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The effects of aspirin and warfarin therapy on haemorrhage in vitreoretinal surgery.

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).


CONCLUSION
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.