Doctor of Philosophy (PhD) / BACKGROUND: The accumulation of abnormal extracellular deposits beneath the retinal pigment epithelium characterises the pathology of early age-related macular degeneration. However, the histopathological threshold at which age-related changes become early AMD is not defined, and the effect of each of the deposits (basal laminar deposit and membranous debris) on disease progression is poorly understood. Evidence suggests that macrophages play a key role in the development of AMD lesions, but the influence of basal laminar deposit (BLamD) and membranous debris on the recruitment and programming of local macrophages has not been explored. Although evidence also suggests that inflammation and innate immunity are involved in AMD, the significance of anti-retinal autoantibodies to disesase pathogenesis is not known. AIMS: (i) To determine the histopathological threshold that distinguishes normal ageing from early AMD; (ii) to determine the influence of BLamD and membranous debris on disease progression; (iii) to examine whether distinct early AMD phenotypes exist based on clinicopathological evidence; (iv) to determine the histopathological context in which Bruch’s membrane macrophages first found; (v) to examine the relationship between Bruch’s membrane macrophages and subclinical neovascularisation; (vi) to determine if the progressive accumulation of BLamD and membranous debris alters the immunophenotype of Bruch’s membrane macrophages and/or resident choroidal macrophages; (vii) to determine if the anti-retinal autoantibody profile differs significantly between normal individuals and those with early AMD, neovascular AMD or geographic atrophy; (viii) to examine whether baseline anti-retinal autoantibodies can predict progression to advanced AMD in individuals with early AMD; and (ix) to examine whether baseline anti-retinal autoantibodies can predict vision loss in individuals with neovascular AMD. METHODS:Clinicopathological studies were performed to correlate progressive accumulation of BLamD and membranous debris to fundus characteristics and visual acuity, as well as to sub-macular Bruch’s membrane macrophage count. Immunohistochemical studies were perfomed to determine whether the presence of BLamD and membranous debris altered the programming of Bruch’s membrane or resident choroidal macrophages. The presence of serum anti-retinal autoantibodies was determined by western blotting, and the association with disease progression examined in early and neovascular AMD. RESULTS: The presence of both basal linear deposit (BLinD) and a continuous layer of BLamD represents threshold early AMD histopathologically, which was seen clinically as a normal fundus in the majority of cases. Membranous debris accumulation appeared to influence the pathway of progression from early AMD to advanced AMD. Bruch’s membrane macrophages were first noted when a continuous layer of BLamD and clinical evidence of early AMD were present, and increased with the amount of membranous debris in eyes with thin BLamD. Eyes with subclinical CNV had high macrophage counts and there was some evidence of altered resident choroidal macrophage programming in the presence of BLamD and membranous debris. Serum anti-retinal autoantibodies were found in a higher proportion of early AMD participants compared with both controls and participants with neovascular AMD, and in a higher proportion of individuals with atrophic AMD compared to those with neovascular AMD. The presence of baseline anti-retinal autoantibodies in participants with early AMD was not associated with progression to advanced AMD. Participants with neovascular AMD lost more vision over 24 months if they had IgG autoantibodies at baseline compared to autoantibody negative participants. CONCLUSIONS: The finding that eyes with threshold early AMD appear clinically normal underscores the need to utilise more sophisticated tests to enable earlier disease detection. Clinicopathological evidence suggests two distinct early AMD phenotypes, which follow two pathways of AMD progression. Macrophage recruitment and programming may be altered by the presence of BLamD and membranous debris, highlighting the need to further characterise the biology of human resident choroidal macropahges. Anti-retinal autoantibodies can be found in both control and AMD sera, and future approaches that allow the examination of subtle changes in complex repertoires will determine whether they are involved in AMD disease pathogenesis.

