8/29/03 Conjunctival allergen challenge in the investigation of ocular allergySummaryAllergic reactions occur commonly in and around the eyes. At least 90% of these reactions are seasonal and/or perennial allergic conjunctivitis. The role of allergen challenges in such reactions was reviewed by Abelson. Such challenges lead to an initial mast cell activation with release of several mediators. The local levels of histamine are reduced by locally released histamine which catabolyzes histamine. This reaction may be followed in some cases by a later appearing inflammatory reaction analogous to the late phase reactions in the nose and lower airways. Challenges may occur by direct application of allergens/control substances to the conjunctival sac or an environmental challenge similar to the "pollen chamber" approach used to investigate mechanisms and medication effects in allergic rhinitis. The effects of a number of systemic and locally applied medications on allergen induced allergic conjunctivitis have been investigated. It has also been found that allergen induced conjunctivitis is sometimes accompanied by typical allergic rhinitis manifestations. Reference Current Allergy and Asthma Reports 2003; 3:363-8 Editor’s Comments The allergic problems in the eye have received less attention than allergic rhinitis and asthma in my opinion despite the morbidity and negative effects on quality of life resultant from such ocular disorders. This discussion is focused mainly on pathophysiologic mechanisms uncovered by allergen challenges in the eyes of sensitive subjects. However, the implications for therapeutic approaches are also discussed.
|
