This work deals with mathematical description of nerve fiber bundle trajectories for the diagnosis of glaucoma. Also gives a brief explanation in the principle of fundus camera and glaucoma. Its aim is to implement the model into MATLAB software, to project a~methodics of its use and also to realize it.

This master’s thesis gives a description of fundus camera as a medical imaging system. Sub features of this system are explained in short, thus examples of certain construction variants are given. Furthermore, the work deals with image fusion and associated possibilities of digital image processing. One set of consecutive scanned images of human eye’s retina has been provided for the practical part of this work. During program processing of these data, decomposition of obtained images to single-color sequences is performed. For these partial monochromatic sequences, monomodal registration is performed, based on calculation of the brightness similarity criterion between the pairs of images. From the three created monochromatic sequences of registered images, new sequence of color images is created, using multimodal registration of each image triples. As a basis for similarity evaluation during multimodal registration, an information similarity criterion was used.

This thesis deals with recognition by retina (identification, verification). In introduction we describe information about human eye, its diseases with focus on retina impact. Further (in main part) we conduct SW analyses based on biometry retina requirements and design of SW application for retina recognition. It is based on processing pipeline design (sequential application of image filters). This pipeline mostly contains filters focused on edge detection, adaptive threshold and skeletonisation. Finally, basic SW functions includes users registration (enroll), identification, verification. In conclusion we discuss experimental results and success of designed SW in practical application.

Η λαπαροσκοπική γαστρική παράκαμψη κατά Roux-en-Y είναι μία από τις πιο ευρέως χρησιμοποιούμενες βαριατρικές επεμβάσεις για την αντιμετώπιση της νοσογόνου παχυσαρκίας. Η απώλεια βάρους μετά από βαριατρικού τύπου επεμβάσεις έχει συσχετισθεί με τις επερχόμενες μεταβολές των γαστρεντερικών ορμονών, που έχει δειχθεί ότι συνδέονται με τον έλεγχο του μεταβολισμού και της όρεξης. Σκοπός: Η μελέτη της επίδρασης της εκτομής του θόλου του στομάχου σε ασθενείς με νοσογόνο παχυσαρκία που υποβάλλονται σε λαπαροσκοπική γαστρική παράκαμψη στην έκκριση των ορμονών, τα επίπεδα της γλυκόζης αλλά και την απώλεια βάρους. Μέθοδος: Δώδεκα ασθενείς υποβλήθηκαν σε λαπαροσκοπική γαστρική παράκαμψη και δώδεκα σε λαπαροσκοπική γαστρική παράκαμψη και εκτομή του θόλου του στομάχου. Όλοι οι ασθενείς μελετήθηκαν προοπτικά πρίν και τρείς, έξι και δώδεκα μήνες μετά την επέμβαση. Η συλλογή των δειγμάτων έγινε μετά από δωδεκάωρη νηστεία και 30, 60 και 120 λεπτά μετά την χορήγηση πρότυπου γεύματος θερμιδικού φορτίου 300 Kcal. Αποτελέσματα: Το σωματικό βάρος και ο δείκτης μάζας σώματος μειώθηκαν σημαντικά (p<0.001) και στις δύο ομάδες χωρίς όμως διαφορές μεταξύ των ομάδων. Για την ομάδα της γαστρικής παράκαμψης τα επίπεδα γκρελίνης νηστείας μειώθηκαν στους τρείς μήνες μετεγχειρητικά και αυξήθηκαν στούς δώδεκα μήνες σε επίπεδα υψηλότερα σε σχέση με τα προεγχειρητικά (p<0.01), αντίθετα, μετά από λαπαροσκοπική γαστρική παράκαμψη και εκτομή του θόλου, τα επίπεδα γκρελίνης νηστείας μειώθηκαν σημαντικά και παρέμειναν χαμηλά σε όλες τις χρονικές στιγμές της μελέτης (p<0.01). H μεταγευματική απόκριση του PYY, του GLP-1 και της ινσουλίνης ενισχύθηκαν μετεγχειρητικά (p<0.01) και στις δύο επεμβάσεις αλλά η απόκριση ήταν σημαντικά μεγαλύτερη και τα μεταγευματικά σάκχαρα χαμηλότερα μετά από γαστρική παράκαμψη και εκτομή του θόλου του στομάχου (p for interaction <0.05). Μετεγχειρητικά οι μεταβολές της γκρελίνης συσχετίστηκαν αρνητικά με τις μεταβολές του GLP-1. Συμπεράσματα: Η εκτομή του θόλου του στομάχου σε ασθενείς που υποβάλλονται σε λαπαροσκοπική γαστρική παράκαμψη οδηγεί σε χαμηλότερα βασικά επίπεδα γκρελίνης, σε μεγαλύτερη μεταγευματική απόκριση GLP-1, PYY και ινσουλίνης και σε χαμηλότερα σάκχαρα σε σχέση με την λαπαροσκοπική γαστρική παράκαμψη. Η εκτομή του θόλου του στομάχου με συνοδό γαστρική παράκαψη μπορεί να αποδειχθεί μια πολύ χρήσιμη καινούργια χειρουργική τεχνική για την αντιμετώπιση της νοσογόνου παχυσαρκίας και του σακχαρώδη διαβήτη τύπου ΙΙ. / Background: Laparoscopic Roux-en Y-Gastric bypass (LRYGBP) is the commonest available option for the surgical treatment of morbid obesity. Weight loss following bariatric surgery has been linked to changes of gastrointestinal peptides, shown to be implicated also in metabolic effects and appetite control. The purpose of this study was to evaluate whether gastric fundus resection in patients undergoing LRYGBP enhances the efficacy of the procedure in terms of weight loss, glucose levels and hormonal secretion. Methods: 12 patients underwent LRYGBP and 12 patients LRYGBP plus gastric fundus resection (LRYGBP+FR). All patients were evaluated before and at 3, 6, and 12 months postoperatively. Blood samples were collected after an overnight fast and 30, 60 and 120 min after a standard 300 kcal mixed meal. Results: Body weight and body mass index decreased markedly and comparably after both procedures. Fasting ghrelin decreased three months after LRYGBP, but increased at 12 months to levels higher than baseline while after LRYGBP+FR was markedly and persistently decreased. Postprandial GLP-1, PYY and insulin responses were enhanced more and postprandial glucose levels were lower after LRYGBP+FR compared to LRYGBP. Postoperatively, ghrelin changes correlated negatively with GLP-1 changes. Conclusions: Resection of the gastric fundus in patients undergoing LRYGBP was associated with persistently lower fasting ghrelin levels, higher postprandial PYY, GLP-1 and insulin responses and lower postprandial glucose levels compared to LRYGBP. These findings suggest that fundus resection in the setting of LRYGBP may be more effective than RYGBP for the management of morbid obesity and diabetes type 2.

