Allergic and immunologic disorders of the eye Allergic and immunologic disorders of the eye. Part I: Immunology of the eye  Leonard Bielory, MD  Journal of Allergy and Clinical Immunology  Volume 106, Issue 5, Pages 805-816 (November 2000) DOI: 10.1067/mai.2000.111029 Copyright © 2000 Mosby, Inc. Terms and Conditions

Fig. 1 Cross section of the eye. Sagittal cross-sectional view of the human eye revealing the parts commonly involved in immunologic reactions: eyelids—blepharitis and dermatitis; conjunctiva—conjunctivitis; cornea—keratitis; sclera—episcleritis and scleritis; optic nerve—neuritis; iris—iritis; vitreous—vitreitis; choroid—choroiditis; and retina—retinitis. The last four parts involve the inner portion of the eye (the uveal tract) and are classified as forms of uveitis. Journal of Allergy and Clinical Immunology 2000 106, 805-816DOI: (10.1067/mai.2000.111029) Copyright © 2000 Mosby, Inc. Terms and Conditions

Fig. 2 Ocular mast cell distribution. Mast cell distribution in the conjunctiva increases in the more chronic forms of ocular allergy. There is also a noted change in the more chronic forms of ocular allergy from the localization of the mast cell in the substantia propria to the epithelial surface. Journal of Allergy and Clinical Immunology 2000 106, 805-816DOI: (10.1067/mai.2000.111029) Copyright © 2000 Mosby, Inc. Terms and Conditions

Fig. 3 The mast cell appears to play a key role in conjunctival inflammation because it is one of the earliest responders to antigen challenge. Mast cells are known to interact with several other cells that reside in the conjunctiva including fibroblasts and dendritic cells that generate a cascade of various soluble mediators including cytokines, chemokines, and surface receptors. The cellular and mediator-related interactions also play a critical role in both the acute and chronic forms of allergic inflammation at the ocular surface. The soluble mediators and adhesion molecules induce changes in the endothelial/epithelial cells that promote leukocyte adhesion, migration, accumulation, proliferation, and activation. Catabolic mediators, including eosinophilic cationic protein and major basic protein, can induce epithelial damage, whereas fibroblast activation can induce conjunctival scarring. Thus a further understanding of the mast cell interactions at the conjunctival surface would be an effective target for evaluation of potential pharmaceutical interventions in ocular allergic diseases. Journal of Allergy and Clinical Immunology 2000 106, 805-816DOI: (10.1067/mai.2000.111029) Copyright © 2000 Mosby, Inc. Terms and Conditions