title: Correlation of Vascular Endothelial Growth Factor Production with Photochemical Reaction-induced Retinal Edema.
abstract: BACKGROUND
  Retinal edema is the major complication of retinal vein occlusion and diabetic retinopathy; it can damage visual function by influencing macular region. This study was to establish a rat retinal edema model and explore the related VEGF expression and observe the responses to anti-VEGF drugs in this model.
  
  
  METHODS
  A rat retinal edema model was established by inducing photochemical reaction using a 532 nm laser after the intravenous injection of Erythrosin B. Immediately after the laser treatment, models were given intravitreal injections of Ranibizumab or Conbercept to inhibit VEGF expression, and the changes of retinal thickness were measured. Retinal edema was observed using fundus photography (FP), optical coherence tomography (OCT), and fluoresce in fundus angiography (FFA) at 0, 1, 2, 4, 7 and 14 days after intervention. The retinal VEGF expression was measured using enzyme-linked immunosorbent assay (ELISA) and western blotting at each time point. The rat retinal edema model was also used to verify the function of anti-VEGF polypeptide ZY1.
  
  
  RESULTS
  Both retinal edema and vascular leakage were clearly observed at 1, 2 and 4 days after photochemical induction and the retinal thickness increased notably over the same period. The retinal VEGF expression peaked at day 1 and retina became thickening simultaneously. After the interventions, the VEGF expression of the Ranibizumab and Conbercept groups decreased at each time point compared to the edema group (26.90 ± 3.57 vs. 40.29 ± 6.68, F = 31.269 on day 1 and 22.36 ± 1.12 vs. 29.92 ± 0.93 F = 163.789 on day 2, both P < 0.01); the mean RT (278 ± 4 vs. 288 ± 3, F = 134.190 on day 1 and 274 ± 7 vs. 284 ± 6, F = 64.367 on day 2, both P < 0.05) and vascular leakage in these groups also decreased. The same results were observed in the ZY1 group, particularly at day 2 (P < 0.05).
  
  
  CONCLUSIONS
  This retinal edema model induced by a photochemical reaction is reliable and repeatable. Induced edema increases expression of VEGF. This model can be used to test new drugs.
authors.affiliation: Department of Ophthalmology, Shanghai General Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200080; Shanghai Key Laboratory of Fundus Disease, Shanghai General Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200080, China.
authors.forename: Liang
authors.initials: L
authors.lastname: Shan
authors.affiliation: Department of Ophthalmology, Fujian Provincial Hospital, Fuzhou, Fujian 350004, China.
authors.forename: Mi
authors.initials: M
authors.lastname: Zheng
authors.affiliation: Department of Ophthalmology, Shanghai General Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200080; Shanghai Key Laboratory of Fundus Disease, Shanghai General Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200080, China.
authors.forename: Yuan
authors.initials: Y
authors.lastname: Zhang
authors.affiliation: Department of Ophthalmology, Shanghai General Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200080, China.
authors.forename: Yuan
authors.initials: Y
authors.lastname: Qu
authors.affiliation: Department of Ophthalmology, Shanghai General Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200080; Shanghai Key Laboratory of Fundus Disease, Shanghai General Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200080, China.
authors.forename: Tian
authors.initials: T
authors.lastname: Niu
authors.affiliation: Shanghai Key Laboratory of Fundus Disease, Shanghai General Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200080, China.
authors.forename: Qing
authors.initials: Q
authors.lastname: Gu
authors.affiliation: Department of Ophthalmology, Shanghai General Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200080; Shanghai Key Laboratory of Fundus Disease, Shanghai General Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200080, China.
authors.forename: Kun
authors.initials: K
authors.lastname: Liu
authors.affiliation: Department of Ophthalmology, Shanghai General Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200080; Shanghai Key Laboratory of Fundus Disease, Shanghai General Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200080, China.
authors.forename: Xin
authors.initials: X
authors.lastname: Xia
mesh_terms: D020533:Angiogenesis Inhibitors / Q000627:therapeutic use; D000818:Animals; D004797:Enzyme-Linked Immunosorbent Assay; D004923:Erythrosine / Q000633:toxicity; D005451:Fluorescein Angiography; D058449:Intravitreal Injections; D008269:Macular Edema / Q000139:chemically induced / Q000188:drug therapy / Q000378:metabolism*; D000069579:Ranibizumab / Q000627:therapeutic use; D051381:Rats; D017207:Rats, Sprague-Dawley; D011993:Recombinant Fusion Proteins / Q000627:therapeutic use; D041623:Tomography, Optical Coherence; D042461:Vascular Endothelial Growth Factor A / Q000378:metabolism*
chemical_list: D020533:Angiogenesis Inhibitors; D011993:Recombinant Fusion Proteins; D042461:Vascular Endothelial Growth Factor A; C527363:KH902 fusion protein; D004923:Erythrosine; D000069579:Ranibizumab