Glaucoma techniques advance with innovative viscoelastic delivery

“Modern devices for delivering viscoelastics during viscocanaloplasty have changed greatly over the past few years, resulting in better outcomes with improved ergonomics and user-friendliness for the surgeons who are performing the procedures,” said Edward Yung, MD, of the Pacific Eye Institute in Rancho Cucamonga, California.

Yung moderated a recent Ophthalmology Times Case-Based Roundtable on advancing surgical techniques with innovative viscoelastic delivery in glaucoma cases.

These advancements reflect a shift away from the traditional treatment algorithm, which typically involves starting with medications, escalating to additional medications, then selective laser trabeculoplasty (SLT), followed by trabeculectomies and tube shunts. With the advent of minimally invasive glaucoma surgeries (MIGS), clinicians can adopt interventional strategies, such as drug delivery and stand-alone MIGS procedures like viscodilation of the Schlemm canal.

When treating surgically, Yung explained, clinicians now rely greatly on MIGS procedures, even as early therapy. “On the flip side,” he said, “the number of more invasive glaucoma surgeries, such as filtering surgeries, including trabeculectomies and tube shunts, [has] decreased dramatically.”

These procedures allow targeting of the Schlemm canal and the trabecular meshwork while decreasing pressures without using the conjunctival space. This allows for later treatments that may include filtering surgeries.

Other benefits of MIGS are decreased recovery time and improved quality of life. Although cost may be a factor with MIGS, another important consideration is the overall cost of more invasive surgeries, which often require more postoperative care and longer time away from work.

Choosing the surgical system

Canaloplasty and goniotomy are among the preferred procedures for opening the Schlemm canal in terms of efficacy and safety. Yung noted that MIGS procedures are ergonomically friendly, safe, and require minimal manipulation.

The roundtable centered on Schlemm canal treatments, specifically using viscocanaloplasty. The OMNI Surgical System (Sight Sciences) uses a handpiece to thread a catheter into the Schlemm canal, injecting viscoelastic as it is withdrawn. A newer iteration is the OMNI Edge. The primary advantages of this device are its ease of use and minimal complications. Its limitations are that it only allows movement in 1 direction, 180° at a time, and does not produce the helpful blanching of the episcleral veins, Yung noted.

A new version of the iTrack (Nova Eye Medical) surgical system delivers pressurized viscoelastic. The VIA360 Surgical System (New World Medical) is the latest device for delivering viscoelastic. These devices are threaded into the Schlemm canal, allowing surgeons to deliver pressurized viscoelastic into the canal in multiple directions. This facilitates the expansion of the Schlemm canal, thinning of the trabecular meshwork, and dilation of the collector channels downstream of the canal. In addition, the STREAMLINE Surgical System (New World Medical) enables nasal applanation of the Schlemm canal without threading a catheter into it. A cannula injects viscoelastic in both directions, leading to approximately 3 to 4 hours or more of blanching of the collector channels.

Yung discussed the transition to pressurized viscoelastic delivery using the VIA360 platform. “We look forward to continuing to collect data, managing the outcomes, and ultimately seeing the device’s performance compared with the other devices that dilate the Schlemm canal,” he said.

Key takeaways

Because glaucoma is a chronic disease, it is unfair to manage patients forever using eye drops, Yung added. “We can intervene early, and clinicians should consider that, whether they opt for early SLT, drug delivery, stand-alone MIGS procedures, or cataract surgery in combination with a MIGS procedure,” he said.

When performing MIGS with a viscodilation device, surgeons have many options, each with its own benefits and drawbacks. Yung encouraged surgeons to evaluate these options and try new devices to determine whether they offer advantages for both clinicians and patients.