Goniotomy is a safe and effective treatment for certain glaucoma patients. Removing a section of trabecular tissue allows aqueous to drain through Schlemm’s canal and the distal outflow system, reducing intraocular pressure (IOP). However, not all surgeons are comfortable performing this minimally invasive glaucoma surgery (MIGS).

“When speaking with surgeons who were new to MIGS or who were considering getting started, many were concerned about visibility when performing angle-based procedures,” says Erik Bror Bonn, chief commercial officer at MicroSurgical Technology (MST). A recent addition to MST’s line of goniotomy devices, the TrabEx Pro, is intended to meet the needs of those surgeons. The TrabEx Pro device, which received 510(k) clearance last summer from the US Food and Drug Administration (FDA), uses the fluidics of the surgeon’s phacoemulsification machine to support anterior-chamber stability and improve visibility during the goniotomy procedure. “The irrigation feature helps to keep the chamber extremely stable, which provides a good view of the angle structures and reduces the risk of blood reflux,” explains Lorraine M. Provencher, MD, a glaucoma specialist and cataract surgeon at Cincinnati Eye Institute in Cincinnati, Ohio, who is a consultant for TrabEx Pro and uses the device regularly. “If there’s blood in your view, you can also use the aspiration feature to clear it away.”

According to Bonn, TrabEx Pro is unique in utilizing irrigation and aspiration to improve visibility for goniotomy. “This novel technology allows many more surgeons to move confidently into the MIGS space,” Bonn says. “It’s a new take on goniotomy, a procedure that has been around since the 1930s.”

The TrabEx Pro goniotomy device.
Image courtesy of MicroSurgical Technology.

Unique Features

The TrabEx Pro’s trapezoidal blade configuration consists of 2 opposing blades that start narrow and progressively widen as you pass farther up the blade. “This is important because tissue varies in size, and a one-size-fits-all device may not work for all procedures,” Bonn says.¹

Dr. Provencher notes that the trapezoidal blade fits to the width of Schlemm’s canal, enabling surgeons to maximally excise the meshwork, creating a wide goniotomy free of tags or tissue flaps that could close back over collector channel ostia. The back of the blade is polished and finished to facilitate gentle contact with the outer wall of Schlemm’s canal.

“Essentially, it’s sharp only where it needs to be,” Dr. Provencher says. The sterile, single-use device also has a silicone infusion sleeve that is designed to fit within the dimensions of most commonly used phaco incisions, Bonn says, allowing for a simple surgical workflow in combined cataract/goniotomy procedures.

“With the TrabEx Pro sleeve, I don’t have to enlarge my incision after the goniotomy and I don’t lose fluid through the main incision during the phaco,” says Dr. Provencher.

Simple and User Friendly

TrabEx Pro features an ergonomic handle with tactile direction indicators for surgeons, and requires a simple, user-friendly setup for surgical technicians, Bonn says. For surgeons accustomed to performing goniotomies and MIGS, Dr. Provencher says the device has a minimal learning curve. The irrigation and aspiration feature helps new users safely learn goniotomy because they have a stable view.

Ergonomically, Dr. Provencher says the TrabEx Pro has an intuitive feel. The tubing on the back of the instrument, which is used for irrigation and aspiration, does add some weight to the device, which can take some getting used to.

Clinical Applications

As a procedure, Dr. Provencher says goniotomy has some of the widest applications of all the MIGS. “You can combine it with cataract surgery or use it as a standalone procedure on pseudophakic or phakic patients,” she says. “Goniotomy can be helpful for many forms of glaucoma, including open-angle, secondary open-angle glaucoma, and angle-closure glaucoma in combination with cataract surgery. It can be considered for all disease severities, from mild to severe.”

Robert Noecker, MD, MBA, director of glaucoma at Ophthalmic Consultants of Connecticut in Fairfield, Connecticut, and a TrabEx Pro consultant who also uses the device on many types of glaucoma patients, says he prefers the device for goniotomies and angle-based surgeries. “I perform a lot of goniotomy procedures in combination with cataract surgery, which is the easiest way to use it because you’re already using aspiration and irrigation for the cataract surgery portion of the case,” he says.

About 20% of the time, Dr. Noecker will use the TrabEx Pro for standalone applications, typically in patients who are already pseudophakic. “It’s versatile; I can use it in mild or moderate patients,” he says. “There’s flexibility in the treatment algorithm because it isn’t tied to cataract surgery at the reimbursement level. In these standalone cases, I can take advantage of the irrigation feature and can perform procedures with minimal to no viscoelastic.”

Improving Patient Outcomes

Dr. Noecker says the TrabEx Pro has come full circle compared to its predecessors. “It takes advantage of the positive features of the Trabectome,” he says. “It’s much more user friendly and accessible to a larger group of surgeons and surgical settings. With superior visualization and pressurization for any angle-based procedure, efficacy and safety increases.”

Dr. Noekcer adds that the consistent pressure in the eye minimizes corneal stria and pushes the posterior structures of the angle back. “It’s easy to visualize the target tissue — the trabecular meshwork — and at the same time visualize what you don’t want to hit, such as the iris or ciliary body,” he says.

MIGS procedures have many great benefits, such as lowering eye pressure, reducing medication use, and allowing for a fast postoperative recovery. “Although a variety of tools are available to do goniotomy, it’s important to stay open minded and consider how you might improve your practice,” Dr. Provencher says. “I was very comfortable with how I did goniotomy before, but I switched to the TrabEx series because of the upgraded design, added safety features, improved goniotomy, and ease of use.”

Reference

1. Huang AS, Francis BA, Weinreb RN. Structural and functional imaging of aqueous humour outflow: a review. Clin Exp Ophthalmol. 2018;46(2):158-168. doi:10.1111/ceo.13064