Background: Diabetes mellitus and vascular diseases have a significant impact on the eye. / Aim: To determine the prevalence, risk factors, and racial/ethnic differences of major eye conditions, particularly retinal conditions, associated with diabetes and vascular diseases. / Scope: To date, the majority of studies have examined the association of retinal vascular calibre and diabetes in predominantly white Caucasian populations. Further elucidation of ethnic differences in effects of hyperglycaemia on early microvascular disease is relevant, particularly amongst Asians where diabetes is likely to see the largest increase in prevalence over the next decade. We therefore examined these findings from three Asian population-based studies, the Singapore Malay Eye Study (n=3280), Singapore Prospective Cohort Study and Singapore Cardiovascular Cohort Study 2 (n=3748). / Results: The prevalence of diabetic retinopathy in the Singapore Malay Eye Study was 35%, and associated with longer duration of diabetes, poorer glycemic and blood pressure control. More importantly, 9.0% had vision-threatening retinopathy, and retinopathy was found in 6.0% of people without diabetes. Retinal vascular calibre changes were incriminated in diseases such as diabetes and hypertension, independent of traditional cardiovascular risk factors. Wider venular calibre was independently associated with early age-related macular degeneration. We also found a novel association between peripheral artery disease and glaucoma, stronger in persons with diabetes, independent of vascular risk factors, supporting the vascular theory of glaucoma. / Implications: Subtle changes in retina, including retinal vascular calibre may be early markers of widespread microvascular changes in diabetes, resulting from chronic hyperglycaemia and other pathogenic processes. These results will have broad implications for understanding the impact of both microvascular and macrovascular complications of diabetes in the Asia Pacific region and targeting relevant therapeutic interventions.

Purpose: The main objective of the present study was the investigation of possible influence of lens opacification on macular pigment optical density (MPOD) measurements. Methods: 86 eyes of 64 patients (mean age 73.4(±8.3)years) were included in the study. MPOD was prospectively measured using one-wavelength reflection method (Visucam500, Carl Zeiss Meditec AG) before and after cataract extraction with implantation of a blue-light filtering intraocular lens (AlconSN60WF). The median of the maximum optical density (MaxOD) and the median of the mean optical density (MeanOD) measurements of macular pigment across the subject group were evaluated. Results: Statistically significant differences were noticed between pre-operative and post-operative measurements, the absolute values were generally lower after cataract extraction. The following median(lower/upper quartile) differences across the group were determined: MaxOD -33.8%(-46.2%/-19.1%), MeanOD -44.0%(-54.6%/-26.6%). Larger changes were observed in elderly patients (<70years of age: (n=25eyes) MaxOD -13.4%(-20.5%/3.6%), MeanOD -23.6%(-30.5%/-15.3%) versus patients ≥70years: (n=61eyes) MaxOD -40.5%(-53.2%/-30.1%), MeanOD -47.2%(-57.8%/-40.1%)) and in patients with progressed stage of cataract. MaxOD for lens opacification grade 1:(n=9eyes) -27.4%(-42.1%/-19.6%), 2:(n=26eyes) -35.0%(-44.2%/-25.3%), 3:(n=21eyes) -34.4%(-45.4%/-11.4%), 4:(n=25eyes) -32.6%(-53.2%/-6.4%) and 5:(n=5eyes) -53.5%(-61.7%/-38.7%) and MeanOD for cataract stage 1:(n=9eyes) -42.6%(-46.0%/-26.0%), 2:(n=26eyes) -44.1%(-51.8%/26.2%), 3:(n=21eyes) -45.7%(-54.7%/-24.7%), 4:(n=25eyes) -39.5%(-59.4%/-26.1%), 5:(n=5eyes) -57.0%(-66.1%/-51.4%). Conclusions: As established by comparison of pre- to post-operative measurements, cataract presented a strong effect on MPOD measured by one-wavelength reflection method. Particular care should therefore be taken when evaluating MPOD using this method in elderly patients with progressed stage of cataract. Future optimization of correcting parameters of scattered light and consideration of cataract influence may allow more precise evaluation of MPOD.

