Innovative technologies in the glaucoma pipeline may lead to improvements in the way doctors can help their patients. The next generation of treatments holds the promise of less dependence on daily pharmaceuticals, reducing problems with patient compliance and resulting in improved efficacy and fewer side effects.
Here’s a summary of what’s currently in the pipeline.
BELKIN DIRECT SLT
Belkin’s Eagle system, which performs direct selective laser trabeculoplasty (DSLT), received 510(k) clearance from the FDA in December 2023.
In contrast with SLT, Eagle directs laser energy directly through the limbus to the trabecular meshwork without the need for a delivery device (gonioscopy lens) or any contact with the participant’s eye. Laser energy is administered through a full 360 degrees, almost completely automatically, with only the operator’s rough alignment of the eye and approval of the device’s automatically acquired target.1
“It’s automated, so it’s very plug-and-play,” says William F. Wiley, MD, of Cleveland Eye Clinic. “Current SLT can be demanding on the provider, it can take time, and it’s not the most efficient procedure. DSLT eliminates a lot of those concerns by having an automated way that images and tracks the trabecular meshwork and applies an automated delivery that is smooth, easy and quick.”
According to Arsham Sheybani, MD, of Washington University in St. Louis, this method could open a door to more efficient SLT delivery with less discomfort for the patient. The technology will benefit patients who cannot tolerate an SLT treatment, he says, which can include those who have problems sitting at the slit lamp, have a hard time holding their eye open or have a gonioscopy lens on their eye, or possibly even children.
ELIOS
Elios Vision says its implant-free, excimer laser provides a glaucoma treatment that can be performed in conjunction with cataract surgery. The procedure creates microscopic openings in the trabecular meshwork, to facilitate outflow of aqueous while preserving the trabecular meshwork. The Elios procedure has been CE-marked in Europe and is undergoing investigational trials in the United States.2
Dr. Wiley calls Elios a very elegant procedure. “It reminds me of the efficacy and clinical aspects that a stent may provide,” he says, “but you get up to 10 shots of the laser, covering a large swath of the angle. Compare that to the iStent infinite (Glaukos) as an example, which can work great for pinpoint placement of an outflow trabecular bypass, you have up to three stents, and that just doesn’t cover the same area.”
Dr. Sheybani looks forward to the results of the ongoing early US trials. One nice thing about the Elios laser, he says, is it fires precisely where it’s aimed. “There’s not a movement to the procedure,” he says. “As it’s firing, you’re holding a probe stationary against the trabecular meshwork. With other devices, since there is sometimes movement involved, you can harm a larger portion of the ciliary body and get more bleeding, or a cleft. With Elios, if you happen to be in the wrong spot, it’s just one small treatment there.”
Dr. Wiley has been using an excimer laser for the past 21 years and has seen the precision the technology can achieve. “This is a cold laser, so it’s not causing any of the thermal or collateral damage that can sometimes be seen with an Argon laser, which would have heat and scarring and potential regression. And in theory, there won’t be a healing response that would decrease the efficacy.”
VIALUXE LASER SYSTEM
The ViaLuxe laser system (ViaLase) is used to perform Femtosecond Laser image-guided High-precision Trabeculotomy (FLigHT). The procedure is designed to reduce IOP using a femtosecond laser and micron-accurate gonio imaging to non-invasively create customized drainage channels through the trabecular meshwork.3
“This is a very interesting technology in the sense that it finally makes minimally invasive surgery minimally invasive,” Dr. Sheybani says.
Because the procedure is incision-less, the amount of tissue damage is minimized, he says. “You’re literally only treating what you should be treating. It’s ablating a small portion of the trabecular meshwork, with femto, and allowing for theoretically unimpeded flow through that site to Schlemm’s canal and the collector channel system.”
Dr. Wiley thinks there will be two totally different markets for the ViaLase and Elios systems.
Regarding femtosecond laser technology, Dr. Wiley adds that “it’s been transformative for all areas that it has touched, and I think it will be transformative in glaucoma surgery. I envision this laser being considered to be a first-line device as an alternative to drops.” He pointed out this is also a cold laser so there is no collateral damage to tissue.
“The study that is being done is a single channel vs SLT,” Dr. Sheybani adds. “I would suspect that in the future, when studies are done with multiple channels or maybe even repeat therapy, this could really help reduce pressure in a meaningful way with very little risk.”
Dr. Wiley says the data shows an immediate dramatic reduction in IOP that, importantly, appears to be durable. He believes a takeaway for all the new frontier minimally invasive glaucoma surgery (MIGS) procedures is that insurance carriers are going to have a new threshold for proving efficacy to receive reimbursement. “If you look at some of the original studies for MIGS,” he says, “obviously they’re groundbreaking and helped create the space, but they were first generation and the efficacy was maybe not as favorable as what insurance or payers want to see.”
