Prevention of cyclosporine A in different methods of administrations on the rejection after penetrating keratoplasty in rabbit eyes / 中华实验眼科杂志

ABSTRACT

Background Cyclosporine A (CsA) is an effective drug to prevent rejection response after penetrating keratoplasty (PKP).Appropriate dosage forms and right administrating route is very important for improving the bioavailability of CsA.Objective This study was to investigate the preventing effect of CsA microspheres via subconjunctive and anterior chamber injection and CsA eye drops on immune rejection after PKP.Methods Sixty eyes of 60 clean adult New Zealand white rabbits served as receipts,and 60 eyes of 30 clean adult pigmented rabbits were used as the donors.The receipts were randomized into the blank control group (only PKP group),subconjunctival CsA injection group,subconjunctival vector injection group,anterior chamber CsA injection group,anterior chamber vector injection group,and 1％ CsA eye drops group.PKP was performed on the all rabbits,and then the CsA microsphere (0.1 ml,12 g/L) or blank microsphere (0.1 ml) were respectively administered in the corresponding groups.The corneal grafts were examined by slit lamp microscope regularly,and rejection index (RI)was calculated based on the corneal opacity,edema and neovascularization.The intraocular pressure (IOP) of operative eyes was measured by Tono-pen tonometer before operation,3 days,1 week,2 weeks,3 weeks,1 month,2 months and 3 months after operation,respectively.Histopathological examination on corneal grafts was performed 1month and 3 months after operation.Results The IOP of all the rabbits lowed after operation,but there was no statistical difference in different time points and various groups (Ftime =29.210,P =0.000; Fgroup =0.254,P =0.938).The grafts of the blank control group,subconjunctival vector injection group and the anterior chamber vector injection group showed varied degrees of corneal opacity and neovascularization 2-3 weeks after operation,and the degree of graft opacity was aggravated obviously in the fourth week,with the RI 8.60±1.52,8.60±0.55 and 8.80±0.84 individually.Neovascularization of the grafts in the subconjunctival CsA injection group,anterior chamber CsA injection group,and 1％ CsA eye drops group was found 3 weeks after operation,and the RI were 4.40±0.89,3.20±0.84 and 3.00±0.71,showing a significantly lower than that of the control groups (P＜0.05).Mild inflammatory response of the grafts was seen in the anterior chamber CsA injection group,but it was lightened over time.The histopathological examination revealed obvious thickening of corneal grafts,neovascularization and infiltration of lots of inflammatory cells in the blank control group,subconjunctival vector injection group and the anterior chamber vector injection group.However,only slight new blood vessels and inflammatory response were seen on the subconjunctival CsA injection group,anterior chamber CsA injection group,and 1％ CsA eye drops group.Conclusions Administration of CsA in different methods can prevent the immune rejection after PKP in rabbit eyes,the effect of giving drugs via anterior chamber injection is better than that via subconjunctive pathyway.