title: Anti-VEGF-refractory exudative age-related macular degeneration: differential response according to features on optical coherence tomography.
abstract: OBJECTIVE
  To describe optical coherence tomography (OCT) characteristics of neovascular age-related macular degeneration (AMD) patients refractory to intravitreal anti-vascular endothelial growth factor (VEGF) injections (ranibizumab, bevacizumab) and their responses to alternative anti-VEGF agents or photodynamic therapy (PDT).
  
  
  METHODS
  A retrospective review of 267 neovascular AMD patients treated with intravitreal anti-VEGF injections.
  
  
  RESULTS
  Twenty patients (7.5%) were refractory to anti-VEGF injections (stationary or increased retinal exudation despite three or more monthly injections). They were grouped into either the extensive intraretinal fluid group (IRF group, 9 patients) or the subretinal fluid only group (SRF group, 11 patients) according to OCT findings. In the IRF group, response rates to subsequent treatment were 0% (0 / 7) for bevacizumab, 50% (3 / 6) for ranibizumab and 50% (3 / 6) for PDT ± anti-VEGF. Three out of four bevacizumab-refractory patients showed response to ranibizumab as a secondary treatment. In the SRF group, response rates were lower with 0% (0 / 7) for bevacizumab, 22.2% (2 / 9) for ranibizumab and 28.6% (2 / 7) for PDT ± anti-VEGF. One out of four bevacizumab-refractory patients responded to ranibizumab. The visual outcome was worse in the IRF group (median 20 / 1,000) than in the SRF group (median 20 / 100).
  
  
  CONCLUSIONS
  In anti-VEGF-refractory neovascular AMD, patients with extensive IRF refractory to bevacizumab can be responsive to ranibizumab while patients with SRF may be refractory to both, suggesting a different pathophysiology and intraocular pharmacokinetics.
authors: Department of Ophthalmology, Seoul National University Bundang Hospital, Seoul National University College of Medicine, Seongnam, Korea.
authors: Joo Young
authors: JY
authors: Shin
authors: Se Joon
authors: SJ
authors: Woo
authors: Jeeyun
authors: J
authors: Ahn
authors: Kyu Hyung
authors: KH
authors: Park
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D020533:Angiogenesis Inhibitors / Q000008:administration & dosage; D061067:Antibodies, Monoclonal, Humanized / Q000008:administration & dosage*; D000068258:Bevacizumab; D005260:Female; D005451:Fluorescein Angiography; D005500:Follow-Up Studies; D005654:Fundus Oculi; D006801:Humans; D058449:Intravitreal Injections; D008297:Male; D008875:Middle Aged; D000069579:Ranibizumab; D012189:Retrospective Studies; D041623:Tomography, Optical Coherence / Q000379:methods*; D016896:Treatment Outcome; D042461:Vascular Endothelial Growth Factor A / Q000037:antagonists & inhibitors*; D014792:Visual Acuity; D057135:Wet Macular Degeneration / Q000188:drug therapy* / Q000378:metabolism / Q000473:pathology
chemical_list: D020533:Angiogenesis Inhibitors; D061067:Antibodies, Monoclonal, Humanized; D042461:Vascular Endothelial Growth Factor A; D000068258:Bevacizumab; D000069579:Ranibizumab
keywords: Bevacizumab; Drug resistance; Macular degeneration; Optical coherence tomography; Ranibizumab