
TM-based MIGS best practices
Surgical strategies can minimize risk by selecting appropriate patient, optimizing intraoperative view
The question of whether to perform phacoemulsification before or after TM-based MIGS is a matter of surgeon preference, says Kateki Vinod, MD.
Reviewed by Kateki Vinod, MD
Trabecular meshwork (TM)-based
Nonetheless, surgeons can take steps preoperatively and during surgery to minimize risk, said Dr. Vinod, assistant professor,
Two main strategies for avoiding complications are selecting an appropriate patient and optimizing the intraoperative view, Dr. Vinod said. The ideal patient for TM-based MIGS has a clear cornea with no significant ocular surface disease, corneal opacities, or endothelial dysfunction.
A wide-open angle with well-delineated structures is also essential, as is the absence of prior angle-based surgery. Patients under consideration for TM-based MIGS should not have systemic morbidities that may compromise surgical success-for example, the inability to rotate the head and neck during surgery. One common concern related to patient selection is whether it is safe to perform TM-based MIGS in patients who are receiving anticoagulation or anti-platelet therapy for
“There is no evidence in the literature to support the interruption of blood thinners in any glaucoma surgery, including TM-based MIGS,” Dr. Vinod said. Though some surgeons may opt to hold anti coagulants-especially for 360° angle-based procedures-the decision should always be made in concert with the patient’s prescribing physician.
The second key to minimizing complications with TM-based MIGS is to optimize the intraoperative view of the angle.
The surgeon should be able to comfortably hold the gonioprism in his or her non-dominant hand without exerting excessive pressure on the eye, which can cause corneal striae.
Beginning surgeons may consider a peribulbar or retrobulbar block to ensure patient comfort and minimize patient movement. Based on her experience, Dr. Vinod also recommends that the corneal wound should be constructed anterior to the limbal blood vessels to minimize the chance of bleeding onto the corneal surface, which can obscure the view intraoperatively.
Right time for phaco
The question of whether to perform
“Your view through the cornea is never going to be as clear as it is at the very beginning of the case,” she explained.
Clear visualization of the angle structure and identification of the TM is critical to maximize surgical success and avoid such complications as corneal damage, cyclodialysis cleft formation, and excessive bleeding. Some degree of reflux bleeding into the anterior chamber, however, is expected and indicates successful penetration of Schlemm’s canal.
Another pearl she offered could be helpful in patients with a lightly pigmented TM. In these cases,
Role of viscoelastic
Dr. Vinod noted that her preference is to use whichever viscoelastic already has been opened for the cataract portion of the case. In stand-alone MIGS procedures, she uses sodium hyaluronate 10 mg/mL, which is easiest to remove and less likely to cause an IOP spike postoperatively, she noted.
Final steps that reduce the risk of complications are ensuring a watertight wound closure, ideally with a 10-0 nylon suture, and pressurizing the eye before leaving the operating room. Dr. Vinod added that these strategies minimize the risk of postoperative bleeding, though hyphema may still rarely occur and typically resolve quickly.
Disclosures:
Kateki Vinod, MD
E: [email protected]
This article was adapted from Dr. Vinod’s presentation at the 2019 meeting of the American Glaucoma Society. Dr. Vinod did not report any financial disclosures
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