Treatment of neovascular age-related macular degeneration in patients with diabetes

The number of patients with type 2 diabetes continues to rise; an anticipated 300 million people will be affected by 2025. The immense social and economic burden of the condition is exacerbated by the initial asymptomatic nature of type 2 diabetes, resulting in a high prevalence of micro-and macrovascular complications at presentation. Diabetic retinopathy, one of the potential microvascular complications associated with diabetes, and neovascular age-related macular degeneration (AMD) are the two most frequent retinal degenerative diseases, and are responsible for the majority of blindness due to retinal disease. Both conditions predominantly affect the central macula, and are associated with the presence of retinal edema and an aggressive inflammatory repair process that accelerates disease progression. The associated retinal edema and the inflammatory repair process are directly involved in the breakdown of the blood-retinal barrier (BRB). Yet, the underlying alterations to the BRB caused by the diseases are very different. The coexistence of the two conditions appears to be relatively uncommon, suggesting that diabetes may even protect patients from developing neovascular AMD. However, it is thought that the inflammatory repair responses associated with diabetic retinopathy and neovascular AMD may be cumulative and, in patients affected by both, could result in chronic diffuse cystoid edema. Treatment considerations in such patients should, therefore, include the role of retinal edema and the increased susceptibility of patients with diabetes to potential systemic side effects associated with agents administered repeatedly for neovascular AMD treatment

Insulator materials for electrical passivation of thin film solar cells

Currently, renewable energies are being developed in order to replace the fossil fuels. In the re-newable energies field, photovoltaics plays a vital role. Thin film technology has the potential to be an important player in the renewable energy market since it can, still decrease significantly its production costs with high material savings while keeping very high values of electrical performance. One of the thin film technologies is the Cu(In,Ga)Se2 (CIGS). This technology, with long term stability, high values of light to power conversion efficiency is already present in the market but many developments are still needed. One of them deals with the recombination losses happening in the CIGS interfaces which contribute to a decrease in its electrical performance. In order to prevent these losses, passivation layers placed in the interfaces of the CIGS can vastly decrease the recombination losses. In this work, the aim is to study of the effects of different passivation materials on CIGS technol-ogy jointly with the best deposition conditions. Thus, several techniques like Raman spectroscopy, X-ray diffraction and photoluminescence, were used in order to study the CIGS surface damage due to the insulator deposition. Finally, MIS structures were fabricated to study the CIGS-insulator interface elec-trical properties

Synthtic OCT Data for image processing performance testing

The use of synthetic images is needed for testing the performance of image processing methods in order to establish a ground truth to test performance metrics. However, these synthetic images do not represent real applications. The aim of this paper is to build a mathematical model to obtain a synthetic noise-free image mimicking a real Optical Coherence Tomography (OCT) B-scan or volume from the human retina, in order to establish a ground truth for filtering performance metrics in this context. Moreover we also suggest a method to add speckle noise to this image based on the speckle noise of the given OCT volume. In this way we establish a replicable method to obtain a ground truth for image processing performance metrics that actually mimics a real case.FCTFEDERProgram COMPET

Optical coherence tomography: automatic retina classification through support vector machines

Optical coherence tomography (OCT) is becoming one of the most important imaging modalities in ophthalmology due to its non-invasiveness and by allowing the visualisation the human retina structure in detail. It was recently proposed that OCT data embeds functional information from the human retina. Specifically, it was proposed that blood–retinal barrier status information is present within OCT data from the human retina. Besides this ability, the authors present data supporting the idea of having the OCT data encoding the ageing of the retina in addition to the disease (diabetes) condition from the healthy status. The methodology followed makes use of a supervised classification procedure, the support vector machine (SVM) classifier – based solely on the statistics of the distribution of OCT data from the human retina (i.e. OCT data between the inner limiting membrane and the retinal pigment epithelium). Results achieved suggest that information on both the healthy status of the blood–retinal barrier and on the ageing process co-exist encoded within the optical properties of the human retina