In addition, Dr. Wiley notes that the ViaLuxe Laser System allows for a great view of the angle. He believes over time doctors will determine the best location to place the laser, whether it be the pigmented trabecular meshwork, just next to it, or away from it.
EYEFLOW
eyeFlow’s device is a next generation stent, which has a different design from what is currently available, Dr. Wiley says.
At 10 mm, this stent is 2 mm longer than the longest current stent (the Hydrus Microstent, Alcon), which he believes should give it a broader reach across potential collector channels and outflow channels, possibly increasing the potential of efficacy. Also, this stent has very low protrusion into the anterior chamber, which Dr. Wiley says gives it the potential to greatly minimize endothelial cell loss. In addition, the shape of the stent appears to be even more of a scaffold, to keep Schlemm’s canal open more than other stents.
THERAPEUTIC ULTRASOUND FOR GLAUCOMA
Donald Schwartz, MD, developed therapeutic ultrasound for glaucoma (TUG, EyeSonix). It is performed with “a portable, comfortable, repeatable device that does not need a slit lamp, a biomicroscope or a contact lens that can cause an abrasion,” he says.
Also, Dr. Schwartz points out there are no secondary effects on the cornea or tear formation.
“The ultrasound looks like a fat marking pen that comes to a tip that is about 3 mm in diameter,” says Dr. Schwartz. “And it is non-invasive. I apply it to the outside of the eye, right over the limbus aimed at the trabecular meshwork.”
According to Dr. Schwartz, ultrasound has two factors that make it attractive for treating glaucoma: the sonomechanical/vibratory mechanism and a thermal effect. The sonomechanical mechanism has the potential for shaking loose some of the pigment within the trabecular meshwork, and possibly some exfoliation. It also has the potential to stretch some of the trabecular pores, which has been shown to possibly trigger cytokine activity similar to that observed with SLT.5
Animal studies show no increase in temperature anywhere but where the ultrasound is applied, and an institutional review board-approved study in blind patients shows a decrease in IOP equal to or better than pharmaceutical control in 74% of patients treated.6 Dr. Schwartz has also done an unpublished 6 month study, with the adjunctive use of TUG with continued use of a single pharmaceutical (n=8). The results showed an additional effect by TUG of over 20% on average.
EyeSonix hopes to bring the device to market in the United States within 2 to 3 years. “Our feeling is we should be able to get an FDA study started this year,” Dr. Schwartz says. “We’re in the process of fundraising in order to accomplish that. We have a plan, and we’ve got the right people on board.”
MICRO SCLEROSTOMY
Sanoculis describes its minimally invasive micro sclerostomy (MIMS) as “a stentless, simple and fast glaucoma treatment that effectively lowers the IOP without the need for major invasive surgery.”7 The company says MIMS is designed to create a sclerostomy, similar to trabeculectomy, but with a less invasive approach in terms of tissue damage, and without any implanted material. This should lower the incidence and severity of complications related to hyphema and hypotony, the company says, which are often seen following trabeculectomy.
MIMS works by inserting a specially designed cutting tool into the sclera and removing a small channel of tissue, which remains open to continuously drain. The system has a central control touchscreen demonstrating the surgical parameters and a foot pedal to initiate the handheld cutting tool movement.
Clinical results reported by the company suggest a 38% reduction in IOP after 12 months and an 85% reduction in medications, with no major or serious intra- or post-operative ocular complications.
CONCLUSION
Dr. Wiley is enthusiastic about the future of efficacy in glaucoma treatment. “The current generation, I’ve been really happy with,” he says, “and then you see it’s another step forward for the other ones.”
He believes these steps forward may be significant enough to take away any doubt that there is efficacy in these treatments, and that more robust studies will be done that will give providers and payers more confidence in that efficacy. OM
References
1. Belkin Vision. https://belkin-vision.com. Accessed Feb. 2, 2024.
2. Elios Vision. https://eliosvision.com/us. Accessed Feb. 2, 2024.
3. ViaLase. https://www.vialase.com. Accessed Feb. 2, 2024.
4. eyeFlow. https://www.eyeflow.vision. Accessed Feb. 2, 2024.
5. Wang N, Chintala SK, Fini ME, Schuman JS. Ultrasound activates the TM ELAM-1/IL-1/NF-kappaB response: a potential mechanism for intraocular pressure reduction after phacoemulsification. Invest Ophthalmol Vis Sci. 2003;44(5):1977-1981.
6. Schwartz D, Samples J, Korosteleva O. Therapeutic ultrasound for glaucoma: clinical use of a low-frequency low-power ultrasound device for lowering intraocular pressure. J Ther Ultrasound. 2014 Sep 26;2:15.
7. Sanoculis. https://www.sanoculis.com. Accessed Feb. 2, 2024.
