Anticoagulation therapy in glaucoma surgery

Abstract

Purpose

To identify the practices of ophthalmologists when undertaking glaucoma surgery on patients concurrently using warfarin or acetylsalicylic acid (aspirin).

Methods

A questionnaire was designed to examine perioperative management of patients being treated with warfarin and aspirin prior to and during glaucoma surgery. The questionnaire was posted with stamped self-addressed envelopes to all glaucoma specialists registered on a glaucoma shared care scheme database.

Results

Of the 93 eligible participants, 64 returned a completed questionnaire, representing a response rate of 68.8%. Twenty-one surgeons (32.8%) routinely stopped warfarin before surgery. Mean time prior to surgery of drug cessation was 4 days (range 2–7). Three surgeons (14.3%) routinely commenced heparin if they stopped warfarin. Ten (47.6%) never used heparin, while the remaining eight (38.1%) would use heparin depending upon the indication for anticoagulation. Forty-two surgeons (81.25%)were happy to operate only at an INR ≤3 at the time of surgery. The remainder (18.75%) were happy to operate at higher INRs, including two surgeons (3.1%) who would operate at any level. Twenty surgeons (31.2%) routinely stopped aspirin before surgery, while the rest did not. Of those who stopped aspirin, the mean time prior to surgery was 7.1 days (range 4–14 days).

Conclusions

The majority of surgeons do not stop warfarin or aspirin prior to glaucoma surgery. There is a great diversity in current practice with regard to the management of anticoagulant therapy prior to glaucoma surgery amongst glaucoma surgeons in England. Currently there is little information available to offer definitive guidance.

Appendix

Anticoagulation in glaucoma surgery questionnaire

Postcode of hospital (1st half): ________________

Q1: How many glaucoma surgeries do you perform per year?____________

__________ % Trabeculectomy ___________ % Non-penetrating

Q2: a) Do you routinely stop Warfarin treatment before trabeculectomy? Y / N

If so how far in advance? ________ days Why?______________

b) Do you liase with a haematologist about stopping Warfarin?

Y / N / Dependant on reason for Warfarin

Reasons warranting haematology consultation (please circle all that apply):

AF / DVT / PE / Porcine Heart Valve / Metal Heart Valve

c) Do you liase with the patients GP about stopping their Warfarin?

Y / N / Dependant on reason for Warfarin

Reasons warranting GP consultation (please circle all that apply):

AF / DVT / PE / Porcine Heart Valve / Metal Heart Valve

d) If you stop Warfarin do you use IV heparin instead?

Y / N / Dependant on reason for Warfarin (go to 2e)

e) What conditions do you consider warrant IV heparin instead of Warfarin?

AF / DVT / PE / Porcine Heart Valve / Metal Heart Valve

(please circle all that apply)

f) In patients on Warfarin (whether you’ve stopped it or not) when do you check the INR (please circle all that apply):

The day of operation / 1 week before / 2 weeks before

Q3: a) Do you routinely stop Aspirin before trabeculectomy? Y / N

If so how far in advance? ________ days Why? _______________

b) Do you liase with the patients GP about stopping their Aspirin?

Y / N / Dependant on reason for Aspirin (go to Q3c)

c) Reasons warranting GP consultation before stopping Aspirin:

AF / DVT / PE / History of CVA / History of TIA

IHD / History of MI

Q4: At what INR would you be unhappy proceeding to surgery (please circle)?

>1.0 >1.5 >2.0 >2.5 >3.0 >3.5 >4.0 Happy at any INR

Q5: a) Do you recall your last haemorrhagic complication following trabeculectomy?

Y / N / Never had a haemorrhagic complication

b) If so – was the patient on (please circle):

Warfarin / Aspirin / Both Aspirin and Warfarin / None /

Clopidogrel

c) If the patient was on Warfarin did you stop it pre-operatively Y / N

How many days pre-operatively? _________ days

Did you check the INR? Y / N When? ___ days pre-op

INR was ________ (approx figure fine – leave blank if cannot recall)

d) If the patient was on Aspirin did you stop it pre-operatively Y / N

How many days pre-operatively? _________ days

e) What was the complication (please circle all that apply):

Excessive Peroperative Haemorrhage

Post-operative Hyphaema

Post-op sub-conj Haemorrhage

Supra-Choroidal Haemorrhage

Bleed under flap or at ostium

Other:___________________________

f) How did you manage this complication?

Expectant / Active

Surgical revision / tPA injection / AC washout

Other: ________________________________________

Q6: a) Do you recall the last patient you operated upon on Warfarin? Y / N

b) Is this patient the same as the one described above? Y / N

If yes please skip this question (go to Q7)

c) Did you stop the Warfarin pre-operatively Y / N

d) If yes how many days pre-operatively? ________ days

e) Did you check the INR? Y / N

INR was ________ (approx) at time of surgery

f) Was there excessive bleeding per-operatively Y / N

g) Was there any post-operative haemorrhagic complication Y / N

If so what complication (please circle all that apply):

Excessive Peroperative Haemorrhage

Post-operative Hyphaema

Post-op sub-conj Haemorrhage

Supra-Choroidal Haemorrhage

Bleed under flap or at ostium

Other:________________

h) How did you manage this complication?

Expectant / Active

Surgical revision / tPA injection / AC washout

Other: ________________________________________

Q7: Have you carried out a trabeculectomy upon a patient on Clopidogrel?

Y (go to Q7a) / N (go to Q7b)

a) Did you stop the drug? Y / N

How long before surgery: _______ days

Was there excessive per-operative bleeding? Y / N

Were there any post-operative bleeding complications? Y / N

What was the complication: ________________________

b) If you operate on someone on Clopidogrel do you intend to stop the drug? Y / N

If so how long before surgery: _______ days

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