Animal models of ocular allergy and their clinical correlations.

Ocular allergic diseases represent a wide spectrum of disorders, from the acute self-limited, mild form of seasonal allergic conjunctivitis to the chronic, severe, sight-threatening atopic keratoconjunctivitis. The least problematic forms are the most prevalent, and several animal models have contributed to elucidate their etiopathogenetic mechanisms and have served to test numerous anti-allergic compounds. The most severe and chronic, although less prevalent, ocular allergic problems have not benefited from a similar advance, with the subsequent lack of full understanding and a limited therapeutic armamentarium. Research in this field is currently concentrating efforts in developing more protracted models of ocular allergic inflammation involving the cornea and mimicking more closely the human disease caused by chronic ocular allergy. Most recent experimental models are demonstrating that inhibiting Th2 cells and their secreted cytokines might be one important therapeutic target for inhibiting chronic allergic inflammation in the ocular surface.