Optimal use of topical agents for allergic conjunctivitis

In recent years, there has been renewed interest in the topical treatment of allergic conjunctivitis, a disorder that is involved in the common red-eye syndrome. Topical treatment for rapid relief of symptoms is most often preferred by the patient, although physicians are more cautious with the choice of an agent that might worsen symptoms due to contact irritation induced by the substance or its preservative. Theoretical advantages of topical over oral administration include a more rapid onset of action, since the active agent is applied directly to the affected tissue, and a reduced potential for systemic adverse effects. The range of topical agents currently available for the treatment of allergic conjunctivitis varies widely. The 4 primary aims when considering local drug application are: rapid symptomatic relief (particularly applicable to local vasoconstrictors and histamine antagonists);prophylactic therapy (mast cell stabilisers);avoidance of systemic adverse reactions (eye drops containing corticosteroids); anddirect route of administration (specific ocular immunotherapy). In this article we review the underlying pathological mechanisms, present a clinical and diagnostic overview and discuss the available therapeutic options. Finally, we present our treatment strategy, which is based on the nature of the disorder and the patient's expectations. In seasonal or perennial conjunctivitis the combination of decongestants and antihistamines should be first choice for palliative treatment. Mast cell stabilisers should be used as prophylaxis, while immunotherapy can provide a cure. In vernal and atopic keratoconjunctivitis, the decongestant/antihistamine combination can be used for long-term treatment, while courses of topical corticosteroids may prevent flares. Mast cell stabilisers, with lodoxamide in the first place, are used for prophylactic therapy. Surgery may be useful in handling complications. In giant papillary conjunctivitis, hygienic measures regarding contact lenses are mandatory, and sodium cromoglycate (cromolyn sodium) may provide rapid relief. In contact conjunctivitis, removal or avoidance of the sensitiser is most important. Topical use of corticosteroids should be limited to severe cases.