title: Association of preoperative vitreous IL-8 and VEGF levels with visual acuity after vitrectomy in proliferative diabetic retinopathy.
abstract: OBJECTIVE
  To determine whether the vitreous levels of interleukin 8 (IL-8) and vascular endothelial growth factor (VEGF) of patients with proliferative diabetic retinopathy (PDR) were associated with poor visual acuity after vitrectomy.
  
  
  METHODS
  Observational cross-sectional study. Patient clinical characteristics and preoperative eye characteristics (63 eyes): visual acuity, iris neovascularization, vitreous haemorrhage, macular detachment, macular oedema, active retinal neovascularization, neovascularization of the disc, burned out PDR (defined as natural end stage of PDR with inactive membranes without previously performed laser photocoagulation) and panretinal photocoagulation were registered prior to vitrectomy for each patient. Vitreous VEGF and IL-8 levels were measured using the cytometric bead array method. Poor postoperative visual acuity was defined as visual acuity of <20/200 and was checked 2 years after vitrectomy.
  
  
  RESULTS
  Twenty-one of the 63 eyes (33.3%) had poor visual acuity after vitrectomy. Univariate analysis showed that vitreous levels of IL-8, the absence of panretinal photocoagulation, preoperative macular detachment and poor preoperative visual acuity were significantly associated with poor final visual acuity after vitrectomy. A stepwise multiple logistic regression analysis showed that elevated vitreous levels of IL-8 (p < 0.0001), macular detachment (p = 0.011) and the absence of panretinal photocoagulation (p = 0.03) were independent predictors for poor visual outcome.
  
  
  CONCLUSIONS
  Elevated vitreous IL-8 level could either be a marker of ischaemic inflammatory reaction, or it could play a role in deteriorating visual acuity by DR progression or both. Further studies are needed to provide better understanding of IL-8 and inflammation involvement in visual prognosis in PDR.
authors.affiliation: Eye Hospital, University Medical Centre Ljubljana, Ljubljana, Slovenia. mgpetrovic@yahoo.com
authors.forename: Mojca Globočnik
authors.initials: MG
authors.lastname: Petrovič
authors.forename: Peter
authors.initials: P
authors.lastname: Korošec
authors.forename: Mitja
authors.initials: M
authors.lastname: Košnik
authors.forename: Marko
authors.initials: M
authors.lastname: Hawlina
mesh_terms: D017668:Age of Onset; D000368:Aged; D000369:Aged, 80 and over; D003430:Cross-Sectional Studies; D003930:Diabetic Retinopathy / Q000378:metabolism* / Q000503:physiopathology / Q000601:surgery; D005260:Female; D005434:Flow Cytometry; D006442:Glycated Hemoglobin / Q000378:metabolism; D006801:Humans; D016209:Interleukin-8 / Q000378:metabolism*; D008297:Male; D008875:Middle Aged; D011184:Postoperative Period; D011300:Preoperative Care; D011446:Prospective Studies; D042461:Vascular Endothelial Growth Factor A / Q000378:metabolism*; D014792:Visual Acuity / Q000502:physiology*; D014821:Vitrectomy; D014822:Vitreous Body / Q000378:metabolism*
chemical_list: D006442:Glycated Hemoglobin; D016209:Interleukin-8; D042461:Vascular Endothelial Growth Factor A; C467484:VEGFA protein, human; C517652:hemoglobin A1c protein, human