Abstract
Purpose: :
To evaluate the changes in serum concentrations of vascular endothelial growth factor (VEGF) after intravitreal bevacizumab treatment in patients with macular edema (ME) secondary to diabetic retinopathy(DR) and neovascular age-related macular degeneration (AMD).
Methods: :
Treatment-naive 120 patients (120 eyes) with ME due to DR (group A: 60 eyes) and neovascular AMD (group B: 60 eyes) were enrolled. All patients were treated with three consecutive injections of 1.25 mg bevacizumab at 0,6,12 weeks. Serial venous samples at baseline and 6 weeks after each injection were obtained. Visual acuity (VA) and central macular thickness (CMT) using optical coherence tomography were measured before each injection. We measured the serum concentrations of VEGF using immunoassays (ELISA) in each group of 60 eyes and compared these findings with those of 60 eyes age-matched control group.
Results: :
Compared to the control group (52±8.5 pg/ml), the serum VEGF concentrations of group A (316.9±71.3 pg/ml, p<0.001 ) and group B (270.1± 45.2 pg/ml, p<0.001) were significantly increased before the injection. There was no significant difference between two groups at baseline (p=0.867). In both groups, serum VEGF levels significantly decreased to 242.8±21.3 pg/ml and 148.1±31.3 pg/ml after the first injection (p =0.038, p<0.001, respectively) and to 117.5±19.3 pg/ml and 41.2±39.5 pg/ml after the second injection (p<0.001, p<0.001, respectively). However, there was no statistically significant reduction after third injection (115.9±39.3 pg/ml and 38.9±21.5 pg/ml) in both groups. Compared with group A , the VEGF concentrations of group B were significantly decreased after every each injection (p=0.003, p<0.001, p<0.001, respectively).
Conclusions: :
Significantly decreased serum VEGF levels were noted after the first and the second injection of bevacizumab along with an increase in VA and a decrease in CMT. The reason of significant high VEGF level in DME group in comparison with neovascular AMD group is considered as the influence of systemic microcirculation insufficiency in diabetes patients on the production level of serum VEGF.
Clinical Trial: :
http://www.schmc.ac.kr/, 2009-79
Keywords: vascular endothelial growth factor • diabetic retinopathy • age-related macular degeneration