Deutschsprachige Zusammenfassung Dissertation zur Erlangung des akademischen Grades Dr. med. Titel: Mögliche Korrelation zwischen dem Stadium der altersabhängigen Makuladegeneration und der zentralen Hornhautdicke eingereicht von: Christian Koch angefertigt an der: Klinik und Poliklinik für Augenheilkunde Universität Leipzig betreut von: Professor Dr. med. Peter Wiedemann Klinik und Poliklinik für Augenheilkunde Universität Leipzig Monat und Jahr: Juni 2015 Annahme: Es soll ein statistischer Zusammenhang zwischen der zentralen Hornhautdicke in der Pupillenmitte mit dem nicht exsudativen frühen Stadium der AMD, dem exsudativen späten Stadium der AMD und einer Kontrollgruppe überprüft werden. Methodik: Die erste Studiengruppe stellten 48 Augen von 48 Patienten mit einer Form der frühen AMD dar (Durchschnittsalter 75,4 Jahre, 70,8% der Probanden waren Frauen). Die zweite Studiengruppe bildeten 49 Augen von 49 Patienten mit einer Form der späten AMD (Durchschnittsalter 79,8 Jahre, 59,2% der Probanden waren Frauen). Als Kontrollgruppe wurden 49 Augen von 49 Individuen ohne retinale oder korneale Erkrankungen genutzt (Durchschnittsalter 68,9 Jahre, 59,2% der Probanden waren Frauen). Die Vermessung der Hornhautdicke in Pupillenmitte im Sinne der Hornhautmittendicke erfolgte als Pachymetrie mit der Oculus Pentacam. Ergebnisse: Die durchschnittliche zentrale Hornhautdicke betrug bei der Kontrollgruppe 552,76 μm (SD 36,27 μm), bei der nicht exsudativen Gruppe 552,19 μm (SD 31,27 μm) und bei der exsudativen Gruppe 553,73 μm (SD 33,11 μm). Die Extrempunkte der Kontrollgruppe lagen bei 483 und 640 μm, der Gruppe der nicht exsudativen AMD bei 480 und 617 μm und Minimum und Maximum der exsudativen Gruppe bei 473 und 617 μm. Es gab keine statistisch signifikanten Unterschiede im arithmetischen Mittel der zentralen Hornhautdicke in Pupillenmitte bei der Studiengruppe mit früher AMD im Vergleich mit der Studiengruppe mit später AMD und jeweils im Vergleich zur Kontrollgruppe (P > 0,05). Schlussfolgerung: Die Messwerte der zentralen Hornhautdicke bei Patienten mit früher AMD, später AMD und Kontrollindividuen unterscheiden sich nicht. Die Erhebung der Hornhautmittendicke bietet somit keine Screeningmöglichkeit zur Erkennung einer AMD. / English Abstract Central corneal thickness in patients with AMD Koch, C.; Jochmann, C.; Wiedemann, P. University of Leipzig, Department of Ophthalmology and Eye Hospital, Leipzig, Germany Purpose: To evaluate central corneal thickness in patients with AMD in the early and late phase and a control group. Method: The first study group was made up of 48 eyes of 48 patients with early AMD (mean age 75.4 years, 70.8 % women), the second study group was made up of 49 eyes of 49 patients with late AMD (mean age 79.8 years, 59.2 % women). 49 eyes of 49 individuals without any retinal or corneal damage (mean age 68.9 years, 59.2 % women) were used as control group. The central corneal thickness was measured with the Oculus Pentacam pachymetry. Results: The mean central corneal thickness in early non-exudative AMD group was found to be 552.19 μm (SD 31.27 μm), while the mean central corneal thickness in the late exudative AMD group was measured as 553.73 μm (SD 33.11 μm). The control group had a mean central corneal thickness of 552.76 μm (SD 36.27 μm). There were no statistically significant differences in the mean central corneal thickness in the early non-exudative AMD group in comparison with the late exudative AMD group and each of them compared to the control group (P > 0,05). Conclusion: The central corneal thickness measurements do not differ in patients with early non-exudative AMD, late exudative AMD and control subjects.