Patients with macular degeneration (MD) often fixate with a preferred retinal locus (PRL). Eye movements made while fixating with the PRL (in MD patients) has been observed to be maladaptive compared to those made while fixating with the fovea (normal sighted individuals). For example, in MD patients, PRL eye movements negatively affect fixation stability and re-fixation precision; consequently creating difficulty in reading and limits to their execution of other everyday activities. Abnormal eye movements from the PRL affect research on the physiological adaptations to MD. Specifically, previous research on cortical reorganization using functional magnetic resonance imaging (fMRI), indicates a critical need to accurately determine a MD patient's point of gaze in order to better infer existence of cortical reorganization. Unfortunately, standard MR compatible hardware eye-tracking systems do not work well with these patients. Their reduction in fixation stability often overwhelms the tracking algorithms used by these systems. This research investigates the use of an existing magnetic resonance imaging (MRI) based technique called Predictive Eye Estimation Regression (PEER) to determine the point of gaze of MD patients and thus control for fixation instability. PEER makes use of the fluctuations in the MR signal caused by eye movements to identify position of gaze. Engineering adaptations such as temporal resolution and brain coverage were applied to tailor PEER to MD patients. Also participants were evaluated on different fixation protocols and the results compared to that of the micro-perimeter MP-1 to test the efficacy of PEER. The fixation stability results obtained from PEER were similar to that obtained from the eye tracking results of the micro-perimeter MP-1. However, PEER's point of gaze estimations was different from the MP-1's in the fixation tests. The difference in this result cannot be concluded to be specific to PEER. In order to resolve this issue, advancements to PEER by the inclusion of an eye tracker in the scanner to run concurrently with PEER could provide more evidence of PEER's reliability. In addition, increasing the diversity of AMD patients in terms of the different scotoma types will help provide a better estimate of PEER flexibility and robustness.

Doctor of Philosophy (PhD) / BACKGROUND: The accumulation of abnormal extracellular deposits beneath the retinal pigment epithelium characterises the pathology of early age-related macular degeneration. However, the histopathological threshold at which age-related changes become early AMD is not defined, and the effect of each of the deposits (basal laminar deposit and membranous debris) on disease progression is poorly understood. Evidence suggests that macrophages play a key role in the development of AMD lesions, but the influence of basal laminar deposit (BLamD) and membranous debris on the recruitment and programming of local macrophages has not been explored. Although evidence also suggests that inflammation and innate immunity are involved in AMD, the significance of anti-retinal autoantibodies to disesase pathogenesis is not known. AIMS: (i) To determine the histopathological threshold that distinguishes normal ageing from early AMD; (ii) to determine the influence of BLamD and membranous debris on disease progression; (iii) to examine whether distinct early AMD phenotypes exist based on clinicopathological evidence; (iv) to determine the histopathological context in which Bruch’s membrane macrophages first found; (v) to examine the relationship between Bruch’s membrane macrophages and subclinical neovascularisation; (vi) to determine if the progressive accumulation of BLamD and membranous debris alters the immunophenotype of Bruch’s membrane macrophages and/or resident choroidal macrophages; (vii) to determine if the anti-retinal autoantibody profile differs significantly between normal individuals and those with early AMD, neovascular AMD or geographic atrophy; (viii) to examine whether baseline anti-retinal autoantibodies can predict progression to advanced AMD in individuals with early AMD; and (ix) to examine whether baseline anti-retinal autoantibodies can predict vision loss in individuals with neovascular AMD. METHODS:Clinicopathological studies were performed to correlate progressive accumulation of BLamD and membranous debris to fundus characteristics and visual acuity, as well as to sub-macular Bruch’s membrane macrophage count. Immunohistochemical studies were perfomed to determine whether the presence of BLamD and membranous debris altered the programming of Bruch’s membrane or resident choroidal macrophages. The presence of serum anti-retinal autoantibodies was determined by western blotting, and the association with disease progression examined in early and neovascular AMD. RESULTS: The presence of both basal linear deposit (BLinD) and a continuous layer of BLamD represents threshold early AMD histopathologically, which was seen clinically as a normal fundus in the majority of cases. Membranous debris accumulation appeared to influence the pathway of progression from early AMD to advanced