A Cochrane review included 4 studies with a total of 428 subjects. 3 studies included people with diabetic macular oedema (DMO) that was refractory to laser photocoagulation and 1 study included previously untreated patients. 3 studies had more than 2 randomisation groups generating 5 types of comparisons overall.
One small study (n=78) suggested some short-term benefit with bevacizumab compared to placebo in patients with clinically significant macular oedema (CSMO) that was refractory to photocoagulation (mean change of visual acuity (logMAR) in the bevacizumab groups was -0.21 logMAR better, 95% CI -0.37 better to -0.05 better) and another study (n=87) suggested some benefit compared to photocoagulation in previously untreated patients (mean change of visual acuity (logMAR) in the bevacizumab groups was -0.29 logMAR better, 95% CI -0.42 better to -0.16 better). There were no statistically significant differences between pegaptanib and sham treatment (1 study, n=171). No difference could be demonstrated in 1 study (n=26) comparing bevacizumab to triamcinolone (both administered with a single injection) and between bevacizumab and bevacizumab plus triamcinolone in 2 studies (n=182). There were no serious adverse effects in these short-term studies, except for one case of severe anterior uveitis in one eye treated with bevacizumab. No included study examined long-term adverse effects of antiangiogenic therapy.
Comment: The quality of evidence is downgraded by inconsistency (variability in results across studies and heterogeneity in interventions and outcomes), by indirectness (only short-term outcomes (24 to 36 weeks) were reported) and by imprecise results (limited study size for each comparison).