Objectif : Nous avons voulu évaluer le risque d’élévation chronique de la pression intraoculaire suite à des injections de ranibizumab dans le traitement de la dégénérescence maculaire liée à l’âge de type néovasculaire. Méthode : Nous avons réalisé une étude rétrospective sur 161 patients ayant reçu des injections de ranibizumab dans un œil seulement. Les critères excluent les patients ayant du glaucome non contrôlé au départ (PIO>21mmHg) et ceux qui ont eu moins de 9 semaines de suivi après l’injection. L’élévation de la PIO est définie comme une augmentation de >5mmHg sur deux visites consécutives. Résultats : Nous n’avons pas déterminé de différence de pourcentage entre les yeux ayant reçus des injections pour lesquels il y a une élévation de la PIO (n=8.5%), comparé au pourcentage de yeux n’ayant pas reçus d’injections pour lesquels il y a une élévation de la PIO (n=9.6%). Cependant, un plus grand nombre d’injections d’anti-VEGF est associé avec une élévation chronique de la PIO (P=0.032). D’autres facteurs de risque de l’élévation chronique de la PIO sont le diabète, une PIO faible au départ, et une PIO maximale plus élevée (P<0.05). Conclusion : Un plus grand nombre d’injections semble augmenter le risque d’élévation de la PIO. Les patients atteints de diabète semblent être plus à risque et nécessiter une étroite surveillance. / Purpose: Conflicting evidence exists about the risk of chronic elevation of intraocular pressure (IOP) after ranibizumab injections for neovascular age-related macular degeneration. The goal of this study is to evaluate this risk. Methods: A retrospective cohort study of 161 people. Inclusion criteria included receiving at least three ranibizumab injections in one eye only and having at least 9 weeks of follow-up. Exclusion criteria included the presence of uncontrolled glaucoma or ocular hypertension at baseline (IOP>=21mmHg). Chronic IOP elevation was defined as an increase >5mmHg of IOP on at least 2 consecutive visits. Results: There was no difference in the percentage of injected eyes that experienced a chronic IOP increase (n=8, 5%) compared to the percentage of uninjected eyes that experienced an IOP increase (n=9, 6%). However, a greater number of anti-VEGF injections was associated with chronic IOP elevation (P=0.032). Other risk factors for chronic IOP elevation included diabetes, a lower baseline IOP, and a higher maximum IOP (P<0.05). Conclusions: A greater number of injections appears to increase the risk of chronic IOP elevation. Also, diabetics appear to be more at risk and may need more careful follow-up or preventive pharmacological treatment.

O atual projeto propôs elaborar e validar uma Tecnologia Educacional sobre Febre Maculosa, com o intuito de oferecer um método inovador de ensino para promover/facilitar a aprendizagem sobre Febre Maculosa. Trata-se de um estudo metodológico, que percorreu as seguintes etapas: análise e diagnóstico; planejamento instrucional, desenho didático, revisão e validação e produção da tecnologia. A análise e diagnóstico foi realizada a partir das experiências vivenciadas em atividades de extensão em educação e saúde para Febre Maculosa no Campus-USP de Ribeirão Preto (2014- 2015). No planejamento instrucional definiu-se que a Tecnologia Educacional sobre Febre Maculosa, seria apresentada em forma de Laboratório Interativo, com estações de aprendizagem. Para a produção do Laboratório contamos com a colaboração de uma equipe multidisciplinar que envolveu pesquisadores enfermeiros, eletricista, marceneiro, artista plástico, alfaiate e designer. O processo de revisão e validação foi dividido em dois momentos: validação de aparência e conteúdo e validação semântica. A validação de aparência e conteúdo foi realizado por 9 (nove) juízes, com experiência na área de biologia e educação; já a validação semântica foi realizada por 8 (oito) alunos do curso de enfermagem e pedagogia. Os resultados da validação de aparência e conteúdo mostraram um IVC superior a 0,8 para a grande maioria das variáveis. Na validação semântica, o Laboratório também teve boa aceitação e compreensão pelos participantes, assim se manteve a mesma organização e conteúdo. Considera-se que a trajetória percorrida para a elaboração do Laboratório Interativo sobre Febre Maculosa confere sustentação acadêmica e científica ao produto construído e ainda contribui para seu potencial pedagógico enquanto um recurso que pode favorecer a aprendizagem significativa, além de contribuir para a transformação das práticas de educação em saúde / The objective of this research was to elaborate and validate an Educational Technology about Rocky Mountain Spotted Fever (RMSF) in order to offer an innovative method of teaching to promote and facilitate learning about RMSF. This methodological study used diagnosis, instructional planning, didactic design, revision, validation, and production of the technology. The analysis and diagnosis were carried out based on an extension activity in education and health related to RMSF at the Campus-USP, Ribeirão Preto (2014-2015). In the instructional planning, we defined that the Educational Technology would be presented in the form of an Interactive Laboratory, with learning stations. The Laboratory production counted with a multidisciplinary team collaboration involving researchers, nurses, electrician, carpenter, plastic artist, tailor and designer. The revision and validation process was divided in appearance and content validation and semantic validation. The appearance and content validation was carried out by 9 (nine) judges, with experience in biology and education areas. The semantic validation was performed by 8 (eight) undergraduates from nursing and pedagogy courses. The results of the appearance and content validation showed a CVI greater than 0.8 to the majority of the variables. In the semantic validation, the Laboratory presented a good acceptance and understanding by the participants, thus maintaining the same organization and content. We considered that the trajectory used for the elaboration of the Interactive Laboratory on RMSF confers academic and scientific support to the constructed product and contributes with its pedagogical potential as a resource that can provide significant learning; furthermore, it contributes with health practices transformation

