6 letters at 1 year of follow-up. Although both groups achieved a significant improvement in mean BCVA, IV ranibizumab eyes demonstrated significantly greater BCVA gains when compared with IV bevacizumab eyes at weeks 8 and 32 and a trend toward significance find more at weeks 28, 36, and 40. This difference between the groups
at these time points during follow-up may be attributable to lower central subfield thickness values in the IV ranibizumab group compared with the IV bevacizumab group at these periods (Figure 2, Top) and, consequently, a significantly higher proportion of patients with a central subfield thickness ≤275 μm in the IV ranibizumab group (Figure 3). Correspondingly, the proportion of IV bevacizumab eyes that met the criterion for rescue therapy was significantly higher in the IV bevacizumab group compared with the IV ranibizumab
group. Despite significant differences between groups in BCVA at weeks 8 and 32, it is important to note that because the sample size calculation for this study was based on the difference between treatment groups with respect to central subfield thickness, conclusions regarding BCVA are limited: the lack of a significant difference between treatment groups with respect to BCVA at some study visits does not necessarily indicate that both anti-VEGF treatments have an equivalent effect on BCVA. In other words, a significant difference between groups may have been detected at other study visits if the study had been conducted with a sample size based on differences in BCVA rather VE-821 than on differences in central
subfield thickness. Significant improvements in central subfield thickness compared with baseline were observed in both the IV bevacizumab and IV ranibizumab groups. At week 48, both groups demonstrated a mean central subfield thickness reduction compared with baseline of 120 μm. Similarly, the DRCR.net12 reported a mean improvement in central subfield thickness of 131 μm and 137 μm in patients with DME treated with IV ranibizumab of plus prompt or deferred laser, respectively, after 1-year follow-up. More recently, the RISE and RIDE13 studies reported a mean central subfield thickness reduction at 1 year of 250 μm in patients with DME treated with IV ranibizumab. The greater absolute value of central subfield thickness reduction observed in the RISE and RIDE studies may be related to higher baseline central foveal thickness values and/or more constant VEGF blockage with monthly treatment compared to the DRCR.net study,12 in which the mean number of injections was 8 per year, and the present study, in which the mean number of injections was 7.67 per year. It is also important to note that the multivariate analysis in the current study did not demonstrate any influence of baseline central subfield thickness on the number of injections in either study group.