BALB/c mice that had been actively sensitized with ovalbumin were challenged with ovalbumin on days 10-14 after initial sensitization. Cyclosporin A (0. 1%) or betamethasone (0. 1%) eye drops were instilled 1, 4, and 7 hours after each challenge. Ocular tissue was harvested for histological evaluation 24 hours after the last challenge, and conjunctival tissue was collected for the measurement of collagen content and quantitative PCR 8 hours after the last challenge.