ObjectiveTo detect the effect of adeno-associated-virus induced Kringles5 gene on retinal neovascularization in rats with retinopathy of prematurity (ROP), and to explore the new ways of treatment for ROP.MethodspSNAV-Kringle5-gfp carrier was constructed by subclone and adeno-associated-virus was packed to form rAAV-Kringle5-gfp. ROP model was set up under circumstances of high oxygen in 21 SD rats which were divided into experimental (21 eyes) and control group (21 eyes). Eighteen eyes from each group was used to making the histologic section of retina, and the other 3 eyes in each group was detected by polymerase chain reaction (PCR) and Western blotting. There were 5 rats in the normal control group. AAV-Kringle5-gfp with the dosage of 10 μl and titer of 2.5×1012vg/ml was injected into the eyes in experimental group, while rAAVlacZ with the same dosage and titer of 2.5×1011vg/ml was injected in to the eyes in control group. The expression of target gene in ocular tissues was observed under the fluoroscope. Twelve weeks later, the rats were executed, and the staining of Ⅷ factor related antigens in retinal vascular endothelial cells was performed and number of nucleolus of vascular endothelial cells were counted. ResultsThe plasmid of pSNAV-Kringle5-gfp was correct according to the sequence measurement; the expression of rAAV-Kringle5-gfp was found in vitreous cavity and on retina; the expression of target gene was found on the level of mRNA and protein; the number of nucleolus of vascular endothelial cells on the surface of retina was (19.954 2±3.825 7) in experimental group and (7.335 2±2.731 3) in the control group, which had significant difference between the two groups (P＜0.01）.ConclusionsAdeno-associated-virus induced Kringles5 gene can inhibit the occurrence of retinal neovascularization in patients with ROP.(Chin J Ocul Fundus Dis, 2005,21:288-291)