Prevention effect of 5-fluorouracil natural delayed-release microballoons on proliferative vitreoretinopathy

Background: Proliferative vitreoretinopathy (PVR) is a tissue repair prevention and treatment of PVR in clinic. Natural delayed release microballoons are therefore becoming a hot spot for its easy manipulation, large lading dose and long acting duration. Objective: This study was to evaluate the effect of 5-fluorouracil natural delayed release microballoons on the prevention of PVR. Methods: The lymphocytes were collected from clean pigment rabbit to prepare the 8×10⁷/ml cell suspension with complete culture fluid. PVR models were established in 45 healthy pigment rabbits by intravitreal injection of lymphocyte suspension. The animals were randomly divided into 3 groups and 15 rabbits for each. 0.1 ml normal saline, 10 g/L or 20 g/L 5-fluorouracil natural delayed release microballoons were injected into vitreous cavity respectively. PVR was graded on Fastenberg' s method under the slit lamp in 1, 2, 4, 8 weeks. The animals were sacrificed and retinas were obtained for the histopathological and ultrastructural examination in the eighth week after administration of drug. Results: The numbers of eyes with different grades of PVR were significantly different among 3 groups in 1 week, 2, 4, 8 weeks (P<0.05). The eye numbers with PVR was significant less in 20 g/L Fu group than those of 10 g/L Fu group and normal saline group (P<0.05). There was statistical difference in PVR ranking among these 3 groups in 8 weeks after injection of drug (H=46.795, P<0.05). The morphology and ultrastructure of retinas under the light microscope and transmission electron microscope were near normal in all of the three groups. Conclusion: Implantation of 5-fluorouracil natural delayed release microballoons into vitreous cavity is effective and safe in preventing PVR in experimental model, and the therapeutic effect of microballoons with 20 g/L 5-Fu is better.