ABSTRACT
BACKGROUND:Studies on the inhibitory mechanism of Avastin for early diabetic retinopathy rats are mostly confined to the vascular endothelial growth factor, while connective tissue growth factor and pigment epithelium-derived factor also play an important role in the disease. OBJECTIVE:To evaluate the changed cytokines of aqueous humor and significance of Avastin intravitreous injection in early diabetic retinopathy rats. METHODS:Rat models of early diabetic retinopathy were established by inducing with streptozotocin for 10 weeks. Avastin (1.25 mg and 2.5 mg) and physiological saline were injected in the vitreous space. RESULTS AND CONCLUSION:Enzyme linked immunosorbent assay results revealed that compared with the physiological saline injection group, mass concentration of vascular endothelial growth factor was reduced, mass concentrations of pigment epithelium-derived factor and connective tissue growth factor was increased in aqueous humor of the two Avastin injection groups (P0.05). Results verified that Avastin intravitreous injection decreased vascular endothelial growth factor levels, decreased pigment epithelium-derived factor mass concentration and increased connective tissue growth factor levels in rat models of early diabetic retinopathy.
ABSTRACT
BACKGROUND:Studies on the inhibitory mechanism of Avastin for proliferative diabetic retinopathy are mostly confined to the vascular endothelial growth factor, while connective tissue growth factor and angiogenesis inhibitor also play an important role in the disease. OBJECTIVE:To evaluate the changes of cytokines in the aqueous undergoing Avastin intravitreous injection or not prior to pars plana vitrectormy in the treatment of proliferative diabetic retinopathy. METHODS:Thirty patients with proliferative diabetic retinopathy (30 eyes) were selected and randomly divided into groups A, B and C, each group containing 10 patients. Group A was treated with single pars plana vitrectormy;and group B and group C had 0.05 mL/1.25 mg and 0.1 mL/1.25 mg Avastin via intravitreous injection at 7 days before pars plana vitrectormy, respectively. Aqueous humor samples were col ected during pars plana vitrectormy. The levels of vascular endothelial growth factor, connective tissue growth factor and pigment epithelium-derived factor were assessed by using ELISA technique. RESULTS AND CONCLUSION:The levels of connective tissue growth factor and pigment epithelium-derived factor in the aqueous humor of two Avastin injection groups were increased significantly compared to the group with single pars plana vitrectormy. However, the level of vascular endothelial growth factor was lower in the Avastin injection groups. In addition, there was no significant difference between two Avastin injection groups. These results reveal that intravitreous injection of Avastin assisted vitrectomy for proliferative diabetic retinopathy is more effective than single pars plana vitrectormy treatment. The underlying mechanisms may be that Avastin could inhibit the intraocular angiogenesis by not only reducing the secretion of some growth factors but also increasing the levels of anti-angiogenesis related cytokines.