Anti-VEGF drugs compared with laser photocoagulation for the treatment of diabetic retinopathy : a systematic review and meta -analysis

Background Diabetic retinopathy is a major cause of sight loss in people with diabetes. The most severe form, proliferative diabetic retinopathy (PDR), carries a high risk of vision loss risk, vitreous haemorrhage, macular oedema and other harms. Panretinal photocoagulation (PRP) is the primary treatment for PDR. Anti-vascular endothelial growth factor (anti-VEGF) drugs are used to treat various eye conditions and may be beneficial for people with diabetic retinopathy. Objective To investigate the efficacy of anti-VEGF therapy for the treatment of diabetic retinopathy when compared to PRP. Methods A systematic review and network meta-analysis of all published randomised controlled trials comparing anti-VEGF (alone or in combination) to PRP in people with diabetic retinopathy. Trials where the primary focus was treatment of macular oedema or vitreous haemorrhage were excluded. Results A total of 14 trials were included: 3 of aflibercept, 5 of bevacizumab and 6 of ranibizumab. Two trials were of patients with non-proliferative diabetic retinopathy ); all others were in PDR. Overall anti-VEGF was better than PRP at preventing vison loss, measured as best corrected visual acuity (BCVA), at up to two years follow-up (BCVA mean difference in logMAR -0.064, 95% confidence interval (CI) -0.122 to -0.015). There was no clear evidence of any difference between the anti-VEGFs, but potential for bias and differences in trial complicated the comparison. Anti-VEGF was superior to PRP at preventing macular edema (Relative risk 0.29, 95% CI 0.18 to 0.49) and vitreous haemorrhage (Relative risk 0.77, 95% CI 0.61 to 0.99). There was no evidence that the effectiveness of anti-VEGF varied over time, but one trial found no benefit of anti-VEGF over laser therapy after 5 years. Conclusions Anti-VEGF injection appears to be superior to using laser photocoagulation, but the benefit in preservation of eyesight appears to be modest. Long-duration observational studies are needed to examine how anti-VEGF may be beneficial in the long term.