Four studies (445 patients, 492 eyes) were included in the review. Sample sizes ranged from 97 to 129 patients. Two studies scored 2 and single studies scored 4 and 5 points on the Jadad scale. The studies with lower scores did not use appropriate randomisation or double-blinding. Follow-up ranged from 12 to 36 weeks. Attrition ranged from 0% to 17%.
At six weeks follow-up, statistically significant benefits were associated with treatment with intravitreal bevacizumab in visual acuity compared to macular photocoagulation (WMD -0.09, 95% CI -0.15 to -0.02; Ι²=3%; four trials) and intravitreal bevacizumab combined with triamcinolone acetonide (WMD -0.07, 95% CI -0.14 to 0.00; Ι²=0%; three trials). There were no significant differences in visual acuity for the comparison of intravitreal bevacizumab with other treatments at 12 weeks follow-up (three trials).
Statistically significant reductions in central macular thickness were observed in patients treated with intravitreal bevacizumab at six weeks follow-up compared to patients who received macular photocoagulation (WMD -30.36, 95% CI -54.12 to -6.60; Ι²=0%; three trials). Differences between intravitreal bevacizumab and macular photocoagulation were not significant at 12 weeks follow-up (three trials). There were no differences between intravitreal bevacizumab and combination treatment of intravitreal bevacizumab plus triamcinolone acetonide at six weeks follow-up (three trials) and 12 weeks follow-up (four trials).
No injection-related adverse events were reported. One patient developed endophthalmitis. Cases in other studies of mild anterior chamber reaction and ocular hypertension resolved spontaneously after one week.
Sensitivity analyses found significant benefits of intravitreal bevacizumab in visual acuity compared to all alternative treatments at 12 weeks follow-up for two studies with scores of at least 3 on the Jadad scale (WMD -0.09, 95% CI -0.16 to -0.02; Ι²=0%).