To observe the effectiveness and safety of topical 0.1% tacrolimus(FK506) as immunosuppressant in high-risk penetrating corneal transplantation to prevent the immune rejection and to compare the outcomes with topical 1% Cyclosporin A (CsA).

The study consists of 49 patients (50 eyes), who were fitted with the high-risk corneal transplantation standard and undergone the penetrating keratoplasty(PKP) or combined operation in Beijing Tongren hospital between March 2015 to September. With the time sequence, the patients were divided into observation group (FK506 group) and the control group (CsA group). The observation group included 9 females and 16 males with an average age of 57.8±14.8. Twenty-four patients were in the control group (25 eyes), including 10 females and 14 males, with an average age of (45.1±16.2). Observation group was treated with topical 0.1% tacrolimus, and the control group treated with topical 1%CsA. Both groups′ treatment combined glucocorticoid as well. Two groups had 1 year follow-up observation. The incidence of rejection was compared by statistical methods of Cox regression. The adverse reactions were graded and compared using Mann-Whitney U test.

After one year, 22 cases of the observation group and 23 cases of the control group were accomplished all observations. The rejection rate was 4.54% in observation group and 27.23% in control group. The difference between the groups was statistically significant (χ²=4.291, P=0.038). Control group had high rejection rate. Besides, there was no severe side effects happened in both groups. After 1 month after surgery, 36.4% of the observation group showed mild corneal edema. The ratio of mild to moderate corneal edema in the control group was 26.1% and 8.7%. Three months after surgery, 4.5% of the observation group showed mild corneal edema, while 13.0% and 13.0% of the control group was found mild to moderate corneal edema. Six months after surgery, 4.5% of the observation group showed moderate corneal edema. The ratio of mild, moderate to severe corneal edema in the control group was 17.4%, 17.4% and 8.7%. The degree of corneal edema in the control group was more serious in three monthes(Z=-2.770, -2.018, -2.941, P<0.05). The differences in both monthes were statistically significant. Mild neovascularization occurred in the 13.6% of observation group. Mild to severe neovascularization occurred in the 13.0%, 4.3%, and 4.3% control groups. The degree of neovascularization in the control group was higher than that in the observation group(Z=-3.221, P=0.001). The differences in both months were statistically significant. Mild to moderate neovascularization occurred in the 18.2% and 9.1% of observation group. Mild to extremely severe neovascularization occurred in the 17.4%, 26.1%, 4.3% and 4.3% control groups. The degree of neovascularization in the control group was higher than that in the observation group(Z=-1.988, P=0.047).The differences in both monthes were statistically significant.

Both 0.1% tacrolimus and 1% cyclosporine A are safe and effective in reducing the rejection after high-risk corneal transplantation. (Chin J Ophthalmol, 2019, 55: 419-427)

High-risk Corneal transplantation; Graft rejection; Immunosuppressive agents; Tacrolimus; Ophthalmic solutions