Ranibizumab and diabetic macular oedema: after laser therapy.

Diabetic retinopathy is sometimes accompanied by macular oedema, leading to a marked decline in visual acuity. The standard treatment, in addition to glycaemic and blood pressure control, is laser photocoagulation, despite its modest efficacy. Ranibizumab (Lucentis, Novartis), a VEGF (vascular endothelial growth factor) inhibitor, was initially authorised for age-related macular degeneration (AMD) in the European Union. It is now also approved for the treatment of visual loss due to macular oedema in diabetic patients. In this setting, clinical evaluation of ranibizumab is mainly based on two double-blind randomised trials comparing ranibizumab + laser photocoagulation versus placebo + laser photo-coagulation in a total of about 1000 patients. Compared with placebo, addition of ranibizumab to laser therapy led to a marked improvement in visual acuity in approximately 15% of patients after 12 months of treatment. The improvement appeared to persist after 24 months of treatment. In a trial that included a group treated with ranibizumab alone, efficacy did not differ from that of the ranibizumab + laser combination. Uncertainties remain concerning the long-term efficacy of ranibizumab and its benefits in patients with poorly controlled diabetes or proliferative retinopathy. The adverse effect profile of ranibizumab in patients with diabetic macular oedema is similar to that reported in patients with AMD, and mainly includes ocular adverse effects such as pain, bleeding and increased intraocular pressure. A risk of systemic adverse effects, particularly cardiovascular disorders, should be kept in mind in case of long-term treatment. Ranibizumab can cause birth defects, even after intravitreal injection during pregnancy. Monthly treatment with ranibizumab is inconvenient, difficult and expensive. In practice, laser therapy remains the standard treatment for diabetic patients with significantly reduced visual acuity due to macular oedema. Ranibizumab, which requires intravitreal injections, should be restricted to second-line use.