The effect of intravitreal ranibizumab combined with vitrectomy for proliferative diabetic retinopathy

Objective To assess the effect of pars plana vitrectomy (PPV) with or without preoperative intravitreal ranibizumab (IVR) injection for treatment of proliferative diabetic retinopathy (PDR).Methods A prospective study was carried out with consecutive patients with diabetic traction retinal detachment which were underwent PPV at our department from February 2013 to June 2013.Thirty-four patients (37 eyes) were assigned to PPV only (PPV group) or PPV combined with one IVR (0.5mg/0.05ml) injection 1 week prior to surgery (IVR/PPV group).The main outcomes included intraoperative intraocular hemorrhage (measured with erythrocyte count in the fluid retrieved from the vitrectomy cassette using a Neubauer chamber),time of vitrectomy,postvitrectomy vitreous hemorrhage (VH) and visual acuity were assessed.All patients were followed up 6 months.Results A total of 29 patients (31 eyes) fulfilled the study included 12 eyes in the PPV group and 19 eyes in the IVR/PPV group.The mean erythrocyte count in the IVR/PPV group were 79±62.24×106 cells/ml,significantly lowed than 156.54±123.2×106 cells/ml in the PPV group (t =2.315,P =0.028).The mean time of vitrectomy in the IVR/PPV group was 79.47± 15.44 minutes,also significantly lowed than 102.08±22.2 minutes in the PPV groups (t =3.087,P =0.006).The postoperative visual acuity (VA) at 6 months in two groups were all significantly increased than preoperative VA respectively (t =4.92,5.75 P =0.001,0.000).The incidences of postvitrectomy VH (whatever early VH or late VH) and postoperative VA at 6 months had no difference significantly between 2 groups.Conclusions Preoperative intravitreal ranibizumab significantly decrease intraoperative hemorrhage and time of vitrectomy,ease the procedure of operation in complex PDR patients. Key words: Proliferative diabetic retinopathy;  Ranibizumab;  Pars plana vitrectomy