The pathogenesis of allergic conjunctivitis.

The clinical presentation of the various forms of allergic conjunctivitis varies greatly from mild symptoms to severe disease with vision-threatening complications. Although an IgE-mediated type-1 hypersensitivity reaction has been demonstrated or postulated in many types of allergic eye disease, the pathophysiology underlying the allergic conjunctivitides is not fully understood. The variety of currently available treatment options underscores the complexity of the chemical reactions associated with mast cell degranulation and mediator release causing the onset of allergic signs and symptoms. Many of these treatments are merely palliative and do not eliminate the complex immune response initiating the symptoms, so there is a recurrence of disease as soon as the therapy is discontinued. Models of allergic eye disease have significantly aided the discovery of new anti-allergic and anti-inflammatory compounds that can be used safely in the eye.