Topical tacrolimus for the management of acute allergic conjunctivitis in a mouse model

Background Acute allergic conjunctivitis is a constantly challenging condition that often requires steroids for effective management. Alternative treatment options are needed due to the potential side effects of steroids. Tacrolimus has been used for vernal/atopic conjunctivitis. The aim of our study was to investigate the therapeutic effect of topical administration of 0.03 % tacrolimus (eye drops or ointment) in comparison to 0.1 % dexamethasone in a mouse model of acute allergic conjunctivitis. Methods BALB/c mice were sensitized by an intraperitoneal injection of 10 μg/0.2 ml ovalbumin (OVA) absorbed on ALUM (2.0 mg) on days 1 and 8. They were challenged by topical instillation of 2 μl of 15 % OVA (absorbed in 10 % glycerol) twice daily, on days 15–21. Treatment was administered twice daily on days 17–21. Mice were randomly assigned topical treatment groups: Group 1, 0.1 % dexamethasone drops; Group 2, 0.03 % tacrolimus drops; Group 3, 0.03 % tacrolimus ointment; Group 4 PBS drops (control). On day 22 all mice underwent clinical evaluation, blood sampling for IgE levels, and conjunctivas were removed for eosinophil counting. Results IgE and OVA-specific IgE levels were similar among all groups, demonstrating induction of allergic reaction in all mice. Significantly lower clinical scores were found among all treated groups as compared to controls ( P 0.05). Conjunctival eosinophil counts were significantly lower in Group 1 ( P