Eine lokale Aktivierung des Komplementsystems im RPE ist ein pathogener Faktor der AMD. Neben der Wirkung von angiogenen Faktoren wie VEGF könnte eine Aktivierung des Blutgerinnungssystems im RPE dazu beitragen, dass sich aus einer trockenen eine feuchte AMD entwickelt. Dies könnte auf mehreren Ebenen geschehen: Gerinnungsfaktoren könnten die Expression der Komplementfaktoren und der angiogenen Faktoren regulieren sowie Wirkungen auf die Proliferation und Migration der RPE-Zellen besitzen. Eine Stimulierung der Proliferation und Migration der RPE-Zellen trägt zur Ausbildung von CNV-Membranen bei. Es ist aber bis jetzt nichts darüber bekannt, ob RPE-Zellen Faktoren des Blutgerinnungssystems exprimieren und ob z.B. Thrombin (als zentrale Protease des Blutgerinnungssystems) die Genexpression von Komplementfaktoren und von VEGF im RPE beeinflusst. Die Ziele der vorliegenden Dissertation waren daher: ● Nachweis der mRNA-Expression von Blutgerinnungs- und Komplementfaktoren im RPE; ● Nachweis der Wirkung von Thrombin auf die Expression von VEGF und von Komplementfaktoren, sowie auf die Proliferation und Migration der RPE-Zellen; und ● Nachweis der Wirkung der Komplementfaktoren C5a und C9 auf die Sekretion von VEGF und die Proliferation und Migration der RPE-Zellen.

Age-related macular degeneration (AMD) is a major cause of blindness in adults. Abnormal growth of blood vessels in the eye during the course of AMD causes damage to the retina, resulting in irreversible blindness. The goal of this research was to determine whether physical pressure on retinal cells can contribute to the increased blood vessel formation. To replicate the tears in the cell layers, a micropatterning method was used as a means of detaching cells from each other. Two new devices were also developed to mimic slow and fast increases in mechanical pressure on cell layers of the eye. After detaching cells from each other and adding mechanical stress to cells, the levels of angiogenic proteins secreted by retinal cells were measured. The results showed that both cell-cell detachment and mechanical stress can increase the secretion of angiogenic proteins. After adding mechanical stress, we also added the secreted proteins to blood vessel cells and observed an increase in blood vessel formation, indicating that mechanical stress can independently induce angiogenesis. These results suggest that physical stimuli in the eye can contribute to the aberrant blood vessel formation in AMD.

Indiana University-Purdue University Indianapolis (IUPUI) / The thesis includes two application studies of computational fluid dynamics. The first is new and efficient drug delivery to the posterior part of the eye, a growing health necessity worldwide. Current treatment of eye diseases, such as age-related macular degeneration (AMD), relies on repeated intravitreal injections of drug-containing solutions. Such a drug delivery has significant cant drawbacks, including short drug life, vital medical service, and high medical costs. In this study, we explore a new approach of controlled drug delivery by introducing unique porous implants. Computational modeling contains physiological and anatomical traits. We simulate the IgG1 Fab drug delivery to the posterior eye to evaluate the effectiveness of the porous implants to control the drug delivery. The computational model was validated by established computation results from independent studies and experimental data. Overall, the results indicate that therapeutic drug levels in the posterior eye are sustained for eight weeks, similar to those performed with intravitreal injection of the same drug. We evaluate the effects of the porous implant on the time evaluation of the drug concentrations in the sclera, choroid, and retina layers of the eye. Subsequent simulations were carried out with varying porosity values of a porous episcleral implant. Our computational results reveal that the time evolution of drug concentration is distinctively correlated to drug source location and pore size. The response of this porous implant for controlled drug delivery applications was examined. A correlation between porosity and fluid properties for the porous implants was revealed in this study. The second application lays in the computational modeling of the oscillating

Final publication is available at http://www.sciencedirect.com/science/article/pii/S0002939414000488 / 京都大学 / 0048 / 新制・課程博士 / 博士(医学) / 甲第19586号 / 医博第4093号 / 新制||医||1014(附属図書館) / 32622 / 京都大学大学院医学研究科医学専攻 / (主査)教授 大森 孝一, 教授 宮本 享, 教授 横出 正之 / 学位規則第4条第1項該当 / Doctor of Medical Science / Kyoto University / DFAM

京都大学 / 0048 / 新制・課程博士 / 博士(医学) / 甲第20975号 / 医博第4321号 / 新制||医||1026(附属図書館) / 京都大学大学院医学研究科医学専攻 / (主査)教授 川上 浩司, 教授 鈴木 茂彦, 教授 開 祐司 / 学位規則第4条第1項該当 / Doctor of Medical Science / Kyoto University / DFAM

京都大学 / 0048 / 新制・課程博士 / 博士(医学) / 甲第20994号 / 医博第4340号 / 新制||医||1027(附属図書館) / 京都大学大学院医学研究科医学専攻 / (主査)教授 鈴木 茂彦, 教授 伊佐 正, 教授 大森 孝一 / 学位規則第4条第1項該当 / Doctor of Medical Science / Kyoto University / DFAM

