title: Vascular endothelial growth factor is a critical stimulus for diabetic macular edema.
abstract: OBJECTIVE
  The role of vascular endothelial growth factor (VEGF) in diabetic macular edema (DME) was tested with ranibizumab, a specific antagonist of VEGF.
  
  
  METHODS
  A nonrandomized clinical trial.
  
  
  METHODS
  Ten patients with chronic DME received intraocular injections of 0.5 mg of ranibizumab at baseline and at one, two, four, and six months. The primary outcome was change in foveal thickness between baseline and seven months, and the secondary outcome measures were changes from baseline in visual acuity and macular volume.
  
  
  RESULTS
  Mean values at baseline were 503 microm for foveal thickness, 9.22 mm3 for macular volume, and 28.1 letters (20/80) read on an Early Treatment Diabetic Retinopathy Study (ETDRS) visual acuity chart. At seven months (one month after the fifth injection), the mean foveal thickness was 257 microm, which was a reduction of 246 microm (85% of the excess foveal thickness present at baseline; P = .005 by Wilcoxon signed-rank test for likelihood that this change is due to ranibizumab rather than chance). The macular volume was 7.47 mm3, which was a reduction of 1.75 mm3 (77% of the excess macular volume at baseline; P = .009). Mean visual acuity was 40.4 letters (20/40), which was an improvement of 12.3 letters (P = .005). The injections were well-tolerated with no ocular or systemic adverse events.
  
  
  CONCLUSIONS
  Intraocular injections of ranibizumab significantly reduced foveal thickness and improved visual acuity in 10 patients with DME, which demonstrated that VEGF is an important therapeutic target for DME. A randomized, controlled, double-masked trial is needed to test whether intraocular injections of ranibizumab provide long-term benefit to patients with DME.
authors.affiliation: The Wilmer Eye Institute, The Johns Hopkins University School of Medicine, Baltimore, Maryland 21287-9277, USA.
authors.forename: Quan Dong
authors.initials: QD
authors.lastname: Nguyen
authors.forename: Sinan
authors.initials: S
authors.lastname: Tatlipinar
authors.forename: Syed Mahmood
authors.initials: SM
authors.lastname: Shah
authors.forename: Julia A
authors.initials: JA
authors.lastname: Haller
authors.forename: Edward
authors.initials: E
authors.lastname: Quinlan
authors.forename: Jennifer
authors.initials: J
authors.lastname: Sung
authors.forename: Ingrid
authors.initials: I
authors.lastname: Zimmer-Galler
authors.forename: Diana V
authors.initials: DV
authors.lastname: Do
authors.forename: Peter A
authors.initials: PA
authors.lastname: Campochiaro
mesh_terms: D000911:Antibodies, Monoclonal / Q000008:administration & dosage; D061067:Antibodies, Monoclonal, Humanized; D002908:Chronic Disease; D003930:Diabetic Retinopathy / Q000175:diagnosis / Q000188:drug therapy / Q000378:metabolism*; D005260:Female; D005584:Fovea Centralis / Q000187:drug effects / Q000473:pathology; D006801:Humans; D007267:Injections; D008269:Macular Edema / Q000175:diagnosis / Q000188:drug therapy / Q000378:metabolism*; D008297:Male; D008875:Middle Aged; D000069579:Ranibizumab; D041623:Tomography, Optical Coherence; D042461:Vascular Endothelial Growth Factor A / Q000037:antagonists & inhibitors / Q000502:physiology*; D014792:Visual Acuity / Q000187:drug effects / Q000502:physiology; D014822:Vitreous Body
chemical_list: D000911:Antibodies, Monoclonal; D061067:Antibodies, Monoclonal, Humanized; C467484:VEGFA protein, human; D042461:Vascular Endothelial Growth Factor A; D000069579:Ranibizumab