title: Elevated vitreous nitric oxide levels in patients with proliferative diabetic retinopathy.
abstract: OBJECTIVE
  The aim of this study was to determine nitric oxide levels in the vitreous of patients with proliferative diabetic retinopathy.
  
  
  METHODS
  Using the spectrophotometric method based on Griess reaction, we measured levels of nitrite, the stable product of nitric oxide, in the vitreous of 21 eyes of 21 patients who underwent vitrectomy for the treatment of proliferative diabetic retinopathy with tractional retinal detachment, prospectively. Three samples were excluded from the study because of blood contamination. The control group was made up of vitreous samples from 15 eyes of 15 normal cadavers and five eyes of five patients who were undergoing vitrectomy for macular hole surgery.
  
  
  RESULTS
  Nitrite levels were 0. 524 +/- 0.27 microM and 0.383 +/- 0.17 microM in the vitreous of patients with proliferative diabetic retinopathy of diabetes type I and type II, respectively. In 15 cadaver eyes and five vitreous samples from patients who underwent macular hole surgery, nitrite levels were below the detection limit (less than 0.08 microM). There was no significant difference between nitrite levels in patients with type I and type II diabetes (P =.56), whereas there was a significant difference between diabetes groups and controls (P <. 00001).
  
  
  CONCLUSIONS
  Vitreous nitric oxide levels are elevated in patients with proliferative diabetic retinopathy with tractional retinal detachment. Nitric oxide may play a role in the pathogenesis of proliferative diabetic retinopathy.
authors.affiliation: Department of Ophthalmology, Baskent University School of Medicine, Ankara, Turkey. gurselyilmaz@hotmail.com
authors.forename: G
authors.initials: G
authors.lastname: Yilmaz
authors.forename: P
authors.initials: P
authors.lastname: Esser
authors.forename: N
authors.initials: N
authors.lastname: Kociok
authors.forename: P
authors.initials: P
authors.lastname: Aydin
authors.forename: K
authors.initials: K
authors.lastname: Heimann
authors.forename: N
authors.initials: N
authors.lastname: Kociek
mesh_terms: D000328:Adult; D003922:Diabetes Mellitus, Type 1 / Q000150:complications / Q000378:metabolism; D003924:Diabetes Mellitus, Type 2 / Q000150:complications / Q000378:metabolism; D003930:Diabetic Retinopathy / Q000150:complications / Q000378:metabolism* / Q000601:surgery; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009569:Nitric Oxide / Q000378:metabolism*; D012163:Retinal Detachment / Q000209:etiology / Q000378:metabolism / Q000601:surgery; D014821:Vitrectomy; D014822:Vitreous Body / Q000378:metabolism*
chemical_list: D009569:Nitric Oxide