A systematic review on the effect of bevacizumab in exudative age-related macular degeneration

Aim To provide evidence for the effect of bevacizumab on visual acuity (VA) and central retinal thickness (CRT) in exudative age-related macular degeneration Methods A systematic review of all articles of bevacizumab for exudative AMD was conducted. Articles published up to March 2008 were identified in Medline, Embase, the Cochrane Controlled Trials Register and references from included articles. Search terms were "Bevacizumab or Avastin" and "Macula* or ARMD or AMD or intra(-) vitreal or intra(-)vitreous". Three observers participated in the data retrieval and assignment of the quality scores. Results A total of 561 articles were retrieved. Three randomised controlled trials (RCT) and 23 before-and-after studies of patients (n=1,435) who had received bevacizumab were published. Inclusion criteria varied. Lack of masking was the main methodological shortcoming. These RCTs showed that bevacizumab is more effective than PDT. Bevacizumab was given intravenously or as intra-vitreal injection. The latter was given once, or repeatedly every 4 weeks, and with or without additional injection when a recurrence occurred, mostly based on visual acuity and/or findings from optical coherence tomography. After intravenous administration, the weighted mean change in VA was +12.8 ETDRS letters ( range +11 to +14) and the weighted mean change for CRT was - 129 mu m (range - 100 to -202). For the 23 studies with intravitreal injections, the change in VA was +8.6 letters ( range +2 to +26) and the change in CRTwas -90 mu m ( range -46 to -190). The incidence of adverse events was low. The change in VA was 2.7 letters higher for studies with a higher quality vs lower quality. Conclusion Visual acuity improves and central retinal thickness decreases in patients with exudative AMD after bevacizumab. There is no reasonable doubt that this is caused by bevacizumab. It is likely that a randomised controlled trial will show that bevacizumab is equivalent in effect to ranibizumab, which showed a change in ETDRS of +5.9 letters for occult or minimally classic CNV and +9.8 letters for classic CNV after three monthly injections in two large RCTs.