A Systematic Review of Clinical Studies Using VEGF Inhibitors in the Treatment of Macular Edema from Diabetic Retinopathy

Purpose: To synthesize the present clinical evidence of efficacy and adverse events of commonly used anti-VEGF drugs for Diabetic Macular Edema. Methods: A systematic review was undertaken from the Medline, Biosis, CINAHL, Cochrane and Web of Science databases. Grey literature that consisted of lectures, seminars and conferences was also retrieved. The cut-off date was January 1 2014. A two-stage screening process was undertaken followed by a data extraction stage using the systematic review software EPPI. These were done by two reviewers. Heterogeneous meta-analysis was performed on the primary outcome which was change in macular thickness from baseline after injection. Side effects were tabulated. Results: From 846 articles that were initially screened, 18 papers were included in the data extraction stage. For all anti-VEGF treatments, the average decrease in macular thickness was 114.4 microns (95% CI: 66.8 - 162 μM). The average decrease in thickness from Lucentis (161.9 μM) was larger than that for Avastin (96.5 μM) but this was not statistically significant (p = 0.23). The most common complications were vitreous hemorrhage, endophthalmitis and retinal detachment. Vision threatening complications were rare but were reported regularly. Conclusions: The synthesized clinical evidence to date supports both of these treatments as efficacious and safe for diabetic macular edema (DME). There is a trend toward greater efficacy for Lucentis over Avastin but this is not statistically significant and will need a head-to-head RCT to assess accurately.