PURPOSE Diabetic macular oedema (DMO) is a leading cause for visual impairment in the working age population in the UK. Ranibizumab has been shown to be effective in treatment of DMO in studies based on mainly Caucasian populations. This study reports the 12-month outcome in a cohort of South Asian subjects with DMO treated with ranibizumab.MethodsDMO in 51 eyes of 41 South Asian patients was treated with ranibizumab 0.5 mg according to the modified DRCRnet protocol I. Visual acuity (VA) and central macular thickness (CMT) were recorded at baseline, 3, 6, and 12 months. Results were compared for eyes with different baseline visual acuities and different baseline macular thicknesses.RESULTS Over the 12-month period, the mean ETDRS VA increased from 55.3±13.4 letters to 63.8±15.2 letters for all eyes. At 12 months, 70.6% eyes gained 5 or more letters acuity and 17.6% eyes gained 15 letters or more. During the same period, the mean CMT decreased from 532±129 to 318±136 μm. Eyes that had received previous laser treatments had a mean letter gain of 9.2 letters, compared with 8.5 for all eyes at 12 months.CONCLUSIONS Ranibizumab 0.5 mg is safe and effective at reversing vision loss due to DMO in patients of South Asian origin at 12 months. Ranibizumab treatment appears to be effective in patients with longstanding DMO who received prior laser treatments. Further studies are needed to define the long-term outcome in patients of different ethnicity and DMO.