These quantitative measures may be able to detect changes with the severity and progress of DR for clinical research. OCTA may also serve as a non-invasive imaging method to detect diabetic macula ischemia, which may help predict visual prognosis. However, there are many limitations of OCTA in DR, such as difficulty in segmentation between superficial and deep capillary plexus; and its use in diabetic macula edema where the presence of cystic spaces may affect image results. Future applications of OCTA in the anterior segment include detection of anterior segment ischemia and iris neovascularisation associated with proliferative DR and risk of neovascular glaucoma. Conclusion OCTA may potentially serve as a useful non-invasive imaging tool in the diagnosis and monitoring of diabetic retinopathy and maculopathy in the future. Future studies may demonstrate how quantitative OCTA measures may have a role in detecting early retinal changes in patients with diabetes.


2018 ◽  
Vol 1 (1) ◽  
pp. 1
Author(s):  
Prettyla Yollamanda ◽  
Arief Kartasasmita ◽  
Iwan Sovani ◽  
Erwin Iskandar ◽  
Rova Virgana ◽  
...  

Introduction: Diabetic Retinopathy (DR) is a common microvascular complication in patients with Diabetes Mellitus (DM) that can cause visual impairment and blindness in adult populations. Retinal microvascular changes, reflecting capillary drop out, non perfusion, and retinal ischemia seen in patients with DM can be assessed not only qualitatively, but also quantitatively with the introduction of a new, non invasive imaging modality Optical Coherence Tomography Angiography (OCTA), avoiding potential advese risks that can occur with the use of dye-injection imaging technique. We quantified retinal microvascular changes in healthy control eyes and Diabetic Retinopathy using OCTA. Methods: A cross sectional study included 13 eyes of 9 patients with DR, consists of 11 eyes with Non Proliferative Diabetic Retinopathy (NPDR) and 2 eyes with Proliferative Diabetic Retinopathy (PDR) and 5 eyes of 5 age-matched controls. Participants were imaged with commercial OCTA device (CIRRUS HD-OCT 5000 Angioplex). We analyzed in the Superficial Capillary Plexus (SCP) the following OCTA parameters : Vessel Density (VD), Foveal Avascular Zone (FAZ) area, and FAZ circularity. Result: Normal eyes had a higher mean VD, FAZ circularity (p >0.05) and lower mean FAZ area ( p <0.05) in the SCP compared with the DR (NPDR + PDR) group. If we excluded the PDR eyes from the analytic data, mean VD and FAZ area were found to be lower in control group, and mean FAZ circularity was higher. However, no quantitative parameters were statistically significant between control group and NPDR group. Conclusion: Microvascular changes in DR can be assessed with the use of Optical Coherence Tomography Angioraphy, which is non invasive and provides high quality of images acquired from the chosen level of retina.


2021 ◽  
Vol 1 (3) ◽  
pp. 332-352
Author(s):  
Ellie Bowditch ◽  
Andrew Chang ◽  
Hemal Mehta

Diagnosis and management of proliferative diabetic retinopathy are reliant upon retinal imaging. A systematic literature review of non-invasive imaging to guide diagnosis and treatment of proliferative diabetic retinopathy was performed. There is a trend of moving away from invasive (e.g., fundus fluorescein angiography) to non-invasive (e.g., wide-field optical coherence tomography (OCT), OCT angiography and colour fundus photography) imaging modalities to allow for more objective assessments that can be readily repeated in a time-efficient manner without compromising patient safety. Such quantitative assessments generating large amounts of data could benefit from artificial intelligence approaches to aid clinical decision making. These non-invasive imaging modalities continue to improve both in terms of the quality of image acquisition and progress in image interpretation. It is important that newer non-invasive imaging modalities are appropriately validated in large-scale prospective observational studies or randomised clinical trials.


Author(s):  
Prasanna Porwal ◽  
Samiksha Pachade ◽  
Manesh Kokare ◽  
Girish Deshmukh ◽  
Vivek Sahasrabuddhe

Diabetic Retinopathy, a condition in the person affected by diabetes, is most common cause of blindness in the world. Recent research has given a better understanding of requirement in clinical eye care practice to identify better and cheaper ways of identification, management, diagnosis and treatment of retinal disease. The importance of diabetic retinopathy screening programs and difficulty in achieving reliable early diagnosis of diabetic retinopathy at a reasonable cost needs attention to develop computer-aided diagnosis tool. Computer aided disease diagnosis in retinal image analysis could ease mass screening of population with diabetes mellitus and help clinicians in utilizing their time more efficiently. The recent technological advances in computing power, communication systems, and machine learning techniques provide opportunities to the biomedical engineers and computer scientists to meet the requirements of clinical practice. With proper self-care, management, and medical professional support, individuals with diabetes can live a healthy and long life.


Author(s):  
Niraj Doshi ◽  
Gerald Schaefer

Nailfold capillaroscopy (NC) is a non-invasive imaging technique employed to assess the condition of blood capillaries in the nailfold, and is routinely used for the detection of scleroderma spectral disorders, Raynaud's phenomenon and other connective tissue diseases. In this chapter, we present computer-aided approaches for capillary inspection, in particular focussing on the tasks of image enhancement, binarisation and skeletonisation. We evaluate the performance of a number image enhancement/noise removal techniques for NC images, as a pre-cursor to edge detection aimed at identifying capillaries. Results show that bilateral filters and enhancers provide the best overall image quality. Following noise removal, NC images typically get converted into binary form. For this purpose, we employed a difference-of-Gaussian approach before thresholding. The final stage is that of skeletonisation, which can be effectively performed using a rule-based thinning algorithm. Thus the complete imaging pipeling of pre-processing, binarisation and skeletonisation is represented in this chapter.


2021 ◽  
Vol 1 (3) ◽  
pp. 286-305
Author(s):  
John Moir ◽  
Saira Khanna ◽  
Dimitra Skondra

Diabetes mellitus (DM), a disorder rapidly growing in prevalence, is linked to the retinal microvasculature complication diabetic retinopathy (DR). As one of the leading global causes of vision impairment and loss, imaging techniques to detect and monitor DR must continue to improve in order to address this growing burden. Optical coherence tomography angiography (OCTA) is a nascent imaging modality that generates three-dimensional visualizations of the retinal and choroidal microvasculature. Compared to fluorescein angiography, the gold-standard imaging modality for retinal vessels, OCTA offers the advantages of being non-invasive, quick, and able to resolve the multiple plexuses within the retina. Quantitative OCTA studies have explored parameters such as vessel density (VD), foveal avascular zone (FAZ), acircularity index, vessel tortuosity (VT), and fractal dimension (FD) amongst DR patients. This review synthesizes the main trends emerging from quantitative OCTA-based studies of DR and interrogates them within the context of DR pathophysiology. We offer a glimpse into how analysis techniques have shifted in the years since OCTA came into existence, while speculating on its future role in clinical practice.


Sign in / Sign up

Export Citation Format

Share Document