Sub-Tenon's anesthesia with aspirin, warfarin, and clopidogrel

To review the frequency of hemorrhagic complications with sub-Tenon's anesthesia in patients on aspirin, warfarin or clopidogrel.

St. James's University Hospital, Leeds, United Kingdom.

Data were collected prospectively for patients having elective phacoemulsification under sub-Tenon's anesthesia. Seventy-five patients were on aspirin, 65 were on warfarin, and 40 were on clopidogrel. Seventy-five patients on no anticoagulants were used as the control group. No changes in the anticoagulant regimen were made prior to surgery.

No sight-threatening hemorrhagic complications were noted, and no surgery was postponed or cancelled due to an anesthesic complication. Subconjunctival hemorrhage occurred in 19% in the control group, 40% in the clopidogrel group, 35% in the warfarin group, and 21% in the aspirin group. The warfarin and clopidogrel groups had the highest incidence of subconjunctival hemorrhage (P<.05). The incidence of hemorrhages involving more than 1 quadrant was highest in these 3 groups; however, this did not achieve statistical significance (P = .37, Fisher exact test).

Data from this study support the continued use of anticoagulant agents among routine users during cataract surgery using a sub-Tenon's block.