Orientador: Anderson de Rezende Rocha / Dissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Computação / Made available in DSpace on 2018-08-23T17:47:21Z (GMT). No. of bitstreams: 1 Pires_Ramon_M.pdf: 4429324 bytes, checksum: 4e4015bc2131a1f1a5e8aa215f24d98f (MD5) Previous issue date: 2013 / Resumo: A Retinopatia Diabética (RD), complicação provocada pela diabetes, se manifesta por meio de diferentes lesões que possuem suas especificidades. Estas especificidades são exploradas na literatura como estratégia para representação, proporcionando uma discriminação satisfatória entre imagens de pacientes normais e doentes. No entanto, por estarem fortemente atrelada _as características visuais de cada anomalia, a detecção de lesões distintas exige abordagens distintas. Neste trabalho, apresentamos um arcabouço geral cujo objetivo é automatizar o procedimento de análise de imagens de fundo de olho. O trabalho é dividido em quatro etapas: avaliação de qualidade, detecção de lesões individuais, triagem e verificação de necessidade de consulta. Na primeira etapa, aplicamos diferentes técnicas de caracterização de imagens para avaliar a qualidade das imagens por meio de dois critérios: definição de campo e detecção de borramentos. Na segunda etapa deste trabalho, propomos a continuação de um trabalho anterior desenvolvido pelo nosso grupo, no qual foi aplicado um método unificado na tentativa de detecção de lesões distintas. No nosso método para detecção de qualquer lesão, exploramos diferentes alternativas de representação em baixo nível (extração densa e esparsa) e médio nível (técnicas de coding/pooling para sacolas de palavras visuais) objetivando o desenvolvimento de um conjunto eficaz de detectores de lesões individuais. As pontuações provenientes de cada detector de lesão, obtidas para cada imagem, representam uma descrição de alto nível, ponto fundamental para a terceira e a quarta etapas. Tendo em mãos um conjunto de dados descritos em alto nível (pontuações dos detectores individuais), propomos, na terceira etapa do trabalho, a aplicação de técnicas de fusão de dados para o desenvolvimento de um método de detecção de múltiplas lesões. A descrição em alto nível também é explorada na quarta etapa para o desenvolvimento de um método eficaz de avaliação de necessidade de encaminhamento a um oftalmologista no intervalo de um ano, visando evitar que o médico seja sobrecarregado, bem como dar prioridade a pacientes em estado urgente / Abstract: Diabetic Retinopathy (DR), a common complication caused by diabetes, manifests through deferent lesions that have their particularities. These particularities are explored in the literature as methods for representation, providing a satisfactory discrimination between healthy/diseased retinas. However, by being strongly linked to the visual characteristics of each anomaly, the detection of distinct lesions requires distinct approaches. In this work, we present a general framework whose objective is to automate the eye-fundus image analysis. The work comprises four steps: image quality assessment, DR-related lesion detection, screening, and referral. In the first step, we apply characterization techniques to assess image quality by two criteria: field definition and blur detection. In the second step of this work, we extend up a previous work of our group which explored a unified method for detecting distinct lesions in eye-fundus images. In our approach for detection of any lesion, we explore several alternatives for low-level (dense and sparse extraction) and mid-level (coding/pooling techniques of bag of visual words) representations, aiming at the development of an effective set of individual DR-related lesion detectors. The scores derived from each individual DR-related lesion, taken for each image, represent a high-level description, fundamental point for the third and fourth steps. Given a dataset described in high-level (scores from the individual detectors), we propose, in the third step of the work, the use of machine learning fusion techniques aiming at the development of a multi-lesion detection method. The high-level description is also explored in the fourth step for the development of an effective method for evaluating the necessity of referral of a patient to an ophthalmologist in the interval of one year, avoiding overloading medical specialist with simple cases as well as give priority to patients in an urgent state / Mestrado / Ciência da Computação / Mestre em Ciência da Computação

