Trabeculectomy and tube shunts, long the mainstays of surgical glaucoma treatment, are now joined by canaloplasty, Trabectome, endoscopic cycle photocoagulation and mini-shunts, the new crop of IOP-lowering procedures that promise similar outcomes, faster recoveries and fewer complications. "Now is an exciting time," says Ken Olander, MD, PhD, a glaucoma specialist for University Eye Surgeons in Knoxville, Tenn. "The OR has a wealth of newer interventional options. Anybody doing trabeculectomies can switch to these immediately." Here's a review:

• Canaloplasty. In canaloplasty, the surgeon creates a partial thickness scleral flap to expose Schlemm's canal, which rings the anterior chamber. A flexible, single-use microcatheter is inserted into the canal and threaded 360 degrees around it to guide the placement of suture through its entire length.

The canal is dilated with viscoelastic fluid and the catheter is removed. The suture loop is permanently tightened, and this tension "opens things up," says Dr. Olander, allowing a normal outflow of aqueous humor through the trabecular meshwork into Schlemm's canal.

While canaloplasty is particularly effective in mild and moderate cases of open angle glaucoma, it's not as effective for advanced cases, says Steven Vold, MD, founder and chief executive officer of Vold Vision in Fayetteville, Ark. Dr. Olander sees a learning curve before it can be performed in the same amount of time as a trabeculectomy is. Others note that canaloplasty is non-bleb-forming, and can be performed by itself or in conjunction with cataract surgery.

General-use ultrasound machines (costing approximately $30,000) to expedite the visualization of suture tension and the anterior chamber angle are helpful to surgeons performing canaloplasty, says Dr. Olander. Classified under codes 66174 (transluminal dilation of aqueous outflow eye canal) and 66175 (transluminal dilation of aqueous outflow eye canal with stent), canaloplasty is reimbursed through Medicare at $1,680.01 each. One company's canaloplasty system costs less than $1,000.

• Trabectome. The Trabectome is an internal approach to drainage for mild- to moderate-stage glaucoma. Essentially a probe with a cautery element at the end, it enters the anterior chamber and employs electric current to ablate a segment of the inner wall of Schlemm's canal and clear the trabecular meshwork to facilitate better fluid outflow, says Barbara Smit, MD, PhD, glaucoma consultant at the Spokane Eye Surgery Center in Spokane, Wash., and a clinical instructor at the University of Washington. As with canaloplasty, it can be done as a companion procedure to phacoemulsification. The cost of the device may top $30,000, with a reusable tip. Several sources suggest coding the procedure under 65850 (incision of eye) for $939.67.

• Endoscopic cycle photocoagulation. ECP is a similarly internal approach that uses a laser to cauterize and partially destroy the ciliary bodies that make the aqueous humor, sidestepping drainage entirely. "Instead of improving the egress," says Dr. Smit, "it's attempting to control the amount of fluid that is produced." As with the Trabectome, surgeons can treat a portion of the ciliary bodies that ring the eye to determine the treatment's effect on the patient's condition. The laser systems (costing about $40,000 to $50,000) can be used after a phaco procedure. Classified under code 66711 (ciliary endoscopic ablation), it's reimbursed at $939.67.

• Mini-shunts. While cases involving higher IOPs and advanced-stage glaucoma demand trabeculectomies and tube shunts, milder cases with lower IOPs could be resolved through different means of drainage, especially if medicated eye drops are controlling a patient's condition and if a patient is planning to undergo cataract surgery. In this context, an emerging category