title: The effect of unilateral intravitreal bevacizumab (avastin), in the treatment of diffuse bilateral diabetic macular edema: a pilot study.
abstract: OBJECTIVE
  To investigate whether there are systemic effects of unilateral intravitreal administration of bevacizumab on the untreated eye.
  
  
  METHODS
  Twenty-three consecutive patients were enrolled in this study. All patients had a clinical diagnosis of bilateral diffuse diabetic macular edema with a central retinal thickness greater than 275 microm by Optical Coherence Tomography. They were treated with 2.5 mg bevacizumab intravitreally in the worst eye based on lines of vision, number of Early Treatment Diabetic Retinopathy Study letters, and central retinal thickness. The patients were observed every 2 weeks for 4 weeks. The Best Corrected Visual Acuity, central retinal thickness (microm), and macular volume (mm) in the untreated eye measured by Optical Coherence Tomography were recorded at every visit.
  
  
  RESULTS
  The Best Corrected Visual Acuity (mean +/- SD) in the untreated eye was 34.46 +/- 17.29. Early Treatment Diabetic Retinopathy Study letters at baseline, 38.31 +/- 14.64 at 2 weeks, and 37.38 +/- 14.59 at 4 weeks. The central retinal thickness in the untreated eye was 324.77 +/- 76.51 microm at baseline, 319 +/- 75.7 microm at 2 weeks, and 315.54 +/- 78.2 microm at 4 weeks. The macular volume in the untreated eye was 8.99 +/- 1.2 mm at baseline, 9.16 +/- 1.26 mm at 2 weeks, and 8.99 +/- 1.09 mm at 4 weeks. There were no statistically significant differences between any of the measurements.
  
  
  CONCLUSIONS
  Due to the lack of significant changes in the measurements of the untreated eye, the systemic effect of intravitreal bevacizumab seems to be unlikely. The small sample and low confidence of this pilot study prevent us to draw concrete conclusions.
authors.affiliation: Retina Department, Asociación Para Evitar la Ceguera en México. rvelezmx@yahoo.com
authors.forename: Raul
authors.initials: R
authors.lastname: Velez-Montoya
authors.forename: Jans
authors.initials: J
authors.lastname: Fromow-Guerra
authors.forename: Octavio
authors.initials: O
authors.lastname: Burgos
authors.forename: Maurice B
authors.initials: MB
authors.lastname: Landers
authors.forename: Virgilio
authors.initials: V
authors.lastname: Morales-Catón
authors.forename: Hugo
authors.initials: H
authors.lastname: Quiroz-Mercado
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D020533:Angiogenesis Inhibitors / Q000627:therapeutic use*; D000911:Antibodies, Monoclonal / Q000627:therapeutic use*; D061067:Antibodies, Monoclonal, Humanized; D000068258:Bevacizumab; D003930:Diabetic Retinopathy / Q000188:drug therapy*; D005260:Female; D007839:Functional Laterality; D006801:Humans; D007267:Injections; D008269:Macular Edema / Q000188:drug therapy*; D008297:Male; D008875:Middle Aged; D010865:Pilot Projects; D012160:Retina / Q000473:pathology; D041623:Tomography, Optical Coherence; D016896:Treatment Outcome; D042461:Vascular Endothelial Growth Factor A / Q000037:antagonists & inhibitors; D014792:Visual Acuity / Q000502:physiology; D014822:Vitreous Body
chemical_list: D020533:Angiogenesis Inhibitors; D000911:Antibodies, Monoclonal; D061067:Antibodies, Monoclonal, Humanized; D042461:Vascular Endothelial Growth Factor A; D000068258:Bevacizumab