Immune Response to Eye Allergens

Type I hypersensitivity (immediate, IgE-mediated) has been extensively studied in animal models to better understand the immunopathology of allergic conjunctivitis.
Different routes of antigen exposure, including direct sensitization of the conjunctiva, as well as injections of protein antigens into the skin (intradermal) and the vitreous of the eye (intravitreal), resulted in a rise of IgE.
In human studies, specific antigens were applied directly to the conjunctiva. Within minutes, the onset of all symptoms seen in allergic conjunctivitis—redness, itching, swelling, and tearing—were evident. Analysis of tears demonstrated a high concentration of chemicals secreted by white blood cells in defense of the invading antigens.
These chemicals (histamine, leukotrienes, and prostaglandins) are responsible for the inflammatory response typically seen with allergies.


