title: Outcomes of switching treatment to aflibercept in patients with macular oedema secondary to central retinal vein occlusion refractory to ranibizumab.
abstract: OBJECTIVE
  To assess the treatment outcome of switching from ranibizumab to aflibercept intravitreal injections in patients with macular oedema secondary to central retinal vein occlusion (CRVO).
  
  
  METHODS
  A prospective interventional study was conducted in a tertiary retina service in Leicester Royal Infirmary, UK, where patients with CRVO and associated macular oedema were recruited. First-line treatment involved three monthly ranibizumab injections. Non-responders were defined as patients who despite a minimum of three consecutive injections had persistent intraretinal fluid one month after the last injection. In these cases, a treatment change to aflibercept injections on a per-needed basis was decided. Best-corrected visual acuity (BCVA) and central retinal thickness (CRT) were measured before and after switching of treatment. Follow-up period lasted for a minimum of 24 weeks after switching.
  
  
  RESULTS
  Twenty-nine eyes of 29 patients with refractory macular oedema secondary to CRVO were included. All eyes had an average of 4.5 ranibizumab intravitreal injections in a mean period of 6 months without reduction in intraretinal fluid and/or no visual acuity gain. A significant decrease in mean CRT from 633.67 ± 242.42 to 234.62 ± 78.28 μm and improvement in mean BCVA from 1.34 ± 0.66 log MAR to 0.91 ± 0.73 log MAR were noticed after switching treatment to aflibercept. The average number of aflibercept injections needed for oedema resolution was 2.19.
  
  
  CONCLUSIONS
  Aflibercept is an effective alternative treatment for macular oedema secondary to CRVO refractory to ranibizumab. Good anatomical and functional result can be achieved with few injections. The maintenance of these results after 6 months is yet to be investigated.
authors.affiliation: Leicester Royal Infirmary, University Hospitals of Leicester, Infirmary Square, Leicester, LE1 5WW, UK. vasiliskon@hotmail.com.
authors.forename: Vasileios
authors.initials: V
authors.lastname: Konidaris
authors.affiliation: Leicester Royal Infirmary, University Hospitals of Leicester, Infirmary Square, Leicester, LE1 5WW, UK.
authors.forename: Zahra
authors.initials: Z
authors.lastname: Al-Hubeshy
authors.affiliation: Leicester Royal Infirmary, University Hospitals of Leicester, Infirmary Square, Leicester, LE1 5WW, UK.
authors.forename: Konstantinos T
authors.initials: KT
authors.lastname: Tsaousis
authors.affiliation: Leicester Royal Infirmary, University Hospitals of Leicester, Infirmary Square, Leicester, LE1 5WW, UK.
authors.forename: Konstantina
authors.initials: K
authors.lastname: Gorgoli
authors.affiliation: Leicester Royal Infirmary, University Hospitals of Leicester, Infirmary Square, Leicester, LE1 5WW, UK.
authors.forename: Somnath
authors.initials: S
authors.lastname: Banerjee
authors.affiliation: Leicester Royal Infirmary, University Hospitals of Leicester, Infirmary Square, Leicester, LE1 5WW, UK.
authors.forename: Theodoros
authors.initials: T
authors.lastname: Empeslidis
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D020533:Angiogenesis Inhibitors / Q000008:administration & dosage; D057915:Drug Substitution / Q000379:methods; D004361:Drug Tolerance; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008266:Macula Lutea / Q000473:pathology*; D008269:Macular Edema / Q000175:diagnosis / Q000188:drug therapy* / Q000209:etiology; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D000069579:Ranibizumab / Q000008:administration & dosage*; D040262:Receptors, Vascular Endothelial Growth Factor / Q000008:administration & dosage* / Q000037:antagonists & inhibitors; D011993:Recombinant Fusion Proteins / Q000008:administration & dosage*; D012170:Retinal Vein Occlusion / Q000150:complications* / Q000175:diagnosis / Q000188:drug therapy; D041623:Tomography, Optical Coherence; D016896:Treatment Outcome; D014792:Visual Acuity
chemical_list: D020533:Angiogenesis Inhibitors; D011993:Recombinant Fusion Proteins; C533178:aflibercept; D040262:Receptors, Vascular Endothelial Growth Factor; D000069579:Ranibizumab
keywords: Aflibercept; Anti-VEGF; CRVO; Ranibizumab; Switching