Management of antithrombotic therapy in gonioscopy-assisted transluminal trabeculotomy

Dear Editor,

The use of minimally invasive glaucoma surgery (MIGS) techniques is becoming increasingly widespread in the management of glaucoma, with reported outcomes indicating acceptable success rates and fewer potential side effects. The frequency of glaucoma rises with age, and this advancing age may lead to the onset of systemic diseases and the need for anticoagulant and antiplatelet medications. For this reason, while managing glaucoma with current surgical procedures, glaucoma surgeons also have to manage patients’ systemic diseases and the treatments associated with them. The fact that antithrombotic drugs are initiated for different indications, have various mechanisms of action, and require constant updating due to the introduction of new molecules can create challenges for ophthalmologists. The aim of this letter is to highlight recommendations regarding the management of patients’ blood-thinning medications prior to gonioscopy-assisted transluminal trabeculotomy (GATT) surgery.

While guidelines provide recommendations on the perioperative management of anticoagulant and antiplatelet medications for various types of surgeries, there are no standardized protocols specifically for ophthalmologic surgeries. In general, anterior segment surgeries are considered low-risk in terms of bleeding, whereas posterior segment surgeries and those performed under retrobulbar anesthesia are regarded as having a moderate to high risk of bleeding.[1] While there is a consensus on the management of antithrombotic therapy during cataract surgery, scientific evidence on its management in glaucoma surgery is limited. The available studies primarily focus on two classical surgical procedures: Trabeculectomy and the implantation of drainage devices. The sudden changes in intraocular pressure that may occur during these surgeries, particularly in the presence of anticoagulant therapy, can increase the risk of bleeding complications such as hyphema, intra-bleb bleeding, and suprachoroidal hemorrhage. Furthermore, the proinflammatory response triggered by bleeding may adversely affect surgical success.[2] GATT differs from classical glaucoma surgeries in terms of the target area and surgical technique. However, the most common postoperative complication is still bleeding-related, hyphema.[3] To the best of our knowledge, there are no studies investigating the impact of antithrombotic therapy on hyphema and other complications during the intraoperative and postoperative periods of GATT. However, Grover et al.[4] reported that the inability to discontinue anticoagulation therapy is considered an absolute contraindication for GATT. However, there is also a view that discontinuation of anticoagulant or antiplatelet therapy is not necessary for ab interno angle-based procedures.[2] Another approach suggests that in procedures targeting the 360-degree trabecular meshwork, such as GATT, antithrombotic therapy should be discontinued due to the risk of shearing iris root vessels. In contrast, for MIGS techniques involving the placement of an implant in the trabecular meshwork, continuing antithrombotic therapy may be considered as the risk of damaging the iris root vessels is lower.[5]

This letter aims to emphasize that in studies conducted on GATT, details regarding whether anticoagulant and antiplatelet drugs were used before surgery are often not included. There is a need for studies to determine whether continuing antithrombotic therapy during GATT increases the risk of complications and whether these complications affect long-term surgical success and visual outcomes.

Conflicts of interest:

There are no conflicts of interest.

Funding Statement

Nil.