Research into automatic retina image analysis has become increasingly important, not just in ophthalmology but also in other clinical specialities such as cardiology and neurology. In the retina, blood vessels can be directly visualised non-invasively in-vivo, and hence it serves as a "window" to cardiovascular and neurovascular complications. Biomarker research, i.e. investigating associations between the morphology of the retinal vasculature (as a means of revealing microvascular health or disease) and particular conditions affecting the body or brain could play an important role in detecting disease early enough to impact on patient treatment and care. A fundamental requirement of biomarker research is access to large datasets to achieve sufficient power and significance when ascertaining associations between retinal measures and clinical characterisation of disease. Crucially, the vascular changes that appear can affect arteries and veins differently. An essential part of automatic systems for retinal morphology quantification and biomarker extraction is, therefore, a computational method for classifying vessels into arteries and veins. Artery-vein classification enables the efficient extraction of biomarkers such as the Arteriolar to Venular Ratio, which is a well-established predictor of stroke and other cardiovascular events. While structural parameters of the retinal vasculature such as vessels calibre, branching angle, and tortuosity may individually convey some information regarding specific aspects of the health of the retinal vascular network, they do not convey a global summary of the branching pattern and its state or condition. The retinal vascular tree can be considered a fractal structure as it has a branching pattern that exhibits the property of self-similarity. Fractal analysis, therefore, provides an additional means for the quantitative study of changes to the retinal vascular network and may be of use in detecting abnormalities related to retinopathy and systemic diseases. In this thesis, new developments to fully automated retinal vessel classification and fractal analysis were explored in order to extract potential biomarkers. These novel processes were tested and validated on several datasets of retinal images acquired with fundus cameras. The major contributions of this thesis include: 1) developing a fully automated retinal blood vessel classification technique, 2) developing a fractal analysis technique that quantifies regional as well as global branching complexity, 3) validating the methods using multiple datasets, and 4) applying the proposed methods in multiple retinal vasculature analysis studies.

