[Effects of mutant kringle 5 eye drops on the survival time of corneal allografts in rat].

OBJECTIVE

To investigate the preventative effect of mutant kringle 5 (mK5) eye drops on corneal allograft rejection.

METHODS

It was a experimental study. The outbred strain F344 and Lewis rats were used as donors and recipients respectively. Sixty Lewis rats were randomly divided into B, C, D and E Group; Group A, F344 rats autograft control; Group B, allograft control (the control groups were given normal sodium only); Group C and D, allograft groups, were treated with 5 mg/L and 10 mg/L mK5 eye drops respectively; Group E, allograft group, was treated with 0.1% dexamethasone eye drops. The eye drops were applied one drop four times per day for two weeks, the occurrence and development of corneal allograft rejection and corneal neovascularization (CNV) was observed every other day by slit-lamp microscope, the grafts were evaluated clinically by means of Holland's scoring system and the area of CNV was calculated. Nine rats per group were killed on the 14th day, and the corneas were taken for histopathological examinations. Analysis of variance was used to analyze the outcomes.

RESULTS

The average graft survival time of Group B, C, D and E was (9.3 +/- 2.1), (21.1 +/- 7.3), (23.5 +/- 10.8) and (28.2 +/- 19.1) d respectively, Compared with Group B, Group C and D had a statistically significant prolongation of survival time (q = 10.24, 13.47; P < 0.05). Though treated with 0.1% dexamethasone eye drops (Group E) prolonged transplant survival time as compared with mK5 eye drops, but the difference was not statistically significant (q = 2.54, 1.49; P > 0.05). The occurrence of CNV in Group A was (3.1 +/- 0.8) d, Group B (2.6 +/- 0.5) d, Group C (6.4 +/- 0.5) d, Group D (7.8 +/- 0.7) d and Group E (5.3 +/- 1.0) d. Significant difference (q = 31.58, 51.21, 19.98; P < 0.05) was found between groups C, D, E and Group A. There were also significant difference between groups C, D, E and Group B (q = 43.87, 67.14, 24.53; P < 0.05). The CNV areas of Group C and Group D were also smaller than Group B (q = 30.76, 62.14; P < 0.05). The results was similar compared with Group E (q = 15.20, 25.64; P < 0.05). Fewer inflammatory cells and CNV were found in the cornea of the groups treated with mK5 eye drops.

CONCLUSION

Topical application of mK5 eye drops can prevent corneal graft rejection and corneal neovascularization in rats.