VEGF Suppression Times in DME Treated With Ranibizumab
VEGF Suppression Times in DME Treated With Ranibizumab
Background To measure vascular endothelial growth factor (VEGF) levels in aqueous humour from patients with diabetic macular oedema (DME) treated with ranibizumab and to determine how long VEGF was suppressed.
Methods In this nonrandomised, prospective clinical study, 17 eyes of 17 patients were included in the study. A total of 110 aqueous humour samples were taken before an intravitreal ranibizumab injection in patients with DME. VEGF-A was measured by Luminex multiplex bead analysis (Luminex Inc, USA).
Results VEGF was completely suppressed in all patients after ranibizumab injections for a mean of 33.7 days (SD±5.1, range 27–42, median 34). VEGF suppression times were individually stable during the observation time of up to 16 months. There was no statistically significant difference of VEGF levels at baseline and before the beginning of a new injection series (123.6 pg/mL vs 125.1 pg/mL; p=1.0, Wilcoxon).
Conclusions Monthly ranibizumab injections lead to a complete VEGF suppression in patients with DME. The long-term stability and the range of suppression times among individuals suggest that some patients could benefit from individual injection intervals.
Diabetic macular oedema (DME) is a frequent cause of vision loss in patients with diabetes. The development of DME as a consequence of vascular leakage can occur in any stage of disease. Vascular endothelial growth factor (VEGF) is a key player in the pathogenesis of DME. It is elevated in both vitreous and anterior chamber, and the levels correlate with the severity of DME. Laser photocoagulation has been the standard treatment for DME, but clinical trials have shown that targeting VEGF with ranibizumab is superior for the preservation and improvement of visual acuity (VA). While many studies have analysed morphology and function of the retina under ranibizumab treatment, little is known about the levels of VEGF in the eye in response to treatment in spite of its importance as the primary target of the intervention. VEGF levels can be monitored in aqueous humour as the anterior chamber is easily accessible and vitreous and aqueous levels are highly correlated.
Bevacizumab, which is another anti-VEGF drug, suppressed VEGF levels in the anterior chamber for at least 4 weeks after the injection.
The aim of this study was to measure VEGF levels in aqueous humour from patients with DME treated with ranibizumab and to determine how long VEGF was suppressed.
Abstract and Introduction
Abstract
Background To measure vascular endothelial growth factor (VEGF) levels in aqueous humour from patients with diabetic macular oedema (DME) treated with ranibizumab and to determine how long VEGF was suppressed.
Methods In this nonrandomised, prospective clinical study, 17 eyes of 17 patients were included in the study. A total of 110 aqueous humour samples were taken before an intravitreal ranibizumab injection in patients with DME. VEGF-A was measured by Luminex multiplex bead analysis (Luminex Inc, USA).
Results VEGF was completely suppressed in all patients after ranibizumab injections for a mean of 33.7 days (SD±5.1, range 27–42, median 34). VEGF suppression times were individually stable during the observation time of up to 16 months. There was no statistically significant difference of VEGF levels at baseline and before the beginning of a new injection series (123.6 pg/mL vs 125.1 pg/mL; p=1.0, Wilcoxon).
Conclusions Monthly ranibizumab injections lead to a complete VEGF suppression in patients with DME. The long-term stability and the range of suppression times among individuals suggest that some patients could benefit from individual injection intervals.
Introduction
Diabetic macular oedema (DME) is a frequent cause of vision loss in patients with diabetes. The development of DME as a consequence of vascular leakage can occur in any stage of disease. Vascular endothelial growth factor (VEGF) is a key player in the pathogenesis of DME. It is elevated in both vitreous and anterior chamber, and the levels correlate with the severity of DME. Laser photocoagulation has been the standard treatment for DME, but clinical trials have shown that targeting VEGF with ranibizumab is superior for the preservation and improvement of visual acuity (VA). While many studies have analysed morphology and function of the retina under ranibizumab treatment, little is known about the levels of VEGF in the eye in response to treatment in spite of its importance as the primary target of the intervention. VEGF levels can be monitored in aqueous humour as the anterior chamber is easily accessible and vitreous and aqueous levels are highly correlated.
Bevacizumab, which is another anti-VEGF drug, suppressed VEGF levels in the anterior chamber for at least 4 weeks after the injection.
The aim of this study was to measure VEGF levels in aqueous humour from patients with DME treated with ranibizumab and to determine how long VEGF was suppressed.