AMD. Bruch’s membrane macrophages were first noted when a continuous layer of BLamD and clinical evidence of early AMD were present, and increased with the amount of membranous debris in eyes with thin BLamD. Eyes with subclinical CNV had high macrophage counts and there was some evidence of altered resident choroidal macrophage programming in the presence of BLamD and membranous debris. Serum anti-retinal autoantibodies were found in a higher proportion of early AMD participants compared with both controls and participants with neovascular AMD, and in a higher proportion of individuals with atrophic AMD compared to those with neovascular AMD. The presence of baseline anti-retinal autoantibodies in participants with early AMD was not associated with progression to advanced AMD. Participants with neovascular AMD lost more vision over 24 months if they had IgG autoantibodies at baseline compared to autoantibody negative participants. CONCLUSIONS: The finding that eyes with threshold early AMD appear clinically normal underscores the need to utilise more sophisticated tests to enable earlier disease detection. Clinicopathological evidence suggests two distinct early AMD phenotypes, which follow two pathways of AMD progression. Macrophage recruitment and programming may be altered by the presence of BLamD and membranous debris, highlighting the need to further characterise the biology of human resident choroidal macropahges. Anti-retinal autoantibodies can be found in both control and AMD sera, and future approaches that allow the examination of subtle changes in complex repertoires will determine whether they are involved in AMD disease pathogenesis.

Submitted by Franciele Moreira (francielemoreyra@gmail.com) on 2017-09-26T15:36:47Z No. of bitstreams: 2 Dissertação - Letícia Pinto Coelho Jorge - 2017.pdf: 7825738 bytes, checksum: 4eca5b3a59512770f7384ddd353ddb59 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Approved for entry into archive by Luciana Ferreira (lucgeral@gmail.com) on 2017-09-27T11:21:13Z (GMT) No. of bitstreams: 2 Dissertação - Letícia Pinto Coelho Jorge - 2017.pdf: 7825738 bytes, checksum: 4eca5b3a59512770f7384ddd353ddb59 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Made available in DSpace on 2017-09-27T11:21:13Z (GMT). No. of bitstreams: 2 Dissertação - Letícia Pinto Coelho Jorge - 2017.pdf: 7825738 bytes, checksum: 4eca5b3a59512770f7384ddd353ddb59 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Previous issue date: 2017-09-19 / Macula lutea is the region of the retina where the yellow pigments lutein and zeaxanthin are concentrated. Oxidative damage seems to be an important factor for exacerbation of several retinal diseases, such as age-related macular degeneration, and a protective role of macular pigment has been postulated. The quantitative study of macular pigment and its distribution are possible through the determination of macular pigment optical density (MPOD). The objective of this study was to determine the mean MPOD value in a sample of the Brazilian population and to evaluate the influence of sex, age, ethnicity, smoking history and refractive status on MPOD values in this sample. A cross-sectional study was performed. Forty-two healthy patients had both eyes photographed using Visucam 500 (Carl Zeiss Meditec, Jena, Germany) in combination with the MPOD module. Four variables were obtained: maximum MPOD, mean MPOD, MPOD volume and MPOD area. Demographic data and life habits were collected. The mean MPOD value in the studied population was 0.13 density unit ± 0.02. MPOD values were not influenced by gender, smoking history or refraction. MPOD values were significantly higher among black patients when compared to caucasians. There was a positive but low correlation between mean MPOD and age. / A mácula lútea é a região da retina onde se concentram os pigmentos amarelos luteína e zeaxantina. Acredita-se que eles sejam um fator de proteção para doenças atribuídas ao estresse oxidativo, como degeneração macular relacionada à idade. O estudo quantitativo do pigmento macular e sua distribuição são possíveis por meio da medida da densidade óptica de pigmento macular (MPOD). O objetivo deste trabalho foi determinar o valor médio de MPOD em uma amostra da população brasileira e avaliar a influência dos fatores sexo, idade, etnia, histórico de tabagismo e status refracional nos valores de MPOD nesta amostra. Foi realizado estudo tipo corte transversal. Quarenta e dois pacientes saudáveis tiveram ambos os olhos fotografados utilizando o Visucam 500 (Carl Zeiss Meditec, Jena, Alemanha) em combinação com o módulo MPOD. Quatro variáveis foram obtidas: MPOD máxima, MPOD média, volume de MPOD e área de MPOD. Foram colhidos dados demográficos e hábitos de vida. O valor médio de MPOD nesta amostra da população brasileira foi de 0,13 unidade de densidade ± 0,02. Os valores de MPOD não foram influenciados pelo sexo, histórico de tabagismo ou refração. Os valores de MPOD foram significativamente maiores entre os pacientes negros, quando comparados aos brancos. Encontrou-se uma correlação positiva, porém baixa, entre o valor de MPOD médio e a idade.

