Diabetic Macular Oedema

Diabetic macular oedema (DMO) is a major cause of blindness that has an increasing prevalence associated with the general population in diabetes worldwide. In DMO, increased expression of factors including vascular endothelial growth factor (VEGF) disrupts the blood– retina barrier causing leakage and accumulation of extracellular fluid in the macula with resultant loss of vision. Focal and grid laser photocoagulation has been used to treat DMO for many years, but can cause scarring and atrophy. Vitrectomy is also associated with undesirable effects and its use is mainly confined to tractional DMO cases. Intravitreal steroids have been used successfully but are associated with increased intraocular pressure and cataracts. The intravitreal anti-VEGF treatments have shown improved vision and reduced macular thickness in DMO with good tolerability. Among these, ranibizumab is the only treatment approved in the US and EU for this indication. Its use is supported by extensive clinical trials in which it was shown to be effective with or without laser treatment. Ranibizumab is cost-effective and is likely to have a continuing role in DMO therapy.