Comparison of intravitreal dexamethasone implant and anti-VEGF drugs in the treatment of retinal vein occlusion-induced oedema: a meta-analysis and systematic review

Objective To compare the efficacy and safety of intravitreal dexamethasone (DEX) implant and anti-vascular endothelial growth factor (anti-VEGF) agents in the treatment of macular oedema secondary to retinal vein occlusion (RVO). Design Systematic review and meta-analysis based on Grading of Recommendations Assessment, Development and Evaluation (GRADE). Data sources PubMed, Cochrane Library and ClinicalTrials.gov registry were searched from inception to 10 December 2019, without language restrictions. Eligibility criteria Randomised controlled trials (RCTs) and real-world observation studies comparing the efficacy of DEX implant and anti-VEGF agents for the treatment of patients with RVO, naive or almost naive to both arms, were included. Data extraction and synthesis Two reviewers independently extracted data for mean changes in best-corrected visual acuity (BCVA), central subfield thickness (CST) and product safety. Review Manager V.5.3 and GRADE were used to synthesise the data and validate the evidence, respectively. Results Four RCTs and 12 real-world studies were included. An average lower letter gain in BCVA was determined for the DEX implant (mean difference (MD) = −6.59; 95% CI −8.87 to −4.22 letters) administered at a retreatment interval of 5–6 months. Results were similar (MD6 months=−12.68; 95% CI −21.98 to −3.37 letters; MD12 months=−9.69; 95% CI −12.01 to −7.37 letters) at 6 and 12 months. The DEX implant resulted in comparable or marginally less CST reduction at months 6 and 12 but introduced relatively higher risks of elevated intraocular pressure (RR=3.89; 95% CI 2.16 to 7.03) and cataract induction (RR=5.22; 95% CI 1.67 to 16.29). Most real-life studies reported an insignificant numerical gain in letters for anti-VEGF drugs relative to that for DEX implant. However, the latter achieved comparable efficacy with a 4-month dosage interval. Conclusion Compared with anti-VEGF agents, DEX implant required fewer injections but had inferior functional efficacy and safety. Real-life trials supplemented the efficacy data for DEX implant.