Orientadores: Antonia Paula Marques de Faria, Luis Alberto Magna / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Ciências Médicas / Made available in DSpace on 2018-08-20T01:20:07Z (GMT). No. of bitstreams: 1 Rim_PriscilaHaeHyun_D.pdf: 2205542 bytes, checksum: edfaaae7ed2a5aac688ce4f677a0d05a (MD5) Previous issue date: 2012 / Resumo: Introdução: A degeneração macular relacionada à idade (DMRI) é uma das principais causas de cegueira no mundo desenvolvido, acometendo indivíduos com mais de 65 anos. É uma condição multifatorial degenerativa e progressiva, ocasionando perda da visão central de um ou ambos os olhos e afetando a independência do idoso. Vários fatores de risco estão associados com essa condição incluindo fatores oculares, genéticos, demográficos, nutricionais, médicos e ambientais, mas não há estudo sistemático dos mesmos na população brasileira. Seria oportuno conhecê-los, considerando estabelecer eventuais estratégias para prevenção e diagnóstico precoce, pois apesar dos notáveis avanços na terapêutica da DMRI, o impacto socioeconômico dessa condição e de suas complicações tenderá a aumentar com o envelhecimento da população. Objetivos: Identificar os fatores de risco associados ao desenvolvimento e progressão da DMRI em uma população brasileira. Métodos: Realizado estudo transversal com grupo controle envolvendo 236 participantes com idade >50 anos incluindo 141 indivíduos afetados e 95 controles sem DMRI, todos pacientes assistidos no serviço de Oftalmologia do Hospital de Clínicas da Unicamp. Todos os participantes foram submetidos a exame oftalmológico completo incluindo fundoscopia, retinografia e angiografia e responderam a um questionário contendo perguntas sobre fatores demográficos, antecedentes médicos e oculares, história familial de DMRI, estilo de vida, hábitos de tabagismo e etilismo. Resultados: Dos 141 portadores de DMRI, 99 (71%) indivíduos apresentavam DMRI da forma avançada em pelo menos um dos olhos (57% DMRI neovascular e 13% atrofia geográfica) e 42 (30%) da forma inicial da doença (DMRI seca leve ou moderada). Os indivíduos afetados apresentaram acuidade visual (média de 20/200) significativamente menor do que os controles (média de 20/40) e mais de 50% dos pacientes com DMRI eram portadores de cegueira ou visão subnormal, (RR 9,89; 95%CI 3,79-25,81). Houve diferença significativa em relação aos fatores como: idade (RR 1.51; 95% CI: 0,88-2,58), história familial de DMRI (RR 6,58; 95% CI: 1,94-22,31), presença de doença cardiovascular (DCV) (RR 2,39; 95% CI: 1,08-5,28), altos níveis de colesterol plasmático (RR 1,49; 95% CI: 0,84-2,65) e sedentarismo (RR 1,39; 95% CI: 0,82-2,37). Não houve diferença significativa em relação ao sexo, IMC, catarata e/ou cirurgia de catarata, cor da pele, cor da íris, exposição solar, uso de antioxidantes, hipertensão arterial sistêmica, diabetes, tabagismo e etilismo na comparação entre pacientes e controles. Quanto ao tipo de DMRI, foi observada associação significativa em relação à presença de doença cardiovascular e a DMRI avançada (RR 2,29; 95% CI: 0,81-6,44). O nível de colesterol nos portadores de DMRI inicial foi mais alto que os de DMRI avançada (RR 1,67; 95% CI: 1,09-4,80). A correlação de 0,351 foi obtida na análise discriminante (stepwise), onde os fatores antecedentes familiais, idade, sedentarismo e dislipidemia foram considerados. Conclusão: Verificou-se na amostra estudada que os principais fatores de risco para DMRI são: idade, história familial de DMRI, doença cardiovascular, dislipidemia e sedentarismo. Entre estes fatores, indivíduos com DCV apresentaram risco aumentado para o desenvolvimento da forma avançada da DMRI e a hipercolesterolemia foi predominante naqueles com DMRI inicial. Como a DCV e a DMRI na forma avançada aparentemente apresentam vários fatores de risco em comum, foi feita recomendação final de que