Type 2 diabetes mellitus (T2DM) is one of the leading causes of death from worldwide non-communicable diseases. The prevalence of diabetes in the Mexico (MX)-United States border states exceeds the national rate in both countries. The economic burden of diabetes, due to decreased productivity, disability, and medical costs, is staggering and increases significantly when T2DM-related complications occur. The purpose of this study was to use a modified behavioral risk factor surveillance system (BRFSS) to describe the T2DM self-management behaviors, diabetes care, and health perception of a convenience sample of adults with T2DM in Monterrey, MX. This cross-sectional study design, with convenience sampling, was conducted with a convenience sample (n = 351) of adults in the metropolitan area of Monterrey, MX who self-reported a diagnosis of T2DM. Potential participants were recruited from local supermarkets. Twenty-six diabetes and health-related items were selected from the BRFSS and administered in face-to-face interviews by trained data collectors. Data analysis was conducted using descriptive statistics. The mean age was 47 years, and the mean length of time with T2DM was 12 years. The majority was taking oral medication and 34% required insulin. Daily self-monitoring of feet was performed by 56% of the participants; however, only 8.8% engaged in blood glucose self-monitoring. The mean number of health-care provider visits was 9.09 per year, and glycated hemoglobin level (HbA1c) was assessed 2.6 times per year. Finally, only 40.5% of the participants recalled having a dilated eye exam. We conclude the modified BRFSS survey administered in a face-to-face interview format is an appropriate tool for assessing engagement in T2DM self-management behaviors, diabetes care, and health perception. Extension of the use of this survey in a more rigorous design with a larger scale survey is encouraged.

Diabetic retinopathy (DR) is becoming a global health concern, which causes the loss of vision of most patients with the disease. Due to the vast prevalence of the disease, the automated detection of the DR is needed for quick diagnoses where the progress of the disease is monitored by detection of exudates changes and their classifications in the fundus retina images. Today in the automated system of the disease diagnoses, several image enhancement methods are used on original Fundus images. The primary goal of this thesis is to make a comparison of three of popular enhancement methods of the Mahalanobis Distance (MD), the Histogram Equalization (HE) and the Contrast Limited Adaptive Histogram Equalization (CLAHE). By quantifying the comparison in the aspect of the ability to detect and classify exudates, the best of the three enhancement methods is implemented to detect and classify soft and hard exudates. A graphical user interface is also adopted, with the help of MATLAB. The results showed that the MD enhancement method yielded better results in enhancement of the digital images compared to the HE and the CLAHE. The technique also enabled this study to successfully classify exudates into hard and soft exudates classification. Generally, the research concluded that the method that was suggested yielded the best results regarding the detection of the exudates; its classification and management can be suggested to the doctors and the ophthalmologists.

Purpose: Facing the lack of time, busy retina consultants should be aware of how the patients would prefer that time is spent and whether they wish the specialist to talk more at the expense of other medical activities. Methods: 810 persons with diabetes were asked to divide the time of 10 min between examination, consultation and treatment when envisioning a real-life scenario of diabetic retinopathy (NCT02311504). Results: With the increasing duration of diabetes, patients wanted significantly more time for diagnostics (p = 0.028), while age was found to be associated with less time for treatment (p = 0.009). Female subjects tended to prefer only little more time for talking (p = 0.051) in comparison with males, who slightly favored therapy (p = 0.025). Conclusions: The large majority recognized the need for diagnostics in their allocation of time. If individual patients are confronted with the health care perspective of time constraints, this might improve the understanding of prioritization.

PURPOSE: Retinal and choroidal ischemic retinopathies such as retinal-vein occlusion (RVO), diabetic retinopathy (DR), and age-related macular degeneration (AMD) are ocular diseases caused by abnormal changes in the microvasculature. The ischemia can lead to macular edema or neovascularization, which can affect vision. Intravitreal injections (IVI) of anti-vascular endothelial growth factor (anti-VEGF) can help to reduce macular edema and improve visual acuity. Lost to follow-up (LTFU) after anti-VEGF injections increases the risk of vision loss in patients with RVO, DR, and AMD. METHODS: Patients scheduled for an IVI of anti-VEGF between September 2009 and September 2019 with either RVO, DR, or AMD were included in the analysis. LTFU was defined as missing an appointment without another evaluation for at least one interval exceeding 180 days. All patients were seen by a single provider at an urban, hospital-based, single-site retina practice in Boston, MA. RESULTS: Among the 698 patients (mean [SD] age, 70.23 [14.2] years; 373 [53.4%] female) identified as receiving an IVI, 121 (17.3%) were LTFU. Age was not found to be statistically different between the LTFU and not LTFU groups (mean difference, -1.67; 95% CI, -4.66¬–1.32; P=.27). Odds of LTFU was lower among patients with AMD (odds ratio [OR], 0.57; 95% CI, 0.36-0.92; P=.02). Odds of LTFU was greater among patients with Medicaid insurance (OR, 2.31; 95% CI, 1.22-4.33; P=.01), compared with patients with Medicare insurance. A trend towards higher risk of LTFU was seen in patients with DR (OR, 1.42; 95% CI, 0.94-2.15; P=.09) and a toward lower risk in patients with two or more eye diseases (OR, 0.53; 95% CI, 0.24-1.15; P=.10). Medicaid insurance was the only significant (P=.02) independent risk factor of LTFU in the multivariate regression. CONCLUSION: We found a high rate of LTFU after anti-VEGF injections among patients with RVO, DR, AMD, and identified risk and protective factors associated with LTFU among this population. Although our results may not be generalizable, data on LTFU in a clinical practice setting are needed to understand the scope of the problem so that interventions may be designed to improve outcomes.

