Adult patients with centre-involving diabetic macular oedema will be recruited to this single-centre study. Patients will undergo detailed baseline evaluation which will include:~vision testing~optical coherence tomography scanning~fundus fluorescein angiography~microperimetry~colour contrast sensitivity testing~electrophysiological testing~Patients will be randomised 2:1 to receive either ranibizumab intravitreal injection 4-weekly for 48 weeks or modified ETDRS macular laser therapy 12-weekly for 48 weeks.~Both groups of patients will return at 12, 24 and 48 weeks for repeat testing of the parameters evaluated at baseline.
This exploratory study will compare the effects of ranibizumab treatment with conventional macular laser therapy for patients with diabetic macular oedema.~The study hypothesises that treatment with ranibizumab may be superior to laser treatment in terms of improving vision and decreasing retinal thickness.~Patients will be randomised to receive either repeated injections of ranibizumab every 4 weeks for 48 weeks or macular laser therapy every 12 weeks for 48 weeks.~At baseline, and then at 12, 24 and 48 weeks, patients will undergo detailed testing to provide information on the structure and function of the retina with both of these treatments.