title: Intravitreal levels of vascular endothelial growth factor and interleukin-6 are correlated with macular edema in branch retinal vein occlusion.
abstract: BACKGROUND
  To investigate whether vascular endothelial growth factor (VEGF) or interleukin-6 (IL-6) contributes to the pathogenesis of macular edema in eyes with branch retinal vein occlusion (BRVO), the correlations between these factors were investigated.
  
  
  METHODS
  We studied 25 patients suffering from macular edema with BRVO and 14 patients with nonischemic ocular disease (control group). The degree of retinal ischemia was evaluated in terms of the area of capillary nonperfusion using Scion Images, and the severity of macular edema was examined using optical coherence tomography. Vitreous fluid samples were obtained at the time of vitreoretinal surgery, and VEGF and IL-6 levels in the vitreous fluid and plasma were determined by means of enzyme-linked immunosorbent assays.
  
  
  RESULTS
  Vitreous fluid levels of VEGF and IL-6 were significantly elevated in patients with BRVO compared with control patients (P = 0.0011 and P < 0.0001, respectively). Also, the vitreous level of VEGF was significantly correlated with that of IL-6 (P = 0.0012), and vitreous levels of VEGF and IL-6 were correlated with the size of the BRVO nonperfusion area (P < 0.0001 and P = 0.0033, respectively). Furthermore, vitreous levels of VEGF and IL-6 were correlated with the severity of macular edema (P = 0.0008 and P = 0.0191, respectively) and the severity of macular edema of BRVO was significantly correlated with the size of the BRVO nonperfusion area (P=0.0044).
  
  
  CONCLUSIONS
  The levels of VEGF and IL-6 are increased in patients with macular edema with BRVO and are significantly correlated with the size of the nonperfusion area and the severity of macular edema. Therefore, they may play a role in macular edema with BRVO.
authors.affiliation: Department of Ophthalmology and Visual Science, Graduate School of Biomedical Sciences, Hiroshima University, 1-2-3, Kasumi-cho, Minami-ku, Hiroshima, 734-8551, Japan.
authors.forename: Hidetaka
authors.initials: H
authors.lastname: Noma
authors.forename: Atsushi
authors.initials: A
authors.lastname: Minamoto
authors.forename: Hideharu
authors.initials: H
authors.lastname: Funatsu
authors.forename: Hidetoshi
authors.initials: H
authors.lastname: Tsukamoto
authors.forename: Kensuke
authors.initials: K
authors.lastname: Nakano
authors.forename: Hidetoshi
authors.initials: H
authors.lastname: Yamashita
authors.forename: Hiromu K
authors.initials: HK
authors.lastname: Mishima
mesh_terms: D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D006801:Humans; D015850:Interleukin-6 / Q000378:metabolism*; D008269:Macular Edema / Q000209:etiology / Q000378:metabolism*; D008297:Male; D008875:Middle Aged; D012170:Retinal Vein Occlusion / Q000150:complications / Q000378:metabolism*; D042461:Vascular Endothelial Growth Factor A / Q000378:metabolism*; D014822:Vitreous Body / Q000378:metabolism*
chemical_list: D015850:Interleukin-6; C467484:VEGFA protein, human; D042461:Vascular Endothelial Growth Factor A