Despite being the most prevalent presentation of Age-Related Macular Degeneration (AMD), dry AMD (dAMD) lacks a therapeutic treatment. Retinal pigment epithelium (RPE) dysfunction preceding the onset of dAMD has inspired interest in regenerative medicine approaches seeking to replenish the RPE and preserve visual acuity. Cell delivery to the subretinal space however has been met with challenges surrounding ease of access and invasive surgical implantation. Two-dimensional scaffolds have made use of natural and polymeric materials to act as carriers for RPE cells and various progenitor lines. These substrates mitigate issues surrounding the handling of delicate cell sheets harvested for transplant. As well, they are often successful in preserving RPE phenotype, supporting growth, and can be fine tuned to possess morphologies comparable to native extracellular matrix (ECM). Despite aiming to act as replacement Bruch’s membrane on which RPE resides, two-dimensional substrates are often notably bulky and require traumatic surgery for implantation. As a result, the use of injectable methods of cell delivery has gained appeal. Bolus injections, despite improved methods of administration, are correlated with issues of inadequate cell localization. In response, three-dimensional hydrogel carriers for retinal applications aim to encapsulate cells, allowing for better cell distribution as these materials spread throughout the subretinal space. Increased viscosity of hydrogels as compared to saline injections, is hypothesized to improve cell loss and reduce aggregation. Of particular interest are in situ gelling systems, which undergo physical changes upon injection. Gelation upon delivery works to further assist in maintaining the cells within their target site. Purity and reproducibility concerns associated with the use of natural materials in the development of hydrogel cell carriers, have inspired the use of synthetic thermoresponsive poly-N-isopropylacrylamide (pNIPAAm). pNIPAAm undergoes a liquid to gel transition at a lower critical solution temperature (LCST) of 32°C. Copolymerization with various hydrophobic and hydrophilic groups can be used to adjust gel properties such as increasing or decreasing LCST, allowing for degradation, and improving water retention. In the work described herein, two NIPAAm-based thermoresponsive hydrogels intended for use as subretinal cell carriers are proposed. / Thesis / Master of Applied Science (MASc)

This thesis discusses pyridinium bisretinoid compounds (PBRs), which were prepared for two purposes: 1) to use them as standards for detection of novel fluorophores in human RPE cells, which may be involved in age-related macular degeneration (AMD), and 2) to use them in the development of a targeted and triggered drug delivery system for cancer therapy. We prepared a selection of PBRs using a one-pot biomimetic method; synthesis, mechanisms for formation, and characterization of these compounds is described. We also explored the photoreactivity of three novel PBR compounds and found that these PBRs form oxidation products under blue-light irradiation. The photoinduced cytotoxity of A2P and A2EE was examined in HL-60 cells. Results from this work suggest that the PBRs presented have the potential to be involved in AMD and to be developed into a targeted and triggered drug delivery system for cancer therapy.

yes / Purpose: To demonstrate methods that enable visual field sensitivities to be compared with normative data without restriction to a fixed test pattern. Methods: Healthy participants (n = 60, age 19–50) undertook microperimetry (MAIA-2) using 237 spatially dense locations up to 13° eccentricity. Surfaces were fit to the mean, variance, and 5th percentile sensitivities. Goodness-of-fit was assessed by refitting the surfaces 1000 times to the dataset and comparing estimated and measured sensitivities at 50 randomly excluded locations. A leave-one-out method was used to compare individual data with the 5th percentile surface. We also considered cases with unknown fovea location by adding error sampled from the distribution of relative fovea–optic disc positions to the test locations and comparing shifted data to the fixed surface. Results: Root mean square (RMS) difference between estimated and measured sensitivities were less than 0.5 dB and less than 1.0 dB for the mean and 5th percentile surfaces, respectively. Root mean square differences were greater for the variance surface, median 1.4 dB, range 0.8 to 2.7 dB. Across all participants 3.9% (interquartile range, 1.8–8.9%) of sensitivities fell beneath the 5th percentile surface, close to the expected 5%. Positional error added to the test grid altered the number of locations falling beneath the 5th percentile surface by less than 1.3% in 95% of participants. Conclusions: Spatial interpolation of normative data enables comparison of sensitivity measurements from varied visual field locations. Conventional indices and probability maps familiar from standard automated perimetry can be produced. These methods may enhance the clinical use of microperimetry, especially in cases of nonfoveal fixation.

Yes / Fundus-controlled perimetry (FCP, also called 'microperimetry') allows for spatially-resolved mapping of visual sensitivity and measurement of fixation stability, both in clinical practice as well as research. The accurate spatial characterization of visual function enabled by FCP can provide insightful information about disease severity and progression not reflected by best-corrected visual acuity in a large range of disorders. This is especially important for monitoring of retinal diseases that initially spare the central retina in earlier disease stages. Improved intra- and inter-session retest-variability through fundus-tracking and precise point-wise follow-up examinations even in patients with unstable fixation represent key advantages of these technique. The design of disease-specific test patterns and protocols reduces the burden of extensive and time-consuming FCP testing, permitting a more meaningful and focused application. Recent developments also allow for photoreceptor-specific testing through implementation of dark-adapted chromatic and photopic testing. A detailed understanding of the variety of available devices and test settings is a key prerequisite for the design and optimization of FCP protocols in future natural history studies and clinical trials. Accordingly, this review describes the theoretical and technical background of FCP, its prior application in clinical and research settings, data that qualify the application of FCP as an outcome measure in clinical trials as well as ongoing and future developments.