The management of allergic eye diseases in primary eye care

Allergy is an over-reaction of the body's immune system to innocuous foreign substances or allergens that the body perceives as a potential threat or undesirable. It is estimated to affect approximately 20% of the population. Of this subset at least 20% suffer from ocular allergy. It has a significant impact on the quality of life of the individual. Allergic diseases are those conditions in which an antibody- and/or T-cell mediated mechanisms are involved. Allergic eye diseases are characterized by IgE-mast cell mediated, as seen in allergic conjunctivitis; chronic mast cell activation and eosinophil/T-lymphocyte-mediated response, as seen in giant papillary conjunctivitis, vernal keratoconjunctivitis and atopic keratoconjunctivitis; or a T-lymphocyte-mediated response in contact ocular allergy. The management of allergic eye disease is aimed at preventing the release of mediators of allergy, controlling the allergic inflammatory cascade and preventing ocular surface damage secondary to the allergic response. In the management of ocular allergic disease, the clinician is advised to recommend non-pharmacologic and pharmacologic therapeutic regimens that address the acute presentation of ocular allergy and provide prophylaxis aimed at providing long-term maintenance therapy. This approach to the management of allergic eye diseases aims to minimize the impact of the allergic reaction on the individual's quality of life. To achieve success in the management of allergic eye diseases, the clinician requires a considerable understanding of the pathophysiology, clinical features and differential diagnosis of the different types of ocular allergy, as well as an adequate knowledge of their pharmacotherapy.