Cellular and molecular bases of allergic diseases of the conjunctiva

: The authors review the clinical signs of the five most frequent allergic diseases of the conjunctiva (seasonal allergic conjunctivitis, perennial allergic conjunctivitis, vernal conjunctivitis, atopic conjunctivitis and giant papillary conjunctivitis), and then the immunologic bases of the development of the early-type allergic reaction. In the course of this, they describe the roles played by IgE globulin and the mastocytes in histamine release, and also the possible effects manifested in allergic inflammation in consequence of the metabolic products of arachidonic acid formed in the cell membrane (leukotrienes, lipoxins, prostaglandins and thromboxanes). Following this, they present an account of the process by which the eosinophilic cells that play the main role in the later stages of allergic inflammation emerge from te vascular bed, and the effects of various adhesion molecules. Finally, they discuss a new classification of conjunctivitis (proposed by Bonini), based on the pathomechanisms of the diseases.