Improved adaptive complex diffusion despeckling filter

Despeckling optical coherence tomograms from the human retina is a fundamental step to a better diagnosis or as a preprocessing stage for retinal layer segmentation. Both of these applications are particularly important in monitoring the progression of retinal disorders. In this study we propose a new formulation for a well-known nonlinear complex diffusion filter. A regularization factor is now made to be dependent on data, and the process itself is now an adaptive one. Experimental results making use of synthetic data show the good performance of the proposed formulation by achieving better quantitative results and increasing computation speed.Fundação para a Ciência e TecnologiaFEDERPrograma COMPET

Objective Assessment of Sleep Movements in Neurodegenerative Patients Trough an Electrotextile Tool

The present research work aims at the integration of textile materials and electronic components for the development of a new electrotextile structure to be used in human medicine and healthcare, specifically, in monitoring sleep movements of patients with neurodegenerative disease such as Alzheimer and Parkinson’s. In this context, we sought the development of a new technological solution that allows not only to assess sleep quality, but also to establish a link between the nocturnal movements (body area, number of movements, direction, intensity) of demented patients and their polysomnographic recorded data. For this purpose, the authors developed an electroactive textile system, in order to acquire biomechanic information during the patients’ night rest. The collected data will be statistically processed to verify any relation between night movements and the stage of the disease. Keywords: Smart textiles, Sleep assessment, Polysomnography, Electrotextiles, Neurodegenerative disease

Characterization of initial stages of diabetic macular edema

This study is aimed at characterizing the type of retinal edema in the initial stages of retinopathy in type 2 diabetes. In this retrospective cross-sectional study, spectral domain optical coherence tomography (OCT) layer by layer analysis of the retina in association with OCT-Leakage, an algorithm to detect sites of low optical reflectivity, were used to examine eyes with minimal, mild, and moderate diabetic retinopathy (DR). A total of 142 eyes from 142 patients (28% women) aged 52–88 years were imaged. Macular edema, either subclinical (SCME) or central-involved macular edema (CIME), was present in 43% of eyes in group 10–20, 41% of eyes in group 35, and 38% of eyes in group 43–47. The inner nuclear layer (INL) was the layer showing higher and most frequent increases in retinal thickness (79%). The edema was predominantly intracellular in group 10–20 (65%) and extracellular in groups 35 (77%) and 43–47 (69%). Eyes from diabetic patients in the initial stages of DR with different Early Treatment Diabetic Retinopathy Study gradings show similar prevalence of SCME and CIME, independent of the severity of the retinopathy. Retinal edema is located mainly in the INL and appears to be mostly extracellular except in the earliest stages of diabetic retinal disease where intracellular edema predominates.info:eu-repo/semantics/publishedVersio

Ocular fundus Imaging: from structure to function

Imaging the ocular fundus, namely the retina, to detect and/or monitor changes over time from the healthy condition is of fundamental importance to assess onset and disease progression and is a valuable tool to understand the basic mechanisms of ocular diseases. Current trends point to the need for less or non-invasive approaches, to the need for detailed (higher spatial and temporal resolution) imaging systems and to the quantification as opposed to qualitative classification of any findings. In this work we present a snapshot of our research by presenting two examples of technical development aiming to obtain structural and function information from the human retina, in vivo, using non-invasive techniques, namely optical coherence tomography imaging. Based on our experience and developed work, we are now starting to bridge the gap to brain imaging as the eye is only the starting point of vision.FCTFEDERProgram COMPET

Progression of Ganglion Cell-Inner Plexiform layer thickness in the initial stages of diabetic retinopathy in type 2 diabetic patients: a 5-year longitudinal study

Diabetic Retinopathy (DR)is a frequent complication of DiabetesMellitus (DM) andthe main cause of vision loss in the working population in western countries. Diabetic Retinopathy has always been considered a microvascular disease, but it has been suggested that neurodegeneration is also associated with this complex pathology[1], although there is evidence indicating that the neurodegenerative process may progress independently[2]. To evaluate this potential association, we have examined the progression of neurodegeneration over a 5-year period of follow-up (considering thinning of ganglion cell + inner plexiform retinal layers (GCL+IPL) in individuals with type 2 diabetes (T2D) and nonproliferative DR) and explored whetheritis associated with microaneurysmturnover (MAT), diseaselevel at baseline and severity progression.info:eu-repo/semantics/publishedVersio