Atopic keratokonjungtivitis is observed in approximately 15 to 40% of patients with atopic dermatitis. Whereas allergic conjunctivitis is usually a self-limiting process,  atopic keratoconjunctivitis is chronic and can potentially cause loss of vision. Immunological and immunohistochemical studies reveal mast cells, IgE antibody, eosinophils, and other inflammatory cells in similar quantities to those found in allergic conjunctivitis. The finding of lymphocyte involvement explains the chronic nature of the disease as well as the threat to sight.  Additional findings include antibodies to ICAM-1 and HLA-DR throughout the ocular epithjelium, suggesting increased antigen presentation. Also, increased level of RANTES, an eosinophil homeostasis chemokine, are observed in immunochemical studies of the epithelium. Fibroblast numbers are increased in the connective tissue with an increased level of collagen compared with normal tissue. This infiltration is likely critical to the sight-threathening nature of the disease.