title: Prolongation of injection interval after switching therapy from ranibizumab to aflibercept in Japanese patients with macular edema secondary to branch retinal vein occlusion.
abstract: OBJECTIVE
  This study was conducted to investigate the outcome of switching therapy from ranibizumab to aflibercept in Japanese patients with macular edema (ME) secondary to branch retinal vein occlusion (BRVO) in daily practice.
  
  
  METHODS
  This retrospective study enrolled 15 eyes in 15 Japanese patients with ME secondary to BRVO who had been receiving a pro re nata regimen of ranibizumab and had provided written informed consent to switch to aflibercept therapy. The intravitreal injection interval, central retinal thickness, and visual acuity were evaluated before and after switching.
  
  
  RESULTS
  The mean period of ranibizumab treatment was 11.8±4.2 months. The mean observation period after switching to aflibercept was 10.6±3.4 months, and seven patients were observed for more than 12 months after switching. The mean intravitreal injection interval was prolonged by 23.6 days with aflibercept (68.2±26.4 days with ranibizumab vs 91.8±33.2 days with aflibercept;P=0.0011). The mean intravitreal injection interval just before the switch was 81.3±35.6 days and was significantly prolonged to 100.8±34.2 days just after the switch to aflibercept (P=0.0309). The mean central retinal thickness did not change before or after the switch to aflibercept (295±55 μm with ranibizumab vs 276±25 μm with aflibercept;P=0.12). The mean visual acuity also remained at an improved level after the switch. No systemic or ocular side effects were evident during the study period.
  
  
  CONCLUSIONS
  Switching therapy from ranibizumab to aflibercept in Japanese patients with ME secondary to BRVO prolonged the intravitreal injection interval without anatomical or functional degradation.
authors.affiliation: Ophthalmology Department, Eye Center, Kobe Kaisei Hospital, Kobe, Hyogo, Japan.
authors.forename: Mizuki
authors.initials: M
authors.lastname: Tagami
authors.affiliation: Ophthalmology Department, Eye Center, Kobe Kaisei Hospital, Kobe, Hyogo, Japan.
authors.forename: Ryuto
authors.initials: R
authors.lastname: Sai
authors.affiliation: Ophthalmology Department, Eye Center, Kobe Kaisei Hospital, Kobe, Hyogo, Japan.
authors.forename: Masahide
authors.initials: M
authors.lastname: Fukuda
authors.affiliation: Ophthalmology Department, Eye Center, Kobe Kaisei Hospital, Kobe, Hyogo, Japan.
authors.forename: Atsushi
authors.initials: A
authors.lastname: Azumi
keywords: aflibercept; branch retinal vein occlusion; macular edema; ranibizumab