Abstract
Purpose:
Corneal neovascularization is a distinctive sign of immune privilege crash of cornea, which is the main incentive to induce the graft rejection after corneal transplantation. To avoid the graft rejection after corneal transplantation of alkali burned cornea, conbercept eye drop was used to prevent the graft rejection following corneal transplantation.
Methods:
The cornea of New Zealand rabbits was burned by placing a Whatman filter paper (8.00 mm in diameter) soaked in 1 N NaOH onto the cornea for 60 seconds followed by washing with PBS for 60 seconds and allowed the injured cornea to heal for 20 days prior to corneal transplantation using a donor cornea collected from Angola rabbit. After surgery, conbercept eye drop was applied to prevent the immune graft rejection and FK-506 eye drop was used as the control. Immunostaining was employed to label the neovascular vessels, inflammatory cells, and lymphatic vessels with the antibody of anti-CD31, vEGF, CD45, CD11b, lyve1, etc.
Results:
After corneal alkali burn, central cornea changed to be cloudy and central corneal epithelium was broken; 2 weeks later, blood vessels proliferated to central cornea from limbus. Following corneal transplantation and application of eye drops, corneal blood vessels were significantly suppressed by treatment of conbercept eye drop and cornea was kept to be transparent; however, the corneas treated by FK-506 eye drop were vascularized and only 3 in 10 corneas were transparent 10 weeks after the treatment. Histology revealed that very few inflammatory cells were found in the corneas treated by conbercept eye drop in comparison with that of FK-506 eye drop at 10 week after corneal transplantation. Moreover, the expression of CD31 and vEGF was significantly reduced in the cornea treated with conbercept eye drop, which revealed by Western blot.
Conclusions:
Application of conbercept eye drop may be a valuable treatment to prevent corneal graft rejection through the suppression of corneal neovascularization.