Abstract: Objective  To investigate the prevention effect of cyclosporine A nano-particle eye drop on cornea immune rejection in a rat experimental model. Design Experimental study. Participants Fifty Lewis rats and twenty-five F344 rats. Method Fifty Lewis rats were divided into 5 groups (group A to group E), all of which were received penetrating cornea transplantation in the right eyes. The provider were F344 rats. Group A received vehicle eye drop, group B received ordinary cyclosporine eye drop, group C to E received 0.5%, 1% and 2% cyclosporine A nano-particle eye drop respectively. All the receptor eyes received the eye drops 4 times a day. Cornea were observed with slit lamp and photographs were taken everyday within 14 days after cornea transplantation, and then observed every other day until 28 days. The mean survival time and rejection index (RI) were calculated. The corneas were studied pathologically at day 14th. Main Outcome Measures Cornea survival time, rejection index, pathologically observation of cornea. Results  The mean survival time in group A, B, C, D, E were 8.1±1.37 days, 12.5±4.72 days, 12.11±4.46 days, 13.11±4.65 days and 13.56±3.88 days respectively(F=2.916, P=0.032). The survival time in any of group B, C, D, E is longer compared with group A (all P<0.05). RI of group A to E was 7.3±0.67, 5.5±1.35, 6.11±1.45, 5.22±1.48 and 4.77±1.20, respectively (F=5.782, P=0.001). RI in group B, C, D, E is lower compared with group A(all P<0.05).  No significant difference was found between any of group C, D, E and ordinary cyclosporine eye drop (P=0.297, 0.634, 0.219). But significant difference was found between 2% cyclosporine A nano-particle group and 0.5% group (P=0.03).  Conclusion  Cyclosporine A nano-particle eye drop can effectively prevent cornea rejection after penetrating cornea transplantation. Its effect is similar to ordinary cyclosporine eye drop. The effect of 2% cyclosporine A nano-particle eye drop was better than 0.5% cyclosporine A nano-particle eye drop. (Ophthalmol CHN, 2012, 21: 55-59)

Key words:  penetrating corneal transplantation, immune rejection, Cyclosporine A, nano-particle eye drop