title: Plasma homocysteine and cysteine levels in retinal vein occlusion.
abstract: OBJECTIVE
  To determine plasma homocysteine and cysteine levels in patients with retinal vein occlusion (RVO) and in healthy subjects and to ascertain whether there are statistically significant differences between patients and control subjects.
  
  
  METHODS
  In this case-control study, the study group consisted of 75 consecutive patients with RVO: 33 had central retinal vein occlusion (CRVO), and 42 had branch retinal vein occlusion (BRVO). Seventy-two apparently healthy age- and sex-matched subjects served as control subjects. Homocysteine and cysteine levels were measured with a new laser-induced fluorescence capillary electrophoresis (CE-LIF) METHOD: Wilcoxon or Student's t-test was used, when appropriate, to determine differences between groups.
  
  
  RESULTS
  There were no significant differences in median plasma homocysteine between patients with RVO and control subjects, nor were there any statistically significant differences when patients were categorized by type of vein occlusion (CRVO or BRVO). Similarly, there were no significant differences in mean plasma cysteine between patients with RVO and control subjects. However, when categorized by type of vein occlusion, mean plasma cysteine was significantly higher in CRVO patients than in control subjects (P = 0.034).
  
  
  CONCLUSIONS
  This study failed to demonstrate an association between increased plasma homocysteine and RVO. Mean plasma cysteine was significantly higher in patients with CRVO, suggesting that hypercysteinemia may contribute to the pathogenesis of this retinal vascular disorder.
authors.affiliation: Institute of Ophthalmology, University of Sassari, Sassari, Italy. apinna@uniss.it
authors.forename: Antonio
authors.initials: A
authors.lastname: Pinna
authors.forename: Ciriaco
authors.initials: C
authors.lastname: Carru
authors.forename: Angelo
authors.initials: A
authors.lastname: Zinellu
authors.forename: Stefano
authors.initials: S
authors.lastname: Dore
authors.forename: Luca
authors.initials: L
authors.lastname: Deiana
authors.forename: Francesco
authors.initials: F
authors.lastname: Carta
mesh_terms: D000368:Aged; D016022:Case-Control Studies; D003545:Cysteine / Q000097:blood*; D019075:Electrophoresis, Capillary / Q000379:methods; D005260:Female; D006710:Homocysteine / Q000097:blood*; D006801:Humans; D008297:Male; D008875:Middle Aged; D012170:Retinal Vein Occlusion / Q000097:blood*
chemical_list: D006710:Homocysteine; D003545:Cysteine