In a randomized controlled study by Arias et el. «Arias L, Caminal JM, Casas L ym. A study comparing...»1 50 patients with choroidal neovascularization secondary to age-related macular degeneration were randomized to either bevacizumab administered once a month for 3 months and thereafter as needed (loading dose, LD) or bevacizumab administered as needed, after the first infection (pro re nata, PRN). During 6 months follow-up, mean visual acuity improved by 13.7 letters (p<0.001) in the LD group and by 4.6 letters in the PRN group (p<0.001). 36% of patients in the LD group compared with 12% in the PRN group gained 15 or more letters (p=0.04). Mean foveal thickness decreased by 91.3 micrometers (p<0.001) in the LD group and 48.2 micrometers in the PRN group (p<0.001).
Comment: Small sample size and short follow-up.
In a randomized controlled study by Barikian et al. «Barikian A, Mahfoud Z, Abdulaal M ym. Induction wi...»2 90 patients with treatment-naïve age-related macular degeneration were randomized in three groups: (1) intravitreal bevacizumab every 2 weeks for 3 consecutive infections, (2) intravitreal bevacizumab every 4 weeks for 3 consecutive injections and (3) intravitreal bevacizumab immediate pro re nata after first injection. After the initial phase, patients were treated pro re nata and followed for 12 months. Mean initial fluid-free interval was 2.4, 3.4, and 3.5 months for biweekly induction, monthly induction, and immediate prn groups, respectively (p=0.03). Significance was lost when corrected for age and sex (p=0.073). Mean improvement in BCVA, central retinal thickness, and total number of injections were similar among the groups at 12 months. Six eyes in the biweekly induction group developed subretinal fibrosis vs no eyes in the other 2 groups (p=0.003).
Comment: Sample size may have been too small to find clinically important differences between groups.
A total of 100 treatment-naive patients with active subfoveal choroidal neovascularisation of minimally classic or occult type, secondary to age-related macular degeneration, were randomized to receive either one injection of bevacizumab at baseline followed by a PRN regimen (NLD) or three 6-weekly injections of bevacizumab followed by PRN (LD) «Menon G, Chandran M, Sivaprasad S ym. Is it necess...»3. Primary end point was best corrected visual acuity. Secondary end points were central macular thickness (CMT) on OCT and adverse events. Proportions of patients with visual stability, defined as 15 or less letter loss from baseline, were 84% in the LD group compared with only 67% in the NLD group (p<0.05). A post hoc analysis comparing the two groups in terms of the mean visual scores turned out to be not statistically significant. There were no between-groups differences in CMT. There were no serious ocular adverse events in either group. In total, there were six treatment-emergent adverse events in the LD group and five in the NLD group.