Warfarin Resumption After Glaucoma Surgery
Resume warfarin within 24 hours after glaucoma repair surgery (typically the evening of surgery or the next morning) once adequate hemostasis is achieved, using the patient's usual maintenance dose. 1, 2
Timing of Resumption
Start warfarin 12-24 hours postoperatively when surgical site hemostasis is adequate, as early resumption (within 24 hours) is associated with significantly lower arterial thromboembolism rates (0.1%) compared to delayed resumption beyond 24 hours (2.4%). 1, 2
For most patients, this means resuming warfarin on the evening of the surgery day. 1
Understand that warfarin takes 2-3 days to achieve partial anticoagulant effect and 4-8 days for full therapeutic effect, so early resumption is critical to minimize the thrombotic gap. 1, 2
Dosing Strategy
Resume at the patient's usual maintenance dose—do not double the dose for the first 1-2 days, as this provides minimal benefit in reaching therapeutic INR faster and may increase bleeding risk. 1, 2
Doubling the warfarin dose achieves therapeutic INR only marginally faster (median 7.8 vs 9.0 days) and creates practical complications in patients with variable dosing regimens. 1
Delay Resumption If:
Inadequate surgical site hemostasis is present—this is the most critical factor determining when to restart. 1, 2
An anticipated need for additional surgical intervention exists. 1
The patient cannot take oral medications due to postoperative nausea or other factors. 1
For high bleeding risk situations (such as complex glaucoma procedures with anticipated prolonged wound healing), consider waiting 48-72 hours before resumption. 2
Special Considerations for Glaucoma Surgery
Minor ophthalmologic procedures, including many glaucoma surgeries, are generally considered low-to-moderate bleeding risk, and the American College of Chest Physicians suggests continuation of warfarin may even be considered for some minor eye procedures. 1
However, more complex retinal surgery or procedures with retrobulbar anesthesia may warrant warfarin interruption preoperatively and more cautious postoperative resumption. 1
Research in vitreoretinal surgery shows that patients can safely undergo eye surgery while maintaining therapeutic warfarin levels (INR 1.5-2.5), with postoperative hemorrhage rates of 7-16.7% that typically resolve spontaneously. 3, 4, 5
Warfarin continuation during vitreoretinal procedures shows no increase in intraoperative complications, though postoperative bleeding risk exists, particularly at higher INR levels (≥2.5). 3, 5, 6
Bridging Anticoagulation
Bridging with heparin or LMWH is generally NOT required for most patients undergoing glaucoma surgery, as the procedure is typically low-to-moderate bleeding risk. 2
Consider bridging only for very high thromboembolic risk patients (mechanical heart valves, recent stroke/TIA within 3 months, CHA₂DS₂-VASc score ≥7). 2
If bridging is used, wait at least 24 hours after surgery before starting LMWH for low-to-moderate bleeding risk procedures, or 48-72 hours for high bleeding risk procedures. 2
Common Pitfalls to Avoid
Do not unnecessarily delay warfarin resumption beyond 24 hours if hemostasis is adequate, as this substantially increases thrombotic risk (2.4% vs 0.1%). 1, 2
Do not double the warfarin dose when resuming—use the usual maintenance dose to avoid bleeding complications without meaningful benefit. 1, 2
Do not routinely give vitamin K if the preoperative INR is mildly elevated (1.5-1.9), as this may cause resistance to postoperative re-anticoagulation. 1
Ensure clear communication with the patient about when and how to resume warfarin, as lack of clear discharge instructions leads to medication errors and increased thrombotic risk. 2
Risk Stratification
Collaborate with the patient's cardiologist or primary care provider to assess individual thromboembolic risk versus bleeding risk, as management should account for the specific indication for anticoagulation. 7
Patients with atrial fibrillation, prosthetic heart valves, recent DVT/PE, or hypercoagulable states require particularly careful attention to minimizing the anticoagulation gap. 4
Consider modifying the surgical technique in high-risk bleeding patients (avoiding aggressive scleral dissection, using careful hemostasis techniques) rather than prolonging warfarin interruption. 7