Class of 2010 Abstract / OBJECTIVES: This is a selective systematic review of the methods used to monitor for the ocular adverse effects of chronic hydroxychloroquine use. This was done to describe the screening methods for detecting retinal toxicity and the recommendations for early detection of hydroxychloroquine associated retinopathy. METHODS: A literature search of OVID-MEDLINE and the Evidence Based Medicine (EBM) search database in the AHSL website were performed for the date range October 1999 to October 2009. Articles were selected based on content related to our purpose statement. Each article must have had at least one or more ophthalmic screening test including: fundus photography, Amsler grid, perimetry, color vision, and multifocal electroretinography. RESULTS: The search results returned a total of 67 articles. A total of twelve articles were selected for review. A total of 959 human subjects were studied and 22 patients had reported retinal changes attributed to hydroxychloroquine. Nine of the eleven studies that included mfERG recommended this specific test for monitoring for hydroxychloroquine induced retinopathy. Only six of the studies recommended the frequency of testing. The most common recommendation was to test at baseline and then at least annually. CONCLUSIONS: The results suggest the mfERG is the most sensitive and objective exam for early documentation of toxic retinopathy. In addition baseline and annual testing was suggested most often. The data also suggest that high risk patients be followed more closely as the most severe and irreversible damage occurs in this population.

No description available.

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Diss. (sammanfattning) Stockholm : Karol. inst. / Härtill 6 uppsatser.

Thesis (Ph. D.)--University of Oklahoma. / Bibliography: leaves 132-156.

Diabetic Retinopathy (DR) is a disorder of the retinal vasculature. It develops to some degree in nearly all patients with long-standing diabetes mellitus and can result in blindness. Screening of DR is essential for both early detection and early treatment. This thesis aims to investigate automatic methods for diabetic retinopathy detection and subsequently develop an effective system for the detection and screening of diabetic retinopathy. The presented diabetic retinopathy research involves three development stages. Firstly, the thesis presents the development of a preliminary classification and screening system for diabetic retinopathy using eye fundus images. The research will then focus on the detection of the earliest signs of diabetic retinopathy, which are the microaneurysms. The detection of microaneurysms at an early stage is vital and is the first step in preventing diabetic retinopathy. Finally, the thesis will present decision support systems for the detection of diabetic retinopathy and maculopathy in eye fundus images. The detection of maculopathy, which are yellow lesions near the macula, is essential as it will eventually cause the loss of vision if the affected macula is not treated in time. An accurate retinal screening, therefore, is required to assist the retinal screeners to classify the retinal images effectively. Highly efficient and accurate image processing techniques must thus be used in order to produce an effective screening of diabetic retinopathy. In addition to the proposed diabetic retinopathy detection systems, this thesis will present a new dataset, and will highlight the dataset collection, the expert diagnosis process and the advantages of the new dataset, compared to other public eye fundus images datasets available. The new dataset will be useful to researchers and practitioners working in the retinal imaging area and would widely encourage comparative studies in the field of diabetic retinopathy research. It is envisaged that the proposed decision support system for clinical screening would greatly contribute to and assist the management and the detection of diabetic retinopathy. It is also hoped that the developed automatic detection techniques will assist clinicians to diagnose diabetic retinopathy at an early stage.

Background: The International Diabetes Federation estimates that the number of adults with diabetes in Africa will increase by 98% by the year 2030. The importance of diabetic retinopathy as a cause of blindness has increased because of longevity and a decline in the other preventable causes of blindness in developing countries. Retinopathy diagnosed early, followed closely, and treated timeously with retinal laser therapy, prevents blinding retinopathy. The objective of the study is to determine the prevalence of Diabetic Retinopathy, its determinants and the acceptability as well as accessibility of the screening service by patients. Methods: The study is a cross-sectional study conducted at Gaborone diabetic retinopathy screening clinic. Convenience sampling was used where every eligible patient that arrived for DR screening and had consented was included in the study. Basic descriptive statistics of the study sample were reported and a multivariate analysis was performed with DR as the outcome of interest. Results: A total of 220 participants attended the clinic between 12th of January and 6th of February 2015. The mean age of the participants was 55.96 (p=0.32) years and females comprised the majority 65.45% (n= 144, p=0.33)) of participants. A fifth of the participants (n=43, p=0.67) felt they had poor knowledge of diabetes and 25.91% (n=57, p=0.96) stated they did not understand the purpose of screening. Only 63.64% (n=140, p=0.46) reported to always being compliant with their medication and compliance did not differ significantly between those who had retinopathy and those who did not. Traditional medicine use was reported in 16.36% of the participants (n=36, p=0.33). Diabetic Retinopathy was found in 31.82% (n=70) of the population and of those, 3 participants (1.36%) had referable DR. Maculopathy was found in 21.82% (n=48) of participants. Increasing household number and years living with DM were the only variables found to have a significant association with development of diabetic retinopathy. Conclusion: The prevalence of diabetic retinopathy has increased in our population compared to previous studies. The number of Diabetics attending the DR screening service in Gaborone has also increased but continuous diabetes health education cannot be over emphasized. Incorporation of local cultural values into the overall management of the disease is the best way to increase patient compliance.

Diabetes is a disease characterized by high blood glucose levels that result from a defect in the body’s inability to produce or utilize insulin. This disease increases the risk of long-term health problems and affects multiple organ systems; one complication being diabetic retinopathy (DR) that causes changes in the blood vessels of the retina. Diabetic retinopathy is the leading cause of blindness in the working age population. Early events in the pathogenesis of diabetic retinopathy are characterized by retinal vascular cell loss and excess retinal capillary leakage. Studies have shown that the retinal vascular cell loss occurs by programmed cell death while excess permeability develops at least in part through compromised tight junctions. Studies, including those from our laboratory, have also established that high glucose or diabetes reduces a specific protein, Cx43, found in intercellular communication channels or gap junctions, and contributes to the development of programmed cell death. It is currently unknown if there is an association between high glucose- or diabetes-induced Cx43 downregulation and excess permeability. Importantly, previous studies have shown that reduced Cx43 can promote excess permeability, but the mechanism underlying this phenomenon is not well understood. In this study, the effects of reduced Cx43 expression on proteins involved in cell-cell adhesion, or tight junctions, was examined. Specifically, experimentally induced Cx43 downregulation by a gene silencing technique affected the expression of tight junction proteins (ZO-1, occludin, claudin-5) in rat retinal endothelial cells. ZO-1 and occludin protein levels were decreased while claudin-5 levels were increased. In addition, permeability was increased when Cx43 was downregulated. These observations suggest that expression levels of Cx43 regulate barrier characteristics by influencing the expression of tight junction proteins. Findings from this study provide an insight into how high glucose-induced Cx43 downregulation compromises endothelial barrier characteristics through modulation of tight junction proteins. / 2031-01-01

To investigate the possibility that chronic diabetes mellitus was related to specific neuropsychological deficits, cognitive functioning was measured in subjects with diabetic retinopathy (without secondary disabilities), and in subjects classified as normal blind adults (also without secondary disabilities). The scores for the two groups were then compared.

PURPOSE: Ischemic retinopathies such as diabetic retinopathy (DR), retinal vein occlusions (RVO), and age-related macular degeneration (AMD) are ocular diseases caused by abnormal changes in the microvasculature that results in ischemia. This is often followed by a secondary phase characterized by pathological neovascularization and leakage of fluid, which contributes to a loss of visual acuity in affected patients. Anti-VEGF therapy, the current standard of treatment for ischemic retinopathies, is invasive, costly, and lacks a known treatment period. Supplemental oxygen provides the therapeutic potential of not only oxygenating hypoxic retinal cells, but also reducing the neovascularization and edema associated with many ischemic retinopathies through the downregulation of proangiogenic and pro-inflammatory cytokines.The objective of this study is to understand the biochemical underpinnings of treating ischemic retinopathies with hyperoxia. The elucidation of the effect hyperoxia on the molecular level may help guide the development of future studies regarding this novel treatment. METHODS: 68 undiluted vitreous samples were obtained during pars plana vitrectomy (PPV) and the concentration analysis of 34 proteins was analyzed using the Bio-Plex Pro Human Cancer Biomarker Assay. Vitreous samples were divided into three groups: (1) eyes of patients who underwent PPV for epiretinal membrane peeling (ERMP) and/or macular hole (MH) with no history of diabetes mellitus (non-DM group); (2) eyes of patients who underwent PPV for ERMP and/or MH with a history of diabetes or nonproliferative diabetic retinopathy (DM group); (3) eyes of patients who underwent PPV for proliferative diabetic retinopathy (PDR group). Mann-Whitney U tests were performed to compare the biomarker concentrations between the three groups. RESULTS: Numerous growth factors and inflammatory cytokines were significantly upregulated between the non-DM and PDR groups - Angiopoietin-2, EGF, Endoglin, G-CSF, HB-EGF, HGF, PDGF, PIGF, sHER2/neu, TIE-2, VEGF-A, VEGF-D, IL-18, IL-6, IL-8, PECAM-1, sCD40L, SCF, sFASL, sIL-6Ra, TNF-⍺, Leptin, PAI-1, and uPA. A literature search of these proteins revealed many to be directly activated by HIF-1 transcription factor, which is the "master switch" for genes transcribed during a hypoxic event. CONCLUSION: The abundance of proangiogenic and pro-inflammatory factors in PDR that are also upregulated by HIF-1 demonstrate the potential for using hypoxia to treat PDR (and other ischemic retinopathies) through the reduction of HIF-1. This study also shows the wide variability in the expression levels of these proteins which helps provide a better understanding of their degree of involvement in the pathogenesis of ischemic retinopathies. / 2021-06-14T00:00:00Z