Bakgrund: Alla diabetiker erbjuds screening av ögonbottnen för diabetesretinopati så att den ska kunna upptäckas och behandlas i tid. Enligt Region Skånes riktlinje för screening av diabetesretinopati kan en traditionell funduskamera eller en wide field ka-mera som täcker 80 procent av näthinnan användas, något som hittills enbart Optos kan. Syftet med studien var att undersöka hälso- och sjukvårdspersonalens uppfattningar om Optos i samband med screening av diabetesretinopati. Metod: Femton ögonmottagningar visade sig använda Optos. Av dessa deltog tio i tvär-snittsenkätstudien. En webbenkät utformades bestående av öppna och multiple-choice frågor. Fritextsvaren analyserades med innehållsanalys som resulterade i ett antal kategorier och respektive svarsfrekvenser. Resultat: Optos uppfattades som en användar- och patientvänlig metod vilken kan öka tillgängligheten. Skärpan i Optomap uppfattades vara god, men något sämre än i fun-dusbilderna. Några uppfattade Optos som en bra metod för screening av diabetesretino-pati. Andra ansåg att användning av Optos skulle innebära en patientrisk. Då den sämre centrala skärpan skulle kunna leda till underdiagnosticering alternativt att Optomaps stora täckningsgrad skulle kunna vara anledning till en överdiagnosticering. Ett stort externt bortfall begränsar studieresultatets generaliserbarhet. Slutsats: Uppfattningar huruvida Optos anses vara lämpligt att användas i samband med screening av diabetesretinopati går isär och lämpliga användningsområden behöver definieras närmare. / Background: Screening for retinopathy is offered to all diabetics to allow detection and treatment on time. According to a regional guideline for screening of diabetic retino-pathy traditional fundus camera may be used or a wide field camera picturing 80 % of the retina, something nowadays only Optos can do. Aim of this study was to investigate health personnel’s attitude towards Optos in the context of diabetic retinopathy screening. Methods: Fifteen eye clinics using Optos were identified and ten of those took part in this survey. Self-administered questionnaires with multiple-choice and open questions were used. Free text answers were analysed using context analysis with determination of frequencies for the evolving categories. Results: Optos was perceived as being user and patient friendly, as well as being able to increase accessibility. Optomap had good but digital fundus pictures better perceived acuity. According to some was Optos a good method for screening of diabetic retino-pathy and inappropriate according to others apprehending a patient risk. Expecting underdiagnosis due to less central acuity alternatively overdiagnosis due to Optomap covering 80 % of the retina. High drop-out rate eventuates limited validity. Conclusions: Diverging attitudes emerged whether Optos is suitable for screening of diabetic retinopathy. Its appropriate use needs to be defined in further detail.