Age-related macular degeneration (AMD) is one of the leading causes of blindness in the United States in people who are 50 and older. The safety and efficacy of aflibercept for the treatment of late stage neovascular AMD (NAMD) has been demonstrated by clinical trials among several populations; however, it is unclear whether all NAMD patients respond in the same manner as was studied in the clinical trials. The purpose of this study was to examine if populations of patients treated with aflibercept for the treatment of NAMD were significantly different from one another in terms of health characteristics, treatment regimens, and treatment outcomes. The burden of treatment theory was used to guide this study. Data collected from electronic medical records were used to investigate NAMD characteristics 199 patients from 3 private, retinal practices in the United States. Data were analyzed using one-way ANOVA, 2, Spearman's correlation, and point-biserial correlation tests. The results of this study showed the specific retinal practice populations of NAMD patients treated with aflibercept were generally similar with respect to selected health characteristics, treatment regimens, and treatment outcomes. By using the information reported from this research, public health initiatives can be developed that focus on the need for early detection of AMD to capture changes that represent NAMD and move to early treatment for better outcomes. The positive social change that could result from this research is that retinal specialists may gain insight into the use and outcomes of aflibercept treatment.

La Dégénérescence Maculaire Liée à l’Age (DMLA) est la première cause de cécité légale dans les pays industrialisés chez les personnes âgées. L’atrophie géographique – l’une des formes tardives de la DMLA - est caractérisée par la perte de l’épithélium pigmentaire et la dégénérescence des photorécepteurs. Nous groupe a montré précédemment que dans l’atrophie géographique, les phagocytes mononucléés (PMs) s’accumulent dans l’espace sous-rétinien, et induisent la dégénérescence rétinienne via la production d’IL-1β. Dans un premier temps, nous montrons que la présence de PMs sous-rétiniens est associée à la perte des bâtonnets et la dégénérescence des segments de cônes dans la zone de transition de patients atrophiques. Nous montrons ensuite dans différents modèles in vivo et ex vivo que les macrophages récapitulent ces effets, et qu’IL-1β est nécessaire à la perte des segments externes des cônes induite par les PMs. Dans un deuxième temps, nos résultats montrent qu’IL-1β induit indirectement la mort des bâtonnets, en perturbant l’homéostasie rétinienne du glutamate. L’inhibition des récepteurs glutamatergiques pour prévenir l’excitotoxicité du glutamate, ou la supplémentation en cystine favorisant la restauration de la machinerie neuronale antioxydante, permettent de protéger les bâtonnets de la toxicité induite par IL-1β. L’ensemble de nos résultats démontre le rôle joué par IL-1β dans la dégénérescence des segments de cônes et la perte des bâtonnets dans l’inflammation sous-rétinienne. Cette étude permettra la mise au point de thérapies innovantes, afin de lutter contre la forme atrophique de la DMLA, pour laquelle il n’existe actuellement aucun traitement. / In geographic atrophy (GA), one of the late forms of Age-related Macular Degeneration (AMD), an extending atrophic zone forms, characterized by the loss of retinal pigment epithelium and photoreceptor degeneration. Subretinal mononuclear phagocytes (MPs) accumulate in GA, and are associated with IL-1β-dependent retinal degeneration. First, we confirmed that subretinal accumulation of MPs is associated with rod degeneration and cone segment loss in the transitional zone in GA human samples. Using ex vivo and in vivo models, we then demonstrated that MPs-derived IL-1β leads to severe cone segment degeneration. Therefore, inhibiting subretinal MP accumulation or IL-1β might protect the cone segment, and help preserve high acuity daytime vision in conditions characterized by subretinal inflammation. Second, we showed that IL-1β effect on rod degeneration is indirect, and mediated by glutamate. Our results indicate that IL-1β impairs Müller glial cells glutamate recycling, and subsequently leads to the extracellular increase in glutamate content. Inhibiting glutamate receptors to prevent excitotoxicity, or exogenous cystine supplementation to supply antioxidant metabolism, are sufficient to protect rods from IL-1β-induced neurotoxicity. Our results provide new perspectives to treat pathologies associated with subretinal inflammation such as late AMD. Our results collectively demonstrated that MP-derived IL-1β induces cone segment loss, and glutamate homeostasis disruption associated with rod degeneration. This study will help with the development of new therapeutic strategies in dealing with inflammatory retinal pathologies as geographic atrophy.

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.

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.

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.