title: The effects of aspirin and warfarin therapy on haemorrhage in vitreoretinal surgery.
abstract: BACKGROUND
  No substantial recommendations exist regarding the management of anticoagulant drugs prior to ocular surgery. Stopping anticoagulation can cause fatal emboli, but sight-threatening bleeds may occur if anticoagulation is continued. We examined the effects of anticoagulation on vitreoretinal surgery.
  
  
  METHODS
  Clinical details were prospectively entered on a database. The anticoagulant status of 541 consecutive patients undergoing vitreoretinal surgery was recorded.
  
  
  RESULTS
  Sixty patients in the study were taking aspirin and seven were taking warfarin. There were 11 cases of choroidal haemorrhage, one of which involved a warfarin user. Of 325 retinal detachment repairs, 21 (6.5%) had preoperative vitreous haemorrhages. Two of these patients were on aspirin and two were on warfarin. Sixty-six vitrectomies were performed for diabetic vitreous haemorrhages, of which nine re-bled postoperatively. One of these patients was taking warfarin. The association of warfarin with bleeding was statistically significant (relative risk 6.185).
  
  
  CONCLUSIONS
  Anticoagulation had no effect on the number of significant perioperative (choroidal) haemorrhages. Aspirin had little effect on bleeding during vitreoretinal surgery. Warfarin, however, was associated with bleeding complications. We suggest that aspirin should not be stopped prior to surgery. Warfarin may be stopped if the patient's thromboembolic risk is low.
authors.affiliation: Department of Ophthalmology, St Thomas' Hospital, Lambeth Palace Road, London SE1 7EH, UK.
authors.forename: Niro
authors.initials: N
authors.lastname: Narendran
authors.forename: Tom H
authors.initials: TH
authors.lastname: Williamson
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000925:Anticoagulants / Q000627:therapeutic use*; D001241:Aspirin / Q000627:therapeutic use*; D002648:Child; D002832:Choroid Hemorrhage / Q000139:chemically induced / Q000453:epidemiology*; D000075202:Contraindications; D005260:Female; D005343:Fibrinolytic Agents / Q000627:therapeutic use; D006801:Humans; D007431:Intraoperative Complications; D008297:Male; D008875:Middle Aged; D011183:Postoperative Complications; D012307:Risk Factors; D012591:Scleral Buckling; D006113:United Kingdom / Q000453:epidemiology; D014821:Vitrectomy; D014823:Vitreous Hemorrhage / Q000139:chemically induced / Q000453:epidemiology*; D014859:Warfarin / Q000627:therapeutic use*
chemical_list: D000925:Anticoagulants; D005343:Fibrinolytic Agents; D014859:Warfarin; D001241:Aspirin