PubMed · 552016
Problems and difficulties in Keratoprosthetics operations are described and methods of overcoming them discussed.
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G Sommer. 1979. [Problems and developments in keratoprosthetics].. https://pubmed.ncbi.nlm.nih.gov/552016/
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Epithelial cells are key players in the first line of defense offered by the mucosal immune system against invading pathogens. In the present study we sought to determine whether human corneal epithelial cells expressing Toll-like receptors (TLRs) function as pattern-recognition receptors in the innate immune system and, if so, whether these TLRs act as a first line of defense in ocular mucosal immunity. Incubation of human primary corneal epithelial cells and the human corneal epithelial cell line (HCE-T) with peptidoglycan or LPS did not lead to activation, at the level of DNA transcription, of NF-kappaB or the secretion of inflammation-associated molecules such as IL-6, IL-8, and human beta-defensin-2. However, when incubated with IL-1alpha to activate NF-kappaB, the production by these cells of such inflammatory mediators was enhanced. Human corneal epithelial cells were observed to express both TLR2- and TLR4-specific mRNA as well as their corresponding proteins intracellularly, but not at the cell surface. However, even when LPS was artificially introduced into the cytoplasm, it did not lead to the activation of epithelial cells. Taken together, our results demonstrate that the intracellular expression of TLR2 and TLR4 in human corneal epithelial cells fails to elicit innate immune responses and therefore, perhaps purposely, contributes to an immunosilent environment at the ocular mucosal epithelium.
This paper explores the seminal contributions of David Maurice to the field of ophthalmic instrumentation. His development of the specular microscope, the scanning slit optical confocal microscope, and the corneal microfluorometer resulted in advances in our understanding of corneal morphology, physiology, and pathology. The development of the scanning slit, clinical confocal microscope is not a new paradigm or a paradigm shift, but a continuous series of interlinked technical advances from the early work of Vogt to Thaer's development of a clinical confocal microscope. For each instrument both the connection to the prior work of others and the unique advances are discussed and contrasted. This paper develops the connections and parallel developments in the instrument developments of Goldmann, Maurice, Svishchev, Baer, Koester, Masters, and Thaer. The evidence in support of the thesis consists of published papers, patents, personal communication, and study of Goldmann's book collection in Bern. A second theme is that knowledge of physics is a prerequisite for optical instrument development in ophthalmology. David Maurice had a university degree in physics and Hans Goldmann learned physics from his books. The contributions of David Maurice to optical instrumentation follow the major contributions of Goldmann and facilitated and stimulated other scientists who acknowledged their important intellectual debt to David Maurice.
The thickness of the cornea was reported in more than 100-year-old textbooks on physiological optics (Helmholtz, Gullstrand). Physiological interest was revived in the 1950s by David Maurice, and over the next 50 years, this 'simple' biological parameter has been studied extensively. Several techniques for its measurement have been described and physiological and clinical significance have been studied. In this review, the different methods and techniques of measurement are briefly presented (optical, ultrasound). While the corneal thickness of many animals are the same over a considerable part of the surface, in the human cornea anterior and posterior curvature are not concentric giving rise to a problem of definition. Based on this the precision and accuracy of determining the central corneal thickness are discussed. Changes in corneal thickness reflects changes in function of the boundary layers, in particular the endothelial barrier. The absolute value of thickness is of importance for the estimation of IOP but also in diagnosis of corneal and systemic disorders. Finally it is discussed to what extent the thickness is a biometric parameter of significance, e.g. in the progression of myopia or in the development of retinal detachment.