Anti-VEGF drugs compared with laser photocoagulation for the treatment of diabetic retinopathy: a systematic review and meta-analysis
Authors: Simmonds Mark , Llewellyn Alexis , Walker Ruth , Fulbright Helen , Walton Matthew , Hodgson Rob , Bojke Laura , Stewart Lesley , Dias Sofia , Rush Thomas , Lawrenson John G , Peto Tunde , Steel David 
Published: December 2024

Background
Diabetic retinopathy is a major cause of sight loss in people with diabetes. The most severe form, proliferative diabetic retinopathy, carries a high risk of vision loss, vitreous haemorrhage, macular oedema and other harms. Panretinal photocoagulation is the primary treatment for proliferative diabetic retinopathy. Anti-vascular endothelial growth factor drugs are used to treat various eye conditions and may be beneficial for people with diabetic retinopathy.

Objective
To investigate the efficacy and safety of anti-vascular endothelial growth factor therapy for the treatment of diabetic retinopathy when compared to panretinal photocoagulation.

Methods
A systematic review and network meta-analysis of all published randomised controlled trials comparing anti-vascular endothelial growth factor (alone or in combination with panretinal photocoagulation) to panretinal photocoagulation in people with diabetic retinopathy. The database searches were updated in May 2023. 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 proliferative diabetic retinopathy. Overall, anti-vascular endothelial growth factor was slightly better than panretinal photocoagulation at preventing vision loss, measured as best corrected visual acuity, at up to 2 years follow-up [mean difference in the logarithm of the minimum angle of resolution −0.089 (or 3.6 Early Treatment Diabetic Retinopathy Study letters), 95% confidence interval −0.180 to −0.019]. There was no clear evidence of any difference between the anti-vascular endothelial growth factors, but the potential for bias complicated the comparison. One trial found no benefit of anti-vascular endothelial growth factor over panretinal photocoagulation after 5 years. Anti-vascular endothelial growth factor was superior to panretinal photocoagulation at preventing macular oedema (relative risk 0.29, 95% confidence interval 0.18 to 0.49) and vitreous haemorrhage (relative risk 0.77, 95% confidence interval 0.61 to 0.99). There was no clear evidence that the effectiveness of anti-vascular endothelial growth factor varied over time.

Conclusions
Anti-vascular endothelial growth factor injections reduce vision loss when compared to panretinal photocoagulation, but the benefit is small and unlikely to be clinically meaningful. Anti-vascular endothelial growth factor may have greater benefits for preventing complications such as macular oedema. Observational studies extending follow-up beyond the 1-year duration of most trials are needed to investigate the longer-term effects of repeated anti-vascular endothelial growth factor injections.

Funding
This article presents independent research funded by the National Institute for Health and Care Research (NIHR) Health Technology Assessment programme as award number NIHR132948.