Authors: Wang Yunpeng, Chen Xiaohong, Chen Meizhu
Abstract [Download PDF] [Read Full Text]
Intraocular neovascularization is a primary cause of visual reduce in proliferative diabetic retinopathy (PDR), and intravitreal injection of ranibizumab is one of treating approachs.Researching the mechanism of intravitreal injection of ranibizumab for PDR is a new target for the prevention and management of PDR.
This study was to determine the levels of vascular endothelial growth factor (VEGF) and pigment epithelium-derived factor (PEDF) in aqueous humor of PDR eyes before and after intravitreal injection of ranibizumab.
Self-controlled observational study was designed.Fifteen eyes of 15 PDR patients with type 2 diabetes mellitus were included in Fuzhou General Hospital of Nanjing Military Command from January to August 2014, and 1 eye combined with neovascular glaucoma and iris rubeosis.Aqueous samples of 0.1 ml at each time were collected before and 7 days after the injection of ranibizumab from all patients under the informed consent.The changes of aqueous VEGF and PEDF concentrations were detected and analyzed by enzyme-linked immunosorbent assay.This study complied with Declaration of Helsinki and the protocol was approved by this hospital.
The freeVEGF concentrations before and 7 days after intravitreal injection were (179.4±136.5) pg/ml and (27.1±23.5) pg/ml, respectively, showing a significant reduce after intravitreal injection of ranibizumab (t=4.172, P=0.001). PEDF concentrations before and 7 days after intravitreal injection were (394.0±237.2) pg/ml and (267.7±199.6) pg/ml, respectively, showing a significant reduce after intravitreal injection of ranibizumab (t=5.443, P=0.000). Intraocular neovascularization vanished after intravitreal injection of ranibizumab and vitrectomy was carried out at the seventh day after intravitreal injection.
Free VEGF and PEDF levels in aqueous humor appear to be significantly decreased after intravitreal injection of ranibizumab, and ocular neovascularization disappears at same time, which avoids intraoperative bleeding during vitrectomy.