The immunology of the eye and its systemic interactions

Advances in immunology have provided us with new insights about the ocular inflammatory response. Still, the etiology and pathophysiology of many uveitides remain unclear. Factors such as the blood-ocular barrier, sequestration of retinal antigens, local immunomodulators in the aqueous humor, and anterior chamber-associated immune deviation (ACAID) interact and render the eye an immunologically "privileged" site. On the other hand, human leukocyte antigen complex (HLA) interactions, the immunopathology of hypersensitivity reactions, T-cell mediated disease, and autoimmunity are associated pathogenic mechanisms of immune-related ocular disease. In this paper, we review some of the immunologic characteristics of the eye and their relationship to intraocular inflammation. Clinocopathologic correlations are presented. Also, perspectives of current and future research, as well as diagnostic and treatment strategies, are discussed.