This research is a single-center prospective, randomized controlled study. Patient were divided into two groups, the control group is phacoemulsification surgery group and the intervention group is phacoemulsification surgery combine intravitreal injection of Ranibizumab group. Eye examination including visual acuity, intraocular pressure(IOP), fundus fluoroscopy, macular optical coherence tomograph（OCT） examination, were taken before cataract surgery. The anterior aqueous humor was extracted before cataract phacoemulsification in the combined operation group, and 0.05 ml of ranibizumab was injected into the vitreous immediately after the operation. The aqueous humor concentrations of vascular endothelial growth factor（VEGF）, interleukin（IL）IL-2, IL-4, and Tumor Necrosis Factor（TNF） were checked by real-time polymerase chain reaction assay（RT-PCR） and ELISA analysis. The Best Corrected Visual Acuity（BCVA）, IOP and fundus lesions changes were observed in the two groups after operation. Diabetic retinopathy capillary non-perfusion zone were evaluated one year after phacoemulsification surgery.
Diabetic retinopathy has been found progress in 20-70% diabetic patient after cataract phacoemulsification surgery. Intravitreal injection of anti-VEGF Ranibizumab is an important treatment for diabetic retinopathy including non-proliferative diabetic retinopathy (NPDR). However, there is no research about phacoemulsification surgery combine Intravitreal injection of Ranibizumab on diabetic retinopathy. The research focus on the effect of phacoemulsification surgery combine intravitreal injection of Ranibizumab on mild non-proliferative diabetic retinopathy and explore the reasons for differences in treatment outcomes.