None of the Listed Medications Are Blood Thinners That Require Discontinuation Before Eye Shunt Surgery
None of the medications on this list have anticoagulant or antiplatelet properties that would necessitate preoperative discontinuation for an ocular shunt procedure. The medications listed are exclusively glaucoma therapies (carbonic anhydrase inhibitors, alpha-agonists, beta-blockers, prostaglandin analogs, and rho kinase inhibitors), one thyroid medication (methimazole), topical antibiotics, topical NSAIDs, and topical corticosteroids—none of which affect systemic hemostasis 1, 2.
Why These Medications Can Be Continued
Glaucoma Medications Have No Antiplatelet or Anticoagulant Effects
Acetazolamide is a systemic carbonic anhydrase inhibitor used to lower intraocular pressure; it does not affect platelet function or coagulation 3, 4.
Topical carbonic anhydrase inhibitors (dorzolamide, brinzolamide in Simbrinza) work locally in the eye to reduce aqueous humor production without systemic hemostatic effects 5, 6, 4.
Alpha-2 agonists (brimonidine in Combigan, Simbrinza, and Rocklatan) reduce aqueous production and increase uveoscleral outflow but have no antiplatelet activity 5, 4, 7.
Beta-blockers (timolol in Combigan and as standalone timolol maleate) lower intraocular pressure by decreasing aqueous humor production; they do not impair hemostasis 3, 7, 8.
Prostaglandin analogs (latanoprost in Rocklatan, latanoprostene bunod in Vyzulta) increase uveoscleral outflow without affecting coagulation 9, 3.
Rho kinase inhibitors (netarsudil in Rhopressa and Rocklatan) lower intraocular pressure through trabecular meshwork and episcleral venous pressure effects, not through anticoagulation 9.
Pilocarpine is a cholinergic miotic that increases aqueous outflow through the trabecular meshwork without hemostatic effects.
Other Medications Also Lack Anticoagulant Properties
Ketorolac 0.5% eye drops is a topical NSAID used perioperatively to control inflammation and pain; systemic absorption from ophthalmic administration is negligible and does not produce clinically significant antiplatelet effects 1, 2.
Prednisolone acetate 1% is a topical corticosteroid for ocular inflammation; it does not affect coagulation 1, 2.
Ofloxacin 0.3% is a topical fluoroquinolone antibiotic with no hemostatic impact 1, 2.
Methimazole is an antithyroid medication that inhibits thyroid hormone synthesis; it has no anticoagulant or antiplatelet properties 1, 2.
Guideline Context for Ophthalmic Procedures
Minor Eye Procedures and Antiplatelet Therapy
The American College of Chest Physicians (2022) and Canadian Cardiovascular Society (2011) guidelines specifically address minor ophthalmic procedures (such as cataract surgery) and recommend continuing antiplatelet drugs (aspirin, clopidogrel) throughout the perioperative period because the bleeding risk is low 1, 2, 10.
For patients actually taking aspirin or P2Y12 inhibitors undergoing minor ophthalmologic procedures, guidelines suggest continuation rather than interruption [10, @43@].
Glaucoma shunt surgery (trabeculectomy, tube shunt) carries a higher bleeding risk than cataract surgery, but the guidelines still emphasize that only systemic anticoagulants and antiplatelet agents require consideration for interruption—not topical ophthalmic medications 1, 2.
What Actually Requires Preoperative Management
Aspirin may be continued for most ophthalmic procedures; interruption 7–10 days before surgery is reserved for high-bleeding-risk procedures such as intracranial or spinal surgery 11, 1, 12, 2.
Clopidogrel and other P2Y12 inhibitors should be stopped 5–7 days before major bleeding-risk surgery unless the patient has a recent coronary stent (bare-metal stent <6 weeks, drug-eluting stent <12 months), in which case dual antiplatelet therapy should be continued 11, 1, 13.
Warfarin is typically interrupted 5 days before surgery with bridging anticoagulation considered for high-thrombotic-risk patients 2.
Direct oral anticoagulants (DOACs) such as dabigatran, rivaroxaban, and apixaban require interruption 3–5 days before major surgery depending on renal function 12, 10.
Common Pitfalls to Avoid
Do not confuse topical ophthalmic NSAIDs (ketorolac eye drops) with systemic NSAIDs or aspirin. Topical ketorolac has negligible systemic absorption and does not produce clinically meaningful antiplatelet effects 1, 2.
Do not discontinue glaucoma medications before ocular surgery unless specifically instructed by the ophthalmologist for surgical technique reasons (e.g., stopping miotics like pilocarpine to allow pupil dilation). These medications do not affect bleeding risk 1, 2.
Coordinate with the patient's cardiologist if the patient were actually taking systemic antiplatelet or anticoagulant therapy not listed here, especially in the context of recent coronary stents or high thrombotic risk 11, 1, 13.
Ensure the surgical team is aware of all medications, but recognize that the medications on this list pose no hemostatic concern for glaucoma shunt placement 1, 2.