AIM: To investigate the effects and mechanism of anti-vascular endothelial growth factor(VEGF)assisted pars plana vitrectomy(PPV)in the treatment of proliferative diabetic retinopathy(PDR).

METHODS: A total of 92 patients(92 eyes)with PDR treated by PPV were divided into the simple PPV group(41 patients with 41 affected eyes)and the combined treatment group(51 patients with 51 affected eyes)according to whether the patient underwent intravitreal injection of Ranibizumab(IVR). The combined treatment group was treated with IVR at 5-7d before PPV. The surgical time, times of electrocoagulation, silicone oil filling rate, the incidence of postoperative complications, LogMAR BCVA of affected eyes, levels of VEGF and pigment epithelium derived factor(PEDF)in aqueous humor and vitreous body were compared between the two groups.

RESULTS: The surgical time was shorter, the times of electrocoagulation was less, the silicone oil filling rate and the incidence rates of iatrogenic retinal hole and vitreous body hematocele were lower in the combined treatment group than in the simple PPV group(P<0.05). Levels of VEGF and PEDF in aqueous humor and vitreous body of the combined treatment group during PPV were lower than those in the simple PPV group(P<0.05). The LogMAR BCVA of the affected eyes of the combined treatment group in 3mo after surgery was better than that of the simple PPV group(P<0.05).

CONCLUSION: IVR combined with PPV can reduce the perioperative levels of VEGF and PEDF, reduce the times of electrocoagulation and the incidence of iatrogenic retinal hole and vitreous body hematocele, and improve the visual acuity of patients with PDR.