Non-invasive multimodal imaging of Diabetic Retinopathy: A survey on treatment methods and Nanotheranostics

: Diabetic retinopathy is posterior eye disorder in which a damage occurs to the light sensitive retina due to diabetes mellitus, and affects people aged 18 - 64 with type ІІ diabetes. This disease progresses through different pathophysiological pathways. This includes oxidative stress, inflammation, stimulation of the growth factor in the eye’s vasculature, isoforms of protein kinase C, and also the activation of the hexosamine pathway. It starts as micro aneurysms and advances in complicated stage which results in retinal detachment. Treatment of posterior eye diseases has complications which are due to the structural design of the eye and physiological barriers present. The current treatment approach involves use of intravitreal anti-VEGFs, corticosteroids implants, laser and surgery; these treatment methods have drawbacks attributed to them despite their benefits. Development of a robust delivery system with minimal or no invasion to tackle the issues of diabetic retinopathy will be of considerable benefit to patients having diabetic retinopathy; the dependency on ophthalmologists for multiple injections will significantly reduce and provide a promising approach in drug delivery. In this review article, the authors provided information related to existing treatment methods available for diabetic retinopathy, the most significant nanotechnology approach through which local delivery via the ocular route to posterior eye can be achieved. It also possesses the various carriers studied for the non-invasive approach for retinal delivery of medicaments. Non-invasive approach for delivery of drugs can be considered as potential for treatment of diabetic retinopathy.

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Review of Various Tasks Performed in the Preprocessing Phase of a Diabetic Retinopathy Diagnosis System

Current Medical Imaging Formerly Current Medical Imaging Reviews ◽

10.2174/1573405615666190219102427 ◽

2020 ◽

Vol 16 (4) ◽

pp. 397-426

Author(s):

Muhammad Nadeem Ashraf ◽

Muhammad Hussain ◽

Zulfiqar Habib

Keyword(s):

Diabetic Retinopathy ◽

Blood Vessels ◽

Early Stage ◽

Spherical Shape ◽

Cost Effective ◽

Lesion Detection ◽

Diabetic Patients ◽

Cad System ◽

Non Invasive ◽

Optic Discs

Diabetic Retinopathy (DR) is a major cause of blindness in diabetic patients. The increasing population of diabetic patients and difficulty to diagnose it at an early stage are limiting the screening capabilities of manual diagnosis by ophthalmologists. Color fundus images are widely used to detect DR lesions due to their comfortable, cost-effective and non-invasive acquisition procedure. Computer Aided Diagnosis (CAD) of DR based on these images can assist ophthalmologists and help in saving many sight years of diabetic patients. In a CAD system, preprocessing is a crucial phase, which significantly affects its performance. Commonly used preprocessing operations are the enhancement of poor contrast, balancing the illumination imbalance due to the spherical shape of a retina, noise reduction, image resizing to support multi-resolution, color normalization, extraction of a field of view (FOV), etc. Also, the presence of blood vessels and optic discs makes the lesion detection more challenging because these two artifacts exhibit specific attributes, which are similar to those of DR lesions. Preprocessing operations can be broadly divided into three categories: 1) fixing the native defects, 2) segmentation of blood vessels, and 3) localization and segmentation of optic discs. This paper presents a review of the state-of-the-art preprocessing techniques related to three categories of operations, highlighting their significant aspects and limitations. The survey is concluded with the most effective preprocessing methods, which have been shown to improve the accuracy and efficiency of the CAD systems.