Antalet patienter med sjukdomen diabetes förväntas öka vilket kommer innebära att ett ännu större antal patienter behöver screenas för att upptäcka diabetesretinopati. Syftet med den här pilotstudien var att beskriva patienters erfarenheter av screening för diabetesretinopati på en ögonmottagning. Pilotstudien utformades efter en kvalitativ induktiv ansats och data samlades in genom semistrukturerade intervjuer. Materialet bearbetades genom kvalitativ innehållsanalys. De huvudkategorier som framkom var: trygghet, informationens betydelse, tillgänglighetens betydelse, oro för undersökningsresultatet och dess konsekvenser samt obehagligt och tidskrävande. Resultatet visade på att det var viktigt för informanterna med screening för diabetesretinopati. Det var en trygghet att få gå på kontroller för att upptäcka komplikationer i tid. Det framkom att de kände en oro för att utveckla diabetesretinopati och vilken påverkan detta skulle ha på deras livssituation. Informanterna ville få ett tydligare resultat från undersökningen och att tillgängligheten förbättrades.  Det behövs vidare omvårdnadsforskning kring information, kunskap och ökad tillgänglighet vid screening för diabetesretinopati. Sådan forskning kommer att vara till hjälp för att förstå och därmed hitta strategier för att förbättra omvårdnaden för patienter med diabetes samt för att nå ut till dem som uteblir från screeningen för diabetesretinopati. / The number of patients with the disease diabetes expects to increase, which means that even a larger number of patients will need to be screened to detect diabetic retinopathy. The purpose of this study was to describe the experiences of screening for diabetes retinopathy at an ophtalmology department. The pilotstudy was developed by a qualitative inductive approach and data were collected through semi-structured interviews. The material was processed by qualitative content analysis. The main categories that emerged were: security, the importance of information, the importance of accessibility, concerns about the result and its consequences and uncomfortable and time-consuming. The result showed that screening for diabetes retinopathy was important for the informants. It was a security to check their eyes to detect complications in time. It was revealed that they felt a concern for complications due to diabetic retinopathy and what effect this would have on their lives. The informants wanted to get a clearer result of the examination and that the availability would improve. Further nursing research about information, knowledge and increased availability in screening for diabetes retinopathy is needed. Such research would be helpful to improve care patients with diabetes, and to find strategies for reaching out to those who fail to attend screening for diabetes retinopathy.

Orientador: Alexandre Lima de Andrade / Banca: Alexandre Lima de Andrade / Banca: Flavia de Rezende Eugênio / Banca: Alexandre Pinto Ribeiro / Resumo: A leishmaniose visceral (LV) canina caracteriza-se por uma enorme variabilidade de manifestações clínicas, dentre elas, lesões dermatológicas e oculares. Poucos são os estudos com as alterações do segmento posterior de olhos de cães acometidos pela doença, devido, principalmente, à opacidade do segmento anterior. O objetivo do trabalho foi avaliar e descrever as principais alterações fundoscópicas e eletrorretinográficas observadas em cães naturalmente acometidos por LV, antes e após o tratamento com a miltefosina. Foram selecionados oito cães, que não apresentavam outras doenças infecciosas ou vasculares, e apresentassem meios oculares transparentes. Utilizaram-se registros fotográficos do segmento posterior e a avaliação da funcionalidade da retina através da eletrorretinografia (ERG). Os achados de fundoscopia incluíram atenuação vascular, hiperrefletividade, pigmentação retiniana, embainhamento vascular, hiperpigmentação peripapilar, hemorragia sub-retiniana, turbidez vítrea, papiledema e tortuosidade vascular. Todos os animais se beneficiaram clinicamente da terapêutica medicamentosa, não sendo mais encontradas hemorragia sub-retiniana e turbidez vítrea após tratamento, e somente um animal permanecia com a lesão de embainhamento vascular. A avaliação dos registros de ERG mostrou diminuição da amplitude de onda "b" nas respostas de bastonetes e máxima resposta entre os momentos. Conclui-se que a LV promove alterações no fundo de olhos de cães antes mesmo da ocorrência de ... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: Visceral leishmaniasis (VL) canine is characterized by a huge variability of clinical manifestations, among them skin and eye damage. Few studies of the changes of the posterior segment of an eye of dogs affected by the disease, mainly due to the opacity of the anterior segment. The objective was to assess and describe the main fundus and ERG changes observed in dogs naturally affected by LV before and after treatment with miltefosine. Eight dogs were selected which showed no vascular or other infectious diseases, and to produce clear ocular media. They used photographic records of the posterior segment and evaluation of retinal function by electroretinography. The findings included fundus vascular attenuation, increased reflective, retinal pigmentation, vascular sheathing, peripapillary hyperpigmentation, subretinal hemorrhage, atrophy of the optic disk, vitreous turbidity, papilledema, vascular tortuosity. All animals were clinically benefit of drug treatment, no longer found bleeding subretinal and vitreous turbidity after treatment, only one animal was to vascular sheathing. The evaluation of the ERG records showed decreased amplitude wave "b" in the responses of rods and maximum response between times. It concludes that the LV promotes changes in the dog's eyes background even before the occurrence of visual loss and miltefosine is effective in treating the disease, but provided few changes of fundus findings and ERG. / Mestre

