Search

Mucosal surfaces are constantly exposed to pathogens and show high immunological activity. In a broad variety of ocular surface disorders inflammation is common, but underlying mechanisms are often not fully understood. However, the main clinical problem is that inflammatory processes are difficult to characterize and quantify due to the impossibility of repeated tissue probing of the delicate ocular surface. Therefore non-invasive optical methods are thought to have the potential for intravital investigation of ocular surface inflammation. This study demonstrates the general potential of two-photon microscopy to non-invasively detect and discriminate key players of inflammation in the ocular surface by using intrinsic fluorescence-based features without the necessity of tissue probing or the use of dyes. The use of wavelength dependent measurements of fluorescence lifetime, in addition to autofluorescence intensity enables a functional differentiation of isolated immune cells in vitro at excitation wavelengths between 710 to 830 nm. Mixed cell cultures and first in vivo results indicate the use of excitation wavelength of 710 to 750 nm for further experiments and future use in patients. [ABSTRACT FROM AUTHOR]

The conjunctiva contains organized lymphoid tissue that consists of intraepithelial lymphocytes, subepithelial lymphoid follicles and adjacent lymphatics and blood vessels. This conjunctiva-associated lymphoid tissue (CALT) is assumed to play a key role in the protection of the ocular surface by initiating and regulating immune responses. The article reviews the current knowledge of CALT in humans and compares its structure and functions with mucosa-associated lymphoid tissues at other mucosal sites. An update is given on CALT animal models and on functional studies on the transepithelial transport of microorganisms and antigenic substances by specialized epithelial cells. The use of two-photon microscopy is reviewed regarding its importance to the understanding of dynamic processes going on within CALT. Copyright © 2009 S. Karger AG, Basel [ABSTRACT FROM AUTHOR]

Meibomian gland dysfunction (MGD) is the leading cause of dry eye disease and loss of ocular surface homeostasis. Increasingly, several observational clinical studies suggest that dyslipidemia (elevated blood cholesterol, triglyceride or lipoprotein levels) can initiate the development of MGD. However, conclusive evidence is lacking, and an experimental approach using a suitable model is necessary to interrogate the relationship between dyslipidemia and MGD. This systematic review discusses current knowledge on the associations between dyslipidemia and MGD. We briefly introduce a diet-induced obesity model where mice develop dyslipidemia, which can serve as a potential tool for investigating the effects of dyslipidemia on the meibomian gland. Finally, the utility of lipidomics to examine the link between dyslipidemia and MGD is considered. [ABSTRACT FROM AUTHOR]