title: Central and hemicentral retinal vein occlusion: role of anti-platelet aggregation agents and anticoagulants.
abstract: OBJECTIVE
  To investigate systematically the role of anti-platelet-aggregating drugs or anticoagulants in central retinal vein occlusion (CRVO) and hemi-CRVO.
  
  
  METHODS
  Cohort study.
  
  
  METHODS
  Six hundred eighty-six consecutive patients with CRVO (567 patients, 585 eyes) and nonischemic hemi-CRVO (119 patients, 122 eyes).
  
  
  METHODS
  At first visit, all patients had a detailed ophthalmic and medical history (including the use of anti-platelet aggregating drugs or anticoagulants), and comprehensive ophthalmic and retinal evaluation. Visual evaluation was carried out by recording visual acuity, using the Snellen visual acuity chart, and visual fields with a Goldmann perimeter. The same ophthalmic evaluation was performed at each follow-up visit. At the initial visit, CRVO and hemi-CRVO were classified as nonischemic and ischemic.
  
  
  METHODS
  Visual acuity, visual fields, and severity of retinal hemorrhages.
  
  
  RESULTS
  All 3 types of CRVO, showed a significantly greater severity of retinal hemorrhages among aspirin users than nonusers (P<0.001). Initial visual acuity and visual fields were significantly worse in aspirin users than nonusers in nonischemic CRVO and hemi-CRVO, but did not differ for ischemic CRVO. Among patients with nonischemic CRVO who initially had 20/60 or better visual acuity, there was a significant association of aspirin use with visual acuity deterioration. The odds ratio of visual acuity deterioration, adjusting for age, diabetes, ischemic heart disease, and hypertension, for aspirin users relative to nonusers was 2.24 (95% confidence interval [CI], 1.14-4.41; P = 0.020). Of those whose macular edema resolved, overall cumulative visual acuity outcome also suggested a higher percentage with deterioration among aspirin users, odds ratio for deterioration of 3.62 (95% CI, 0.97-13.54; P = 0.05) for aspirin users relative to nonusers. For the nonischemic CRVO patients with 20/70 or worse visual acuity at the initial visit, after resolution of macular edema, improvement in visual acuity was less likely in the aspirin users than in nonusers (odds ratio, 0.18; 95% CI, 0.04-0.72; P = 0.016).
  
  
  CONCLUSIONS
  Findings of this study indicate that, for patients with CRVO and hemi-CRVO, the use of aspirin, other anti-platelet aggregating agents, or anticoagulants was associated with a worse visual outcome and no apparent benefit.
  
  
  BACKGROUND
  The author(s) have no proprietary or commercial interest in any materials discussed in this article.
authors.affiliation: Department of Ophthalmology and Visual Sciences, College of Medicine, University of Iowa, Iowa City, Iowa. sohan-hayreh@uiowa.edu
authors.forename: Sohan Singh
authors.initials: SS
authors.lastname: Hayreh
authors.forename: Patricia A
authors.initials: PA
authors.lastname: Podhajsky
authors.forename: M Bridget
authors.initials: MB
authors.lastname: Zimmerman
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000925:Anticoagulants / Q000627:therapeutic use*; D001241:Aspirin / Q000627:therapeutic use; D015331:Cohort Studies; D004176:Dipyridamole / Q000627:therapeutic use; D005260:Female; D006801:Humans; D008269:Macular Edema / Q000503:physiopathology; D008297:Male; D008875:Middle Aged; D010975:Platelet Aggregation Inhibitors / Q000627:therapeutic use*; D011446:Prospective Studies; D012166:Retinal Hemorrhage / Q000503:physiopathology; D012170:Retinal Vein Occlusion / Q000188:drug therapy* / Q000503:physiopathology; D016896:Treatment Outcome; D014792:Visual Acuity / Q000502:physiology; D058609:Visual Field Tests; D014794:Visual Fields / Q000502:physiology; D014859:Warfarin / Q000627:therapeutic use; D055815:Young Adult
chemical_list: D000925:Anticoagulants; D010975:Platelet Aggregation Inhibitors; D014859:Warfarin; D004176:Dipyridamole; D001241:Aspirin