OBJECTIVES: Compare the efficacy of therapies in the treatment of visual impairment due to diabetic macular edema. METHODS: A systematic review was conducted to identify relevant randomized control trials (RCTs). RCTs reporting 6- or 12-month results for ranibizumab, aflibercept, laser or sham were included. The analysed outcomes were best-corrected visual acuity (BCVA) measured as the proportion of patients gaining at least 10 letters or 15 letters. Efficacy comparisons were made using a Bayesian network meta-analysis with random treatment effects adjusting for baseline BCVA.  RESULTS: The analysis included 2634 patients from 10 RCTs (including DRCR-net Protocol T). For the percentage of patients who gained ≥10 letters, ranibizumab 0.5 mg pro re nata(PRN) was numerically superior to aflibercept (OR, 1.6; 95% credible interval [CrI], 0.6–5.4). The odds of gaining ≥ 15 letters were the same for ranibizumab 0.5 mg PRN and aflibercept 2q8 (OR, 1.0; 95% CrI, 0.3–5.9 for PRN). Similar findings were found for ranibizumab 0.5 mg treat and extent (T&E). The probability that ranibizumab 0.5 PRN was a better treatment than aflibercept was 84% for patients gaining ≥ 10 letters and 51% for patients gaining ≥ 15 letters. The odds-ratio of gaining ≥ 10 letters with ranibizumab 0.5 mg (PRN or T&E) vs. 0.3 mg PRN was 2.3 (95% CrI: 0.5-16.6) and 2.0 (95% CrI: 0.4-30.7) for ≥ 15 letters. The probability that ranibizumab 0.5 mg was superior to 0.3 mg PRN was 89% for patients gaining ≥ 10 letters and 82% for patients gaining ≥ 15 letters.  CONCLUSIONS: Ranibizumab 0.5 mg patients had a higher probability of gaining ≥ 10 letters than aflibercept patients and had similar probabilities of gaining ≥ 15 letters as aflibercept. Ranibizumab 0.5 mg has a higher probability of being the best treatment than ranibizumab 0.3 mg PRN.