ObjectiveTo observe the effect of preoperative intravitreal ranibizumab injection (IVR) on the operation duration of vitrectomy and postoperative vision for the treatment of proliferative diabetic retinopathy (PDR). MethodsA prospective study was carried out with the 90 PDR patients (90 eyes) who underwent vitrectomy. The 90 patients(90 eyes)were assigned to the vitrectomy only group(43 eyes) and the IVR combined with vitrectomy group (47 eyes). The IVR was performed 5-13 days prior to vitrectomy in the IVR combined with vitrectomy group. There were 15 eyes with fibrous proliferation PDR (FPDR), 16 eyes with advanced PDR (APDR) without involving the macular and 16 eyes with APDR involving the macular in the vitrectomy only group. There were 14 eyes with FPDR, 15 eyes with APDR without involving the macular and 14 eyes with APDR involving the macular patients in the IVR combined with vitrectomy group. All the eyes in the two groups were regularly operated by the same doctor to complete the vitrectomy. The start and end time of vitrectomy were recorded. The average follow-up time was 10 months. The changes of best corrected visual acuity (BCVA) before and 1, 3 and 6 months after surgery were compared between the two groups. ResultsThe duration of operation of the FPDR type (t=-8.300) and the APDR involving the macular type (t=-2.418) in the IVR combined with vitrectomy group was shorter than vitrectomy only group (P < 0.05). The comparison of duration of operation of the APDR without involving the macular type in the two groups has no statistically significant difference (t=-1.685, P > 0.05). At 1 month after surgery, the comparison of BCVA of the IVR combined vitrectomy group and the vitrectomy only group in APDR involving the macular type has no statistically significant difference (t=0.126, P > 0.05). At 3, 6 months after surgery, the BCVA of the IVR combined vitrectomy group in APDR involving the macular type was significantly better than the BCVA of the vitrectomy only group (t=8.014, 7.808; P < 0.05). At 1, 3, and 6 months after surgery, the BCVA of the IVR combined vitrectomy group in FPDR type (t=3.809, 1.831, 0.600) and APDR without involving the macular type (t=0.003, 1.092, 3.931) compared with pre-treatment, the difference were not statistically significant (P > 0.05); the BCVA in APDR without involving the macular type compared with pre-treatment, the difference was distinctly statistically significant (t=2.940, 4.162, 6.446; P < 0.05); the BCVA in APDR involving the macular type (t=0.953, 1.682, 1.835) compared with pre-treatment, the difference were not statistically significant (P > 0.05). ConclusionPreoperative IVR of PDR can shorten the operation duration and improve the BCVA of APDR involving the macular type.
ObjectiveTo analyze the concentrations of vascular endothelial growth factor (VEGF) and pigment epithelium-derived factor (PEDF) in aqueous humor of patients with proliferative diabetic retinopathy (PDR) before and after intravitreal injection of ranibizumab. MethodsTwenty-five eyes of 20 PDR patients were collected as the PDR group. Twenty-five eyes of 21 senile cataract patients were collected as the control group. There were no statistical significance in gender (χ2=0.223), age (Z=-1.555) and intraocular pressure (Z=-0.225) between the two groups (P > 0.05). Samples of aqueous humor (0.1 ml) were collected just before and 7 days after the injection of ranibizumab in PDR group. Samples of aqueous (0.1 ml) humor were collected just before cataract surgery in control group. The concentrations of VEGF and PEDF in the aqueous humor were measured by enzyme-linked immunosorbent assay. ResultsThe VEGF and PEDF concentration in the aqueous humor were reduced significantly after intravitreal injection of ranibizumab in PDR group (Z=-4.072, -4.319; P < 0.05). The concentrations of VEGF and PEDF in the aqueous humor before intravitreal injection of ranibizumab in PDR group were significantly higher than the control group (Z=-5.228, 4.706; P < 0.05). The VEGF concentration in the aqueous humor after intravitreal injection of ranibizumab in PDR group were similar to control group (Z=-1.557, P > 0.05). However, the concentration of PEDF in the aqueous humor after intravitreal injection of ranibizumab in PDR group still higher than control group (Z=-2.475, P < 0.05). The ratio of VEGF/PEDF before and after intravitreal injection of ranibizumab was statistically different (Z=-2.058, P < 0.05), but was the same between PDR group and control group (Z=-0.456, -0.844; P > 0.05). The aqueous humor concentrations of VEGF and PEDF were not significantly correlated with each other, neither in PDR group (r=-0.195, -0.174; P > 0.05) nor in control group (r=-0.286, P > 0.05). ConclusionsAqueous humor concentrations of VEGF and PEDF are significantly elevated in eyes with PDR. Intravitreal injection of ranibizumab significantly decreased the VEGF and PEDF in the aqueous humor after 7 days.