Age-related macular degeneration : a light and electron microscopical study

In the preceding chapters, current knowledge on the normal histology, agerelated changes in the human macula and ARMD is summarized. However, this knowledge is frequently based on one single or only a few observations and it is often mainly descriptive without quantification and/or statistical analysis. Moreover, the results of different investigations are often controversial or even contradictory. Considerable research has been performed in the field of biochemistry, cell biology, histology, clinical evaluation and epidemiology, but several alternatives have remained unexplored or unquantified. The primary aim of this study was to gain more information about the basal laminar deposit, a substance which until now was relatively unknown, but was thought to be associated with the development of age-related macular degeneration. Because experimental animal models in which ARMD can be induced are not known, we chose for a deductive method in which a large series of postmortem human eyes of all ages were studied. Special attention was directed to the morphology, compos1t1on and age-distribution of BLD in the population (chapters 5,6,7,8,9). In addition the histological and morphometrical age-related changes in the maculae (chapter 5). the peripheral retina (chapter 1 0) and the choriocapillaris (chapter 11) of these eyes were quantified and analyzed statistically. We also investigated the histology of human pseudophakic eyes with and without an UV-filter in comparison to normal phakic eyes (chapter 12). For this thesis various techniques have been used such as light microscopical histology, immunohistochemistry, immunofluorescence, transmission electron microscopy, immunoelectron microscopy, electron probe X-ray microanalysis and image analysis. In addition various computerized statistical procedures were applied

Morphologic changes in age-related maculopathy

Age-related maculopathy (ARM) is a degenerative disorder of the central part of the retina with a rising prevalence in patients 50 years of age and older, and comprises different histopathological changes. The morphologic changes in ARM are described and illustrated with light-microscopical, electron microscopical, and fundus pictures. Furthermore, the most important biochemical data are given. The most prominent aging changes in early stages of ARM are drusen and basal laminar deposit (BLD), both extracellular deposits, that are assumed to be important in the development of ARM. Drusen accumulate within Bruch's membrane, whereas BLD is present between Bruch's membrane and the retinal pigment epithelium. Although the histopathologic characteristics of the deposits are well documented, the chemical composition has only been partly resolved. Biochemical analysis of these deposits is necessary to determine the source of the deposits and to find possible ways to avoid or treat them. The late stages of ARM, geographic atrophy, and neovascular (disciform) degeneration, are called age-related macular degeneration (AMD), and result in severe and irreversible visual impairment. Since there is still no adequate therapy for the majority of people disabled by AMD, and because of the aging population resulting in even more patients with this disease, it is necessary to intensify the research on ARM in order to prevent AMD or find a therapy for i