Diabetic macular oedema (DMO) is a major cause of visual loss among diabetics, occurring in 14% to 25% of patients depending on age and insulin treatment status.1 In 2006, the International Diabetes Federation showed that diabetes affects 246 million people worldwide—a figure that will rise to 552 million by 2030 (http://www.idf.org/diabetesatlas/5e/theglobal-burden); therefore the burden of care for DMO will be massive worldwide.

Antiangiogenic therapy is an established treatment option in patients with macular oedema due to diabetic retinopathy. A recently published Cochrane review2 has summarised the evidence, showing that intravitreal injections of vascular endothelial growth factor inhibitors can achieve better visual outcomes at 1 year than conventional focal or grid laser photocoagulation. The cost–effectiveness of this treatment, however, has been questioned in the last few years, particularly in the UK where the National Institute for Health and Care Excellence (NICE) has been using sophisticated methods informing cost utility assessment (see http://www.nicedsu.org.uk/).

The Cochrane review found that at 1 year, antiangiogenic therapy can at least double the chance of gaining three or more lines of vision, as well as halve the risk of losing them. This evidence was collected by meta-analysis of 2 studies on bevacizumab (167 participants), 2 on ranibizumab (300 participants) and 1 on aflibercept (221 participants, of whom 89 were used in the analysis). The evidence was judged to be of moderate quality, mainly because there were not enough trials to investigate heterogeneity and the overall sample size did not meet optimal criteria for sample size requirements.2 Better evidence was available for ranibizumab, but there was little power to investigate the difference in drug efficacy. Safety of the drug and the intravitreal injection procedure was good in the trials, but further long-term data are believed to be needed to exclude …