Progress of neovascularization in rat after corneal transplantation

Objective To observe the progress of neovascularization without intervention in rat after allogenic penetrating keratoplasty.Methods A total of 34 female SD rats(34 eyes) at SPF grade were treated with allogenic penetrating keratoplasty and without intervention after operation. The progress of corneal neovascularization was observed at the 4th,the 7th,the 15th and the 30th day with slit-lamp microscope after operation. The area of corneal neovascularization was calculated with formula C/12×3.14×[r2-(r-I)2],and the percentage of it for the total area of cornea was compared to different times.Results Twenty nine (90.6%) in 32 eyes(except for 1 dead mouse and 1 lost mouse) presented with corneal neovascularization, which distributed around the cornea like hair brush firstly and then extended towards the center. The new vessels intersected and densely covered to reticulate at peak, and then gradually atrophied. The average area of corneal neovascularization was (11.83±3.35)mm2,(18.52±3.96)mm2,(14.38±4.28)mm2 and (6.00±1.84)mm2 at the 4th,the 7th,the 15th and the 30th day after operation, respectively, and (12.68±1.87)mm2 in total. The average ratio for the area of corneal neovascularization on the area of cornea was (30.76±8.72)%,(65.25±12.78)%,(59.35±14.48)% and (36.15±10.90)% at the 4th,the 7th,the 15th and the 30th day after operation, respectively, and 48.67%(6.38%) in total.Conclusion After rat allogenic penetrating keratoplasty without intervention, there is a high incidence of corneal neovascularization, which originates from capillary plexus at limbus corneae. For corneal neovascularization starting immediately after operation, anti-inflammatory therapy should be adopted as soon as possible.