title: Clinical outcome after switching therapy from ranibizumab and/or bevacizumab to aflibercept in central retinal vein occlusion.
abstract: OBJECTIVE
  After 48 months, unresolved macular edema secondary to central retinal vein occlusion (CRVO) is present in more than half of the patients treated with ranibizumab/bevacizumab. Switching therapy to aflibercept, a more recent vascular endothelial growth factor-A (VEGF-A) inhibitor, as well as VEGF-B and placental growth factor inhibitor, might improve the clinical outcome in patients with CRVO who respond insufficiently to ranibizumab/bevacizumab.
  
  
  METHODS
  The presented study is a retrospective analysis of CRVO patients (n = 13) responding insufficiently to ranibizumab and/or bevacizumab (requiring treatment every 6 weeks or more frequently). Treatment in these patients was switched to aflibercept, which was administered based on a 'treat and extend' regime. The injection interval, relapse-free interval, central retinal thickness, central retinal volume, visual acuity, and intraocular pressure (IOP) were evaluated prior to switching to aflibercept and at month 6 and year 1 after switching therapy.
  
  
  RESULTS
  From baseline to year 1 after switching therapy to aflibercept, the mean injection interval (primary end point) increased by 0.51 months (p = 0.023) and the relapse-free interval by 3.02 weeks (p = 0.003). The mean central retinal thickness decreased by 195.84 µm and the mean central retinal volume (6 mm diameter) by -1.81 mm3 (p = 0.007). Correspondingly, the mean ETDRS score increased from 66.15 at baseline to 76.54 letters at year 1 after switching therapy to aflibercept (+10.38 letters, p = 0.021). The IOP was not statistically significantly affected (-1.2 mm Hg, p = 0.196).
  
  
  CONCLUSIONS
  Switching therapy from intravitreal ranibizumab/bevacizumab to aflibercept in insufficiently responding macular edema secondary to CRVO elongates the injection interval and the relapse-free interval and provides an improved anatomical as well as functional outcome.
authors.affiliation: Stadtspital Triemli, Zurich, Switzerland.
authors.forename: Maximilian
authors.initials: M
authors.lastname: Pfau
authors.forename: Heidi
authors.initials: H
authors.lastname: Fassnacht-Riederle
authors.forename: Matthias D
authors.initials: MD
authors.lastname: Becker
authors.forename: Nicole
authors.initials: N
authors.lastname: Graf
authors.forename: Stephan
authors.initials: S
authors.lastname: Michels
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D020533:Angiogenesis Inhibitors / Q000627:therapeutic use*; D000068258:Bevacizumab / Q000627:therapeutic use*; D057915:Drug Substitution; D005260:Female; D006801:Humans; D058449:Intravitreal Injections; D008269:Macular Edema / Q000188:drug therapy* / Q000209:etiology / Q000503:physiopathology; D008297:Male; D000069579:Ranibizumab / Q000627:therapeutic use*; D040262:Receptors, Vascular Endothelial Growth Factor / Q000627:therapeutic use*; D011993:Recombinant Fusion Proteins / Q000627:therapeutic use*; D012160:Retina / Q000473:pathology; D012170:Retinal Vein Occlusion / Q000150:complications / Q000188:drug therapy* / Q000503:physiopathology; D012189:Retrospective Studies; D041623:Tomography, Optical Coherence; D016896:Treatment Outcome; D042461:Vascular Endothelial Growth Factor A / Q000037:antagonists & inhibitors; D014792:Visual Acuity / Q000187:drug effects
chemical_list: D020533:Angiogenesis Inhibitors; D011993:Recombinant Fusion Proteins; C467484:VEGFA protein, human; D042461:Vascular Endothelial Growth Factor A; C533178:aflibercept; D000068258:Bevacizumab; D040262:Receptors, Vascular Endothelial Growth Factor; D000069579:Ranibizumab