The injection of soluble protein antigens into the normal cornea induces a biphasic allergic reaction. Previous studies suggest that the early phase reaction (characterized by corneal clouding and circumlimbal flare) is mediated by delayed (cellular) hypersensitivity, while the late phase response ("Wessely" ring) results from local antigen-antibody interaction.1-3
Earlier histologic studies of this reaction indicate that the specific cellular elements responding to antigenic stimulation are not found in the cornea, even though the cornea is the site of the gross response. Instead, the immunologically activated cells appear aggregated circumferentially at the limbus.1 Within this cellular infiltrate an orderly transformation has been described. Associated with the early phase response, cells which were predominantly of the lymphoidmononuclear series were noted, while the infiltrate accompanying the late phase response was predominantly plasmocytic in type. In the interval between the two phases, though the sensitized eye appeared clinically normal, cellular forms intermediate