poderiam ser prevenidas conjuntamente por meio de programas de promoção da saúde do idoso envolvendo combate a fatores como hipertensão arterial, diabetes, obesidade (alto IMC), tabagismo, etilismo e maus hábitos alimentares, embora isoladamente não fossem estatisticamente significativos no presente estudo. Também foi destacado o papel da hereditariedade desta condição e a perspectiva de que membros das famílias de portadores sejam informados sobre risco de recorrência e medidas preventivas / Abstract: Background: Age-related macular degeneration (AMD) is one of the leading causes of irreversible blindness among individuals 65 years of age or older in developed countries. It is a degenerative and complex condition causing lost of central vision that impacts the independence of the elderly. A number of major risk factors for AMD have been identified worldwide, including genetic, demographic, nutritional, lifestyle, medical, environmental, and ocular factors, but there are no systematic studies on Brazilian population until now. The knowledge of these factors will lead to the elaboration of early diagnostic and preventive strategies taking into account that despite remarkable developments in therapy, the socio-economic burden of the disease is likely to increase worldwide as the population ages. Purpose: To identify risk factors associated with the onset and progression of age-related macular degeneration in a Brazilian population aiming the assessment of possible preventive measures based in the profile of these patients. Methods: A cross-sectional study with control group was performed in 236 participants aged 50 years or older including 141 affected individuals and 95 controls without disease, all current patients from the Department of Ophthalmology-Otorhinolaryngology of Clinical Hospital, Faculty of Medical Sciences-Unicamp. Ocular examinations were performed including color stereoscopic fundus photographs and data including demographic factors, ocular and medical history, family history of AMD, lifestyle, smoking and drinking habits was obtained by questionnaire from all participants. Results: Of the 141 AMD cases, 99 (71%) had late AMD in at least one eye (57% neovascular AMD and 13% geographic atrophy) and 42 (30%) had early AMD. The visual acuity of the AMD patients (mean of 20/200) was substantially lower than controls (mean of 20/40). More than 50% of AMD cases had visual impairment among (RR 9.89; 95%CI: 3.79-25.81). Age (RR 1.51; 95% CI: 0.88-2.58), positive family history of AMD (RR 6.58; 95% CI: 1.94-22.31); presence of cardiovascular disease (CVD) (RR 2.39; 95% CI: 1.08-5.28), low physical activity level (RR 1.39; 95% CI: 0.82-2.37) and high serum cholesterol (RR, 1.49; 95% CI: 0.84-2.65) were associated to increased risk for AMD. There was no significant association with sex, IMC, cataract/cataract surgery, skin color, iris color, sunlight exposure, antioxidants intake, history of hypertension, diabetes, smoking status and alcohol consumption between the groups of AMD patients and controls. Comparing data between affected individuals, there was a significant association with history of CVD and incidence of late AMD (RR 2.29; 95% CI 0.81-6.44). There were higher levels of serum cholesterol among subjects with early AMD than those with late AMD (RR 1.67; 95% CI: 1.09-4.80). A correlation of 0.351 was obtained in discriminant analysis (stepwise), where factors such as family history, age, low physical activity and high serum cholesterol were considered. Conclusions: This findings show that the main risk factors associated to AMD in this population are: age, family history, cardiovascular disease (CVD), high level of cholesterol and low physical activity. Among these factors, patients with history of CVD were associated with increased risk to advanced AMD and higher levels of plasma cholesterol