Cette thèse a pour objet l’étude de nouvelles méthodes de traitement d’image appliquées à l’analyse d’images numériques du fond d'œil de patients diabétiques. En particulier, nous nous sommes concentrés sur le développement algorithmique supportant un système de dépistage automatique de la rétinopathie diabétique. Les techniques présentées dans ce document peuvent être classées en trois catégories: (1) l’évaluation et l’amélioration de la qualité d’image, (2) la segmentation des lésions, et (3) le diagnostic. Pour la première catégorie, nous présentons un algorithme rapide permettant l’estimation numérique de la qualité d’une seule image à partir de caractéristiques extraites de la vascularisation et de la couleur du fond d'œil. De plus, nous démontrons qu’il est possible d’augmenter la qualité des images et de supprimer les artefacts de réflexion en fusionnant les informations extraites de plusieurs images d’un même fond d'œil (images capturées en changeant le point d’attention regardé par le patient). Pour la deuxième catégorie, deux familles de lésion sont ciblées: les exsudats et les microanévrysmes. Deux nouveaux algorithmes pour l’analyse des images du fond d'œil sont proposés et comparés avec les techniques existantes afin de démontrer leur efficacité. Dans le cas des microanévrismes, une nouvelle méthode basée sur la transformée de Radon a été développée. Dans la dernière catégorie, nous présentons un algorithme permettant de diagnostiquer la rétinopathie diabétique et les œdèmes maculaires en analysant les lésions détectées par segmentation d’image; à partir d’une seule image, notre algorithme permet de diagnostiquer une rétinopathie diabétique et/ou un œdème maculaire en ~ 22 secondes sur une machine à 1,6 GHz avec 4 Go de RAM; de plus, nous montrons les premiers résultats de notre algorithme de détection d'œdème maculaire basé sur des images du fond d'œil multiples, qui peut éventuellement permettre d’identifier le gonflement de la macula même si aucune lésion n’est visible. / In this Ph.D. thesis, we study new methods to analyse digital fundus images of diabetic patients. In particular, we concentrate on the development of the algorithmic components of an automatic screening system for diabetic retinopathy. The techniques developed can be categorized in: quality assessment and improvement, lesion segmentation and diagnosis. For the first category, we present a fast algorithm to numerically estimate the quality of a single image by employing vasculature and colour-based features; additionally, we show how it is possible to increase the image quality and remove reflection artefacts by merging information gathered in multiple fundus images (which are captured by changing the stare point of the patient). For the second category, two families of lesion are targeted: exudate and microaneurysms; two new algorithms which work on single fundus images are proposed and compared with existing techniques in order to prove their efficacy; in the microaneurysms case, a new Radon transform-based operator was developed. In the last diagnosis category, we have developed an algorithm that diagnoses diabetic retinopathy and diabetic macular edema based on the lesions segmented; starting from a single unseen image, our algorithm can generate a diabetic retinopathy and ma cular edema diagnosis in _22 seconds on a 1.6 GHz machine with 4 GB of RAM; additionally, we show the first results of a macular edema detection algorithm based on multiple fundus images, which can potentially identify the swelling of the macula even when no lesions are visible.

No description available.

This master’s thesis is aimed at registration of frames of retinal fundus video using phase corre- lation. An introduction describes general research in topic of retinal fundus, eye movements, diff erent approaches for image registration, phase correlation and examples of phase corre- lation applications. The second, practical part of master’s thesis, is dedicated to description of the proposed algorithm for registration of frames of retinal fundus video. The description of the proposed algorithm is divided into three parts. First two parts describe how frames of retinal fundus video are rated in terms of suitability for registration. Third part describes image registration algorithm itself. In conclusion, the accuracy of algorithm and computational time are evaluated.