ULTRASTRUCTURAL PATHOLOGY OF EXPERIMENTAL AUTOIMMUNE UVEITIS - A REVIEW

Experimental autoimmune uveitis (EAU), a disease induced in animals im munised at distant sites with retinal antigens, in conjunction with ap propriate adjuvants, is a well recognised paradigm of various forms of human uveitis since many of the clinical and histopathological manife stations of the human disease can be closely mimicked in this model. E lectron microscopy and other nonultrastructural morphological techniqu es have proven valuable tools in studying the pathology of EAU due to the highly organised and heterogeneous nature of the affected cells an d tissues within the eye, namely the neural retina, retinal pigment ep ithelium and choroid. The role of various resident ocular immune cells including mast cells, dendritic cells, choroidal macrophages and reti nal microglia in the induction and pathogenesis of EAU, is reviewed. I n addition, the role of various effector cells in the inflammatory cel l infiltrate, namely polymorphonuclear leukocytes, T cells and macroph ages, and their interaction with retinal target cells is discussed. Th is review also considers the morphological changes which precede and a ccompany early inflammatory cell infiltration through the blood-ocular barrier which are of critical importance to initiation of the autoimm une process. In many ways EAU represents an ideal model for autoimmune diseases in general and especially for those involving the central ne rvous system. The precise microanatomical arrangement of the eye and i ts distinct blood-tissue barriers have allowed researchers studying EA U to precisely identify the target cells, pathways used by ingressing inflammatory cells and the nature of the effector cells in this diseas e.