Laser Therapy Combined With Intravitreal Aflibercept vs Intravitreal Aflibercept Monotherapy (LADAMO)

Inclusion Criteria: * At screening, the study eye must have DMO with retinal thickness \> 300 microns in central 1mm subfield on Spectral domain OCT * Age \>= 18 years * Diagnosis of diabetes mellitus * Best corrected visual acuity of 35-79 LogMAR letters at 4 meters (approximately 6/7.5-6/60) in the study eye * Women of childbearing potential must have a negative urine pregnancy test at the screening visit and prior to treatment. A woman is considered of childbearing potential unless she is postmenopausal and without menses for 12 months or is surgically sterilised * Peripheral retinal ischaemia affecting an area greater than 10 disc diameters of the wide-field fundus fluorescein angiogram (as per the Central Vein Occlusion Study) * Centre involving DMO, which in the opinion of the investigator, would not benefit from focal macular laser treatment (e.g. diffuse leak from the capillary bed, disruption of the foveal avascular zone or perifoveal capillary dropout, complete macular grid laser). * Written informed consent has been obtained Exclusion Criteria: * Known allergy to aflibercept or agents used in the study * Women who are pregnant, nursing, or planning a pregnancy, or who are of childbearing potential and not using reliable means of contraception * Loss of vision due to other causes (e.g. age related macular degeneration, myopic macular degeneration, retinal vein occlusion) in the study eye. * Macular oedema due to other causes in the study eye. * Macula hole, vitreo-macular traction or significant epiretinal membrane in the study eye. * An ocular condition that would prevent visual acuity improvement despite resolution of oedema (such as foveal atrophy or substantial premacular fibrosis) * Treatment with intravitreal triamcinolone acetonide (IVTA) within the last 6 months or peribulbar triamcinolone within the last 3 months, or anti-VEGF drugs (bevacizumab, ranibizumab or aflibercept) within the last 2 months in the study eye. * Cataract surgery within the last 3 months in the study eye * Previous PRP laser treatment in the study eye * Previous vitrectomy in study eye * Media opacity including cataract that already precludes adequate macular photography or cataract that is likely to require surgery within 12 months * Intercurrent severe disease such as septicaemia, any condition which would affect follow-up or photographic documentation (e.g. geographical, psycho-social) * History of chronic renal failure requiring dialysis or renal transplant * Blood pressure \>180/110 * Patient has a condition or is in a situation that in the investigator's opinion may put the patient at significant risk, may confound the study results, or may interfere significantly with the patient's participation in the study