Acute inflammation of the eyelid and cornea in Staphylococcus keratitis inthe rabbit

PURPOSE. The inflammatory response during Staphylococcus keratitis was anal yzed biochemically and histologically to determine the source of the neutro phils infiltrating the tear film and cornea. METHODS. Rabbit eyes were swabbed and then examined by slit-lamp microscopy at 0, 5, 10, 15, 20, and 25 hours after intracorneal inoculation with Stap hylococcus aureus. Bacterial colony-forming units were quantified in the co rnea, eyelid, and acute inflammatory exudate. Myeloperoxidase activity of o cular swabs of acute inflammatory exudate, corneal homogenates, and eyelid homogenates was determined. Gross and microscopic examinations of corneas a nd eyelids were performed. RESULTS. The colony-forming units per cornea exceeded 10(7) after 10 hours, whereas no bacteria were cultured from the eyelid until 15 hours postinfec tion. Slit-lamp examination revealed progressive pathology, and the myelope roxidase activities of ocular swabs, corneas, and eyelids increased markedl y by 15 hours postinfection. Corneas showed a wave of neutrophils moving fr om the tear film toward bacteria in the central corneal stroma and early ne utrophil migration from the limbus into the stroma. In the eyelid, neutroph ils migrated from the stromal vessels to the tear film. CONCLUSIONS. Staphylococcus keratitis in the rabbit causes acute inflammati on in the overlying eyelid. Neutrophil of the acute inflammatory exudate in teract with the infected cornea, whereas neutrophils migrating through the cornea from the limbus remained distant from the site of infection.