title: Effect of combination therapy with bevacizumab and dexamethasone intravitreal implant in patients with retinal vein occlusion.
abstract: OBJECTIVE
  The objective of this study was to determine if dexamethasone intravitreal implant 0.7 mg (Ozurdex; Allergan, Inc) with bevacizumab (Avastin; Genentech, Inc) therapy can be synergistic, providing further improvements in visual acuity, sustainability, and macular thickness when compared with dexamethasone intravitreal implant 0.7 mg alone.
  
  
  METHODS
  This is a prospective, interventional case series intended to monitor changes in visual acuity and macular thickness in patients diagnosed with retinal vein occlusion (RVO), after injection of bevacizumab followed by a scheduled dexamethasone intravitreal implant. This study was designed to emulate patient care as received in the typical ophthalmology practice. Patients diagnosed with RVO, who were seen between September 2009 and July 2010, were included in this study if they had received previous anti-vascular endothelial growth factor therapy. Patients were included in analysis if the previous anti-vascular endothelial growth factor therapy was at least 6 weeks before and optical coherence tomography (OCT) was >300 μm on spectral-domain OCT. Exclusion criteria included history of vitrectomy, and/or rubeotic or advanced glaucoma. All patients were evaluated with Snellen visual acuity and measured for macular thickness (calculated by spectral-domain OCT) and intraocular pressure. At baseline, all patients were injected with bevacizumab, followed by dexamethasone intravitreal implant injection 2 weeks later. These patients were reexamined on a monthly basis and retreated when edema occurred.
  
  
  RESULTS
  The primary outcome measure was the time to reinjection based on OCT and vision criteria. The secondary outcomes were increases in visual acuity and the reduction of OCT thickness during that period. Thirty-four eyes of 33 patients, with a mean age of 72.8 years, were identified. Thirty-five percent were diagnosed with central RVO, while the other 65% were with branch RVO. Of these patients, 97% gained vision during the study. Mean visual acuity improved from initially 11 letters to a maximum of 25 letters during the study period. In addition, vision improved by at least 15 letters in 29% of patients initially up to 64% during the study period. Macular thickness decreased with the combination treatment by OCT, and the effect continued an average of 126 days from the initial bevacizumab treatment. Retreatment was unnecessary in 18% of the population during the 6-month study period.
  
  
  CONCLUSIONS
  This study demonstrates efficacy and the duration of effect using a combination of bevacizumab and dexamethasone versus dexamethasone alone. The combination is synergistic, increasing visual acuity and prolonging the time between injections, compared with either of these medications alone. Therefore, the combination of a vascular endothelial growth factor inhibitor and a dexamethasone implant may be a valuable option for RVO treatment.
authors.affiliation: Medical Center Ophthalmology Associates, San Antonio, Texas, USA. msinger1@earthlink.net
authors.forename: Michael A
authors.initials: MA
authors.lastname: Singer
authors.forename: Darren J
authors.initials: DJ
authors.lastname: Bell
authors.forename: Paul
authors.initials: P
authors.lastname: Woods
authors.forename: Joseph
authors.initials: J
authors.lastname: Pollard
authors.forename: Terry
authors.initials: T
authors.lastname: Boord
authors.forename: Angela
authors.initials: A
authors.lastname: Herro
authors.forename: Salman
authors.initials: S
authors.lastname: Porbandarwalla
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D020533:Angiogenesis Inhibitors / Q000627:therapeutic use*; D061067:Antibodies, Monoclonal, Humanized / Q000627:therapeutic use*; D000068258:Bevacizumab; D003907:Dexamethasone / Q000008:administration & dosage*; D004343:Drug Implants; D004359:Drug Therapy, Combination; D005260:Female; D005938:Glucocorticoids / Q000008:administration & dosage*; D006801:Humans; D058449:Intravitreal Injections; D008297:Male; D011446:Prospective Studies; D012170:Retinal Vein Occlusion / Q000175:diagnosis / Q000188:drug therapy* / Q000503:physiopathology; D019233:Retreatment; D041623:Tomography, Optical Coherence; D016896:Treatment Outcome; D042461:Vascular Endothelial Growth Factor A / Q000037:antagonists & inhibitors; D014792:Visual Acuity / Q000502:physiology; D014822:Vitreous Body / Q000187:drug effects
chemical_list: D020533:Angiogenesis Inhibitors; D061067:Antibodies, Monoclonal, Humanized; D004343:Drug Implants; D005938:Glucocorticoids; C467484:VEGFA protein, human; D042461:Vascular Endothelial Growth Factor A; D000068258:Bevacizumab; D003907:Dexamethasone