Bakgrund: Diabetes Mellitus är en sjukdom med potentiellt allvarliga konsekvenser som drabbar ett ökande antal människor runt om i världen. En av de ögonkomplikationer som kan drabba diabetiker är diabetesretinopati. Regelbunden ögonbottenscreening kan avslöja förändringar i ögonbotten innan de ger symtom eller synhotande skador som kan vara irreversibla. Tidig diagnos och behandling minskar risken för synnedsättning och blindhet, trots detta uteblir många diabetiker från planderad ögonbottenscreening.          Syfte: Syftet var att belysa erfarenheter som påverkar följsamheten vid ögonbottenscreening hos patienter med diabetes.                                                  Metod: En litteraturöversikt med kvalitativa studier utfördes.                  Resultat: Översikten resulterade i fyra huvudteman; information,ekonomiska aspekter, personliga erfarenheter och erfarenhet vid ögonbottenscreening samt i elva underteman. De viktigaste faktorerna som framkom av studien var bristande information, ekonomi, transportproblematik samt besvär av pupillvidgande ögondroppar.                Slutsats: Denna studie har identifierat faktorer och erfarenheter som påverkar följsamheten till ögonbottenscreening vilket kan ge möjlighet till en bättre förståelse för patienternas behov och till ett förbättrat samarbete mellan olika vårdinstanser. / Background: Diabetes Mellitus is a common disease with potentially serious con­sequences that affects an increasing number of people worldwide. One of the comp­lications that can affect the eye of a patient with diabetes is diabetic retinopathy. Regular retinal screening can reveal early signs of diabetic retinopathy before any irreversible sight threatening retinal complications have developed. Early diagnosis and treatment decrease the risk for visual impairment and blindness, despite this fact many patients do not attend this examination.                                                                          Aim: The aim was to illuminate experiences that affects compliance to retinal screening among patients with diabetes. Method: A literature review including qualitative studies was conducted. Results: The results from the review showed four main themes; information, economic aspects, personal experiences and experience from retinal screening as well as eleven subthemes. The main subjects that emerged were lack of information, economy, transportation problems and inconvenience of mydriatic eye drops. Conclusion: This literature review has identified factors and experiences that affects compliance to retinal screening. This can provide an opportunity for a better under­standing of patients’ needs and for improved collaboration between healthcare institutions

Patient nonadherence to physicians' prescribed therapeutic regimen is the greatest challenge in the effective treatment of patients with diabetes worldwide. Scientific evidence has revealed that nonadherence to prescribed medication could result in diabetic complications such as cardiovascular disease, retinopathy, nephropathy, and neuropathic diabetic foot ulcers. The purpose of this study was to explore predictive relationships between levels of adherence to antidiabetic medications, patient HbA1c levels, and diabetic complications among Jamaicans, an understudied population. The research question that guided this study was: Do the patient level of adherence and HbA1c levels have any predictive relationship with the severity of diabetic complications (cardiovascular disease, retinopathy, nephropathy and neuropathic foot ulcer) among Jamaicans after controlling for age and gender? The theory of planned behavior was used to guide the study. Data regarding diabetic complications were collected from 119 records during a cross-sectional review of patient dockets. Level of adherence was determined from an interviewer-administered Morisky 8-item adherence scale. A multiple regression analysis revealed that lower levels of patient adherence to treatment and higher HbA1c levels predicted greater severity of cardiovascular disease (p = .000; p = .000), retinopathy (p = .009; p =.090), nephropathy (p =.007; p =.001) and diabetic neuropathic foot ulcers (p =.027; p =.001). Findings from this study will contribute to the knowledge base on diabetic medication nonadherence and may encourage health care professionals to advocate for better medication adherence strategies among people with diabetes.

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ABSTRACT Effective drug delivery to ocular tissues is an unmet challenge that has significant potential to improve the treatment of ocular diseases. Whether the intended drug delivery target is the anterior or posterior segment, the eye’s efficient natural protection mechanisms prevent effective and sustained drug delivery. Anatomical and physiological barriers including the rapid tear turnover that effectively washes away topically applied drugs, the impermeable characteristics of the cornea, conjunctiva, and sclera, and the tight junctions in the blood-ocular barriers make conventional drug delivery methods ineffective. New materials that are able to overcome these barriers are essential to improving the sustained delivery of ophthalmic therapeutics to the intended targets within the eye. This thesis will explore two polymeric drug delivery systems that have the potential to improve therapeutic delivery to ocular tissues. Chapter 1 will discuss the anatomical and physiological barriers to ophthalmic drug delivery and overview current research in this area. Chapter 2 will discuss the synthesis of N-isopropylacrylamide-based copolymers with adjustable gelation temperatures based on composition and molecular weight. Chapter 3 will discuss further development of these copolymers into an injectable, thermoresponsive, and resorbable polymeric drug delivery system intended for the treatment of diseases in the posterior segment. Chapter 4 will discuss the development of mucoadhesive polymeric micelle nanoparticles based on phenylboronic acid intended for topical administration of ophthalmic therapeutics. Finally, Chapter 5 will provide an overview of potential future work on these materials that could further develop and broaden their therapeutic use. / Thesis / Master of Science in Biomedical Engineering