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Left ventricular pseudoaneurysm: an inadvertent consequence of COVID-19—a case report

European Heart Journal - Case Reports ◽

10.1093/ehjcr/ytab203 ◽

2021 ◽

Vol 5 (7) ◽

Author(s):

Stephen Brennan ◽

Saadah Sulong ◽

Matthew Barrett

Keyword(s):

Multimodal Imaging ◽

Coronary Artery Occlusion ◽

Artery Occlusion ◽

Left Ventricular ◽

Medical Complications ◽

Mechanical Complication ◽

Resonance Imaging ◽

Left Ventricular Pseudoaneurysm ◽

Non Invasive ◽

Case Summary

Abstract Background Left ventricular pseudoaneurysm (LVP) is an uncommon but serious mechanical complication of acute myocardial infarction (AMI). The immediate medical complications of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) are well recognized, but its indirect effect on patients and healthcare systems is potentially less perceivable. Case summary In this report, a 72-year-old man who was anxious about attending hospital during the SARS-CoV-2 pandemic was eventually found to have a total right coronary artery occlusion after a delayed emergency department presentation. He ultimately developed severe symptomatic heart failure and cardiac magnetic resonance imaging (CMR) revealed that a large LVP with concomitant severe ischaemic mitral regurgitation had evolved from his infarct. The patient was successfully discharged home after the surgical replacement of his mitral valve and repair of his LVP. Discussion This case highlights a salient downstream effect of Coronavirus disease 2019 (COVID-19): the delay in presentation, diagnosis, and management of common treatable conditions such as AMI. It also underscores the importance of non-invasive multimodal imaging on the timely identification of the mechanical complications of AMI. In particular, CMR can play a crucial role in the characterization and management of LVP.

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An Instrument for Accurate and Non-Invasive Screening of Skin Cancer Based on Multimodal Imaging

IEEE Access ◽

10.1109/access.2019.2956898 ◽

2019 ◽

Vol 7 ◽

pp. 176646-176657 ◽

Cited By ~ 2

Author(s):

Silvana Diaz ◽

Thomas Krohmer ◽

Alvaro Moreira ◽

Sebastian E. Godoy ◽

Miguel Figueroa

Keyword(s):

Skin Cancer ◽

Multimodal Imaging ◽

Non Invasive

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Optical coherence tomography angiography of foveal neovascularisation in proliferative diabetic retinopathy

BMJ Case Reports ◽

10.1136/bcr-2019-230382 ◽

2019 ◽

Vol 12 (8) ◽

pp. e230382

Author(s):

Deven Dhurandhar ◽

Padmaja Kumari Rani

Keyword(s):

Optical Coherence Tomography ◽

Diabetic Retinopathy ◽

Proliferative Diabetic Retinopathy ◽

Optical Coherence Tomography Angiography ◽

Imaging Modality ◽

Diabetic Macular Oedema ◽

Hypertensive Retinopathy ◽

Optical Coherence ◽

Non Invasive

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.

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Multimodal Imaging of Diabetic Retinopathy in a Patient With Fovea Plana

Retina ◽

10.1097/iae.0000000000001020 ◽

2016 ◽

Vol 36 (10) ◽

pp. e93-e94 ◽

Cited By ~ 2

Author(s):

Giuseppe Querques ◽

Luisa Pierro ◽

Ilaria Zucchiatti ◽

Eleonora Corbelli ◽

Lea Querques ◽

...

Keyword(s):

Diabetic Retinopathy ◽

Multimodal Imaging

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627. Non-Invasive, Multimodal Imaging of Microvesicles with Metabolically Biotinylated, Membrane-Bound Gaussia Luciferase

Molecular Therapy ◽

10.1016/s1525-0016(16)36431-0 ◽

2012 ◽

Vol 20 ◽

pp. S241

Keyword(s):

Multimodal Imaging ◽

Gaussia Luciferase ◽

Non Invasive ◽

Membrane Bound

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Computer-aided Analysis of Fundus Photographs

European Ophthalmic Review ◽

10.17925/eor.2011.05.02.104 ◽

2011 ◽

Vol 05 (02) ◽

pp. 104

Author(s):

Luisa Ribeiro ◽

Rui Bernardes ◽

José Cunha-Vaz ◽

◽

...

Keyword(s):

Diabetic Retinopathy ◽

Imaging Modality ◽

Retinal Disease ◽

Automated Analysis ◽

Fundus Photography ◽

Individual Risk ◽

Invasive Procedures ◽

Non Invasive ◽

Computer Aided Analysis ◽

Computer Aided

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.

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Peripheral capillary non-perfusion in treatment-naïve proliferative diabetic retinopathy associates with postoperative disease activity 6 months after panretinal photocoagulation

British Journal of Ophthalmology ◽

10.1136/bjophthalmol-2018-312195 ◽

2018 ◽

Vol 103 (6) ◽

pp. 816-820 ◽

Cited By ~ 6

Author(s):

Thomas Lee Torp ◽

Ryo Kawasaki ◽

Tien Yin Wong ◽

Tunde Peto ◽

Jakob Grauslund

Keyword(s):

Diabetic Retinopathy ◽

Disease Activity ◽

Proliferative Diabetic Retinopathy ◽

Laser System ◽

Predictive Marker ◽

Panretinal Photocoagulation ◽

Non Invasive ◽

Navigated Laser ◽

Treatment Naïve ◽

And Function

Background/aimsWith the perspective to provide individualised panretinal laser photocoagulation (PRP) for proliferative diabetic retinopathy (PDR), we evaluated if retinal peripheral capillary non-perfusion (PCNP) and oximetry, as non-invasive markers of retinal metabolism and function, could predict disease activity 6 months after PRP.MethodsWe performed a prospective, interventional study of patients with treatment-naïve PDR. Retinal oximetry and ultra-widefield fluorescein angiography were performed at baseline (BL) and three (3M) and 6 months (6M) after PRP by a navigated laser system. At 6M follow-up, patients were divided according to disease activity: active or inactive.ResultsWe included 33 eyes, and 69.6% were men. At BL, the median age and duration of diabetes (with IQRs) were 51.6±23.4 and 20.0±15.0 years. Haemoglobin A1c was 63.0±17.0 mmol/mol and blood pressure was 152±37/82±24 mm Hg. At BL and M6, patients with postoperative disease activity (30.3.%, n=10) had a larger area with PCNP than those with inactive PDR (BL: 51%–75% vs 26%–50%, p=0.03; 6M: 51%–75% vs 26%–50%, p=0.03). The area of PCNP did not change from BL to 6M in either group (inactive PDR: p=0.38, active PDR: p=0.87). Changes in retinal oxygen saturation were not found to be clinical relevant.ConclusionWe found the area of PCNP at all timepoints to be statistically larger in patients with active PDR 6 months after PRP treatment. Therefore, the area of PCNP, at baseline, may serve as a potential predictive marker for PDR activity after treatment.

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Optical Coherence Tomography Angiography of Foveal Neovascularization in Diabetic Retinopathy

Case Reports in Ophthalmology ◽

10.1159/000485831 ◽

2018 ◽

Vol 9 (1) ◽

pp. 93-97 ◽

Cited By ~ 3

Author(s):

Konstantinos Andreanos ◽

Tryfon Rotsos ◽

George Kymionis ◽

Chryssanthi Koutsandrea ◽

Athanasios Kotsolis ◽

...

Keyword(s):

Optical Coherence Tomography ◽

Diabetic Retinopathy ◽

Proliferative Diabetic Retinopathy ◽

Multimodal Imaging ◽

Optical Coherence Tomography Angiography ◽

Insulin Dependent Diabetes Mellitus ◽

Dependent Diabetes Mellitus ◽

Optical Coherence ◽

Diagnostic Investigation ◽

Insulin Dependent

Purpose: To report a case of foveal neovascularization in a patient with proliferative diabetic retinopathy as seen on optical coherence tomography angiography (OCT-A). Methods: Multimodal imaging was used for diagnostic investigation. Patient: A 61-year-old male with a 16-year history of insulin-dependent diabetes mellitus was referred to our medical retina department for examination and management. Meticulous fundus examination and multimodal imaging revealed proliferative diabetic retinopathy lesions, including neovascularization located in the foveal area. Results: OCT-A allowed us to detect the neovascular lesion, confirm that it originated from perifoveal capillaries, estimate its retinal depth, and evaluate the vessel blood flow in multiple layers. Conclusion: To the best of our knowledge this is the first report of OCT-A imaging of foveal neovascularization in diabetic retinopathy. OCT-A is a very useful examination for the diagnostic investigation of patients with diabetic retinopathy.

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