Managing ophthalmic surgery patients on antithrombotic drugs

Patients who undergo an ophthalmic procedure and are concomitantly taking antithrombotic drugs, i.e., antiplatelets and anticoagulants, during the perioperative period may require different management than patients not taking those drugs.

Investigators at St. Paul’s Eye Unit, Royal Liverpool University Hospital, Liverpool, UK, surveyed ophthalmologists regarding this scenario and reported that most physicians were comfortable with managing patients taking antiplatelets.

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However, the survey indicated that the situation was not so clear-cut when patients were taking warfarin and direct oral anticoagulants (DOACs). Makuloluwa et al. reported in Eye (2019; https://www.nature.com/articles/s41433-019-0382-6) that “…there was variability in managing patients on warfarin and DOACs.” A startling finding was that “40% [of ophthalmologists] were unaware of existing guidelines” for managing these patients.

The authors’ concerns regarding this matter are well-founded in that, for example, within the aging population, more patients are taking these drugs to prevent and treat cardiovascular and ischemic cerebral disease.

Importantly, the investigators also noted: “Continuing anti-thrombotic agents peri-operatively may increase the risk of potentially sight-threatening haemorrhagic complications, whereas discontinuing these medications may increase the risk of life-threatening thromboembolic events. Therefore, it is important to understand the indications of anti-thrombotic agents and when it may be safe to discontinue them peri-operatively.”

They also believed that it was important to stratify the ophthalmic surgeries depending on the risk of development of hemorrhagic complications during the perioperative period.

Based on these concerns, they conducted a PubMed search from January 2007 to August 2017 to identify articles that provided recommendations on managing antithrombic agents during the perioperative period of ophthalmic surgeries and reviewed the incidence rates of the associated hemorrhagic complications. They also reviewed all guidelines in the UK from the Royal College of Ophthalmologists and British Society of Haematology.

Study findings

The literature recommendations that all anti-thrombotic agents be continued for routine cataract surgeries that were performed under topical or sub-Tenon’s anesthesia.

For sharp-needle anesthesia, the literature recommended that surgeons avoid dual antiplatelet therapy and patients could continue taking warfarin if the International Normalized Ratio (INR) was within the therapeutic range.

For glaucoma surgery, the literature recommended that aspirin and clopidogrel be discontinued when the drugs are monotherapy for primary prevention, but they can be continued for secondary prevention of cardiovascular diseases. P2Y12 receptor inhibitors should be discontinued if used as dual antiplatelet therapy.

However, the risks and benefits of continuation of antiplatelet agents need special consideration in neovascular glaucoma and high IOP.

The investigators emphasized, “It is also important to consider and recognise that, intraoperative and post-operative haemorrhagic complications in glaucoma, especially if sustained or prolonged, can cause severe visual loss due to high pressure in already compromised optic nerves. Anticoagulants should be discontinued with consideration for bridging therapy depending on patient’s risk factors.”

For vitreoretinal surgery, the literature results were considered controversial.

“The recommendations for peri-operative management is [sic] similar to that for glaucoma surgery. Anti-thrombotic agents are to be discontinued where possible and to be cautious of these agents in the presence of neovascular retinal diseases,” the study reported.

For oculoplastic and lacrimal surgery, procedures that are carried out posterior to the orbital septum and deep orbital surgery are associated with potentially sight-threatening hemorrhagic complications, and lacrimal surgery also is considered a high-risk procedure. Procedures that are performed anterior to the orbital septum are considered low risk.

The authors stated: “Expert groups on oculoplastic surgery recommend stopping anti-thrombotic agents during blepharoplasty, lacrimal surgery and deep orbital surgery as these are considered high risk for sight-threatening haemorrhagic complications.”

For strabismus surgery, the recommendations are similar to those for glaucoma and vitreoretinal surgeries.

For corneal surgery, no evidence was found.

Hemorrhagic complications were reported in all groups.

Study recommendations

The authors proposed their pathway for managing patients taking antithrombotic drugs.

For low-risk procedures (sub-Tenon/topical cataract, corneal, chalazion, eyelid cyst/lesion removal, and strabismus surgeries), antiplatelets can be continued. For anticoagulants, the INR should be check on the surgical day and warfarin continued if within the therapeutic range; the DOAC dose is stopped 2 days preoperatively (depending on renal function) and restarted 1-2 days postoperatively if adequate hemostasis is achieved.

For high-risk procedures (peri/retrobulbar anesthesia, glaucoma, vitreoretinal (pars plana vitrectomy), vitreoretinal procedures [oncology: endoresection, biopsy of intraocular tumors, plaques/markers], oculoplastics [blepharoplasty, post-septal eyelid surgery], and temporal artery biopsy surgeries], antiplatelets are stopped 7 days preoperatively but continued in high-risk patients.

Prasugrel, a platelet-aggregation inhibitor [Effent in the US; Efent in the European Union] is stopped 7 days preoperatively, and Ticagrelor, [a platelet-aggregation inhibitor] 5 days preoperatively. For the anticoagulants (warfarin), the local anticoagulant service should be informed at the time of listing. If low risk (e.g., non-valvular atrial fibrillation), warfarin should be stopped 2 days preoperatively, the INR is checked on the surgical day, and continued if <2. Re-start on evening of surgery. If high risk, discuss with physician. For the DOACs, the recommended action is the same as for low-risk procedures.

In conclusion, the authors emphasized the importance of considering the indications for anti-thrombotic agents and the risk of thromboembolic events and hemorrhagic complications depending on the patient and surgery. Bridging anticoagulation should be considered when oral anticoagulants are discontinued.

“The most appropriate surgical procedure should be offered to the patient depending on the risk of haemorrhage perioperatively when anti-thrombotic agents are continued. When urgent surgery is required or when a patient’s case is complex, it is important to take a multidisciplinary approach to the perioperative management of anti-thrombotic agents,” they said.