While the arrival of MIGS (microinvasive glaucoma surgery) in the early 2000s undeniably revolutionized how glaucoma surgery is practiced, the issue of adequate drainage remains a crucial consideration for surgeons’ refractory glaucoma patients in need of substantial IOP reduction long term. Taking in mind this need for better efficiency in valveless glaucoma drainage devices, New World Medical created the Ahmed ClearPath®, a device that is rapidly becoming a first-choice filtration shunt for glaucoma surgeons using a valveless device.
The device – available in both 250 mm2 and 350 mm2 sizes – includes a 23-gauge needle to facilitate creation of the track for tube insertion, as well as a pre-threaded 4-0 polypropylene ripcord for those surgeons who prefer to use a ripcord. This can be removed at the surgeon’s discretion…
“For both models I really like the flexibility of the plate, which leads to easier placement,” says glaucoma specialist Dr. Leon W. Herndon of Durham, North Carolina. “In particular, the 250 is so flexible you can fold it and place it through a smaller incision,” with this minimally invasive technique clearly aiding patient recovery time.
“The shape and design of the 250 also allows for a true “single quadrant” placement,” adds Dr. Herndon. This single quadrant placement contributes to overall improved patient comfort during the procedure. “Typically we have to isolate one or two of the rectus muscles with valveless glaucoma drainage device surgery, and that can be very uncomfortable for the patient; it also can lead to more time having to isolate that muscle,” explains Dr. Herndon. “The nice thing about the 250 is that it’s designed to be placed right between two of the rectus muscles without having to isolate the muscles at all.”
Herndon was so impressed by the Ahmed ClearPath’s capabilities, that he undertook a study to compare two non valved glaucoma devices.“We wanted to see if the Ahmed ClearPath 350 was as effective as the standard, which is the Baerveldt 350,” he explains. “Because it was approved in the United States based on the 510K clearance pathway, there had not been another study at that point that compared the two devices.”
The prospective trial examined 70 randomized patients, all with fairly advanced cases of glaucoma, allocating half to the Ahmed ClearPath 350 and the other half to the Baerveldt 350. “We looked at all types of parameters for success – mean intraocular pressures (IOPs) over one year, number of medications, and complications,” says Herndon. “The bottom line was that, at one year, the IOPs in the Ahmed ClearPath 350 group were significantly lower than the IOPs in the Baerveldt 350. Based on the study, we feel that the Ahmed ClearPath 350 is at least as effective as the Baerveldt 350.”
As Dr. Herndon highlights, the clinical benefits and novel design of the Ahmed ClearPath make it a clear choice for refractory glaucoma patients; he believes that this device represents something novel and innovative in the market. “When you look at glaucoma – especially advanced glaucoma – we know that every millimeter of mercury counts; many multicenter trials have shown us that if you can lower the pressure by one millimeter, then the chances of visual field progression is about 10 percent lower,” he explains. “This has become my go-to non-valved device if I need lower pressures, particularly in severe glaucoma patients.”
Of course, embracing innovation may also require stepping outside of your comfort zone. “I think it’s important for glaucoma surgeons to realize that we need to check our own biases at the door and just look at the data,” Dr. Herndon adds. “If you see something that is likely better than the standard, then consider adapting that technology.”
