Anatomy and immunology of the eye

The eye has all the mechanisms necessary for detection and processing (afferent immune reaction) as well as adequate initiation of an (efferent) immune response. Apart from the typical antigen-processing cells, locally present elements (e.g. glial cells and retinal pigment epithelium) can also be involved in the afferent reaction. For the efferent mechanisms a complex regulative system exists, which includes cellular and humoral responses and is essentially determined by surface molecules. In addition, the ocular environment is rich in immunosuppressive molecules that contribute to the regulation of immune cells. The adaptation of the anatomical and biochemical mechanisms for the creation of an immune-privileged microenvironment makes this sense organ unique. The purpose of this article is to highlight the specific features of the eye and to establish a reference to frequent ocular manifestations in rheumatic diseases.