were found among individuals with early AMD. As CVD and late AMD apparently share multiple risk factors, final recommendation was made that both conditions could be prevented jointly through programmes of health promotion for the elderly. The targets include combat of hypertension, diabetes, obesity (high BMI), smoking, alcoholism and bad eating habits, although in isolation were not statistically significant in this study. The role of heredity in this condition was also highlighted as well as the prospect of family members of affected individuals to be informed about risk of recurrence and preventive measures / Doutorado / Oftalmologia / Doutor em Ciências Médicas

Les rétinopathies ischémiques et la forme humide de la dégénérescence maculaire liée à l’âge (DMLA) sont la principale cause de malvoyance respectivement chez les personnes en âge de travailler et les personnes agées. Les néovascularisations choroïdiennes (NVC) et rétiniennes et l’œdème maculaire associés à ces pathologies sont traités à l’aide de biomolécules qui ciblent uniquement la voie de signalisation des VEGF. Le développement de thérapies indépendantes de cette voie permettrait d’offrir aux patients résistants aux anti-VEGF une alternative thérapeutique pour préserver leur vision. Les intégrines αvβ3 et αvβ5, impliquées dans la néovascularisation oculaire, apparaissent ainsi comme une cible alternative intéressante. La Lébécetine (LCT), une lectine de type-C, de 30 kDa et de structure hétérodimèrique issue de venin de serpent Macrovipera lebetina interagit spécifiquement avec les intégrines α5β1 et αvβ3, αvβ5. La LCT a une activité anti-angiogénique in vitro sur des cellules endothéliales microvasculaire du cerveau humain (HBMEC) et in vivo sur le modèle de la membrane chorioallantoïde du poulet (CAM). Afin d’étudier son effet sur la néovascularisation oculaire, nous avons eu recours aux modèles d’angiogenèse ex vivo utilisant des explants aortique ou choroïdien cultivés en présence de LCT, puis son effet a été évalué in vivo dans un modèle de NVC chez la souris et également sur la néovascularisation rétinienne dans le modèle de rétinopathie induite par l’oxygène (RIO). Nos données démontrent qu’une injection unique de LCT est capable de réduire la NVC et rétinienne dans ces modèles sans affecter les vaisseaux quiescents matures indiquant un bon profil d’innocuité. / Ischemic retinopathies and the wet form of age-related macular degeneration (AMD) are characterized by devastating angiogenesis responsible for the majority of irreversible blindness. Current therapies include use of anti-VEGF agents to reduce choroidal neovascularization and edema. These treatments are effective in most cases, but spontaneous or acquired resistance to anti-VEGF highlight a need for additional alternative therapies. In recent years, pharmacological inhibition of αvβ3 and αvβ5, which regulate endothelial cell proliferation and stabilization, have emerged as new therapeutic tools for the treatment of these diseases. Lebecetin (LCT), a 30-kDa heterodimeric C-type lectin that is isolated from Macrovipera lebetina venom, interacts with α5β1 and αv-containing integrins (αvβ3, αvβ5). We previously showed that LCT has an anti-angiogenic effect in vitro on human brain microvascular endothelial cells (HBMEC) and in vivo in a chick chorioallontoic membrane assay (CAM). To evaluate the inhibitory effect of LCT on ocular angiogenesis, we cultured aortic and choroidal explants in the presence of LCT and analyzed the effect of LCT on choroidal neovascularization in the mouse CNV model and on retinal neovascularization in the oxygen induced retinopathy (OIR) model. Our data demonstrated that a single injection of LCT efficiently reduced choroidal and retinal neovascularization in these models with no significant effect on mature blood vessels predicting a good safety profile.

Ansamling av amyloid beta (Aβ) i de extracellulära miljöerna är associerad till många svåra sjukdomar som Alzheimers och ålders-relaterad makuladegeneration (AMD). Amyloider karaktäriseras av att de är olösliga, toxiska mot neuron och orsakar därför svår skada. AMD är den ledande orsaken till blindhet och irreversibelt förlorande av skarp syn då Aβ manifesterar i makula. I AMD orsakar Aβ inflammatorisk aktivitet där det retinala pigmentepitelet bryts ned och ljuskänsliga fotoreceptorer dör genom apoptos. Idag lever ca 150 miljoner människor med AMD där mänga har svårt att utföra vardagliga uppgifter till följd av förlust av skarp syn. Idag är Kongo röd en av de vanligaste metoderna för att visualisera amyloider in vitro. Den patogenes som orsakas av amyloider kan analyseras med immunofluorescens och immunohistokemi. Syftet med studien var att undersöka förekomst av amyloider i samband med celldöd i näthinna från gris, undersöka den patogenes som amyloider orsakar med immunofluorescens och immunohistokemi, samt undersöka om det finns korrelation mellan amyloider och celldöd. Resultatet visade att amyloider var förekommande i näthinnan och hade orsakat celldöd och ansamling av aggresomer. Amyloider och den patologi som orsakats kunde visualiseras i det yttre lagret av näthinnan. / Deposition of amyloid beta (Aβ) in the extracellular environment are associated to some severe diseases, like Alzheimer’s disease and age-related macular degeneration (AMD). Amyloids are characterized by insolubility, toxicity towards neuron and are there-for damaging to tissues. AMD is the primary cause of blindness and irreversible loss of central vision through manifestation of Aβ in the macula. In AMD, Aβ drives an inflammatory action that degenerates the retinal pigment epithelium and cause atrophy of photoreceptors. Today ~150 million people live with AMD where many find difficulties performing everyday tasks due to loss of sharp vision. Congo red is a gold standard for visualizing amyloids in vitro and the pathogenesis caused by amyloids can be analyzed by immunofluorescence and immunohistochemistry. The purpose of this study was to show the presence of amyloids relating to cell death in pig retina, show the pathogenesis caused by amyloids by using immunofluorescence and immunohistochemistry, and investigate whether there is correlation between amyloids and cell death. The result showed that amyloids were present in the retina and caused cell death and gathering of aggresomes. Amyloids and the caused pathology could be visualized in the outer layer of the retina.

The purpose of this dissertation was to understand how genetics, socioeconomic status (SES), and lifestyle factors influence the development of age-related macular degeneration (AMD), glaucoma, and diabetic retinopathy in an adult population in Dallas County. Two hundred fifty-three older adults participated in this study as the sample. Crosstabulation and binary logistic regression were utilized to analyze the data. Results indicated a disparity among participants' test scores, visual health status, and perceptions of their visual impairment and highlighted the fact that many seniors are not educated about age-related retinal disorders. Furthermore, variables reaching statistical significance were consistent with the literature included race/ethnicity, age, having a family history of both AMD and diabetes, frequency of eye exams, and level of education. The results not consistent with the literature as affecting visual health included health insurance, access to health care, body weight, and smoking status. Recommendations for future study included applied research focusing on determining risk factors, raising awareness, educating, and providing early detection of these diseases among low to middle income Caucasian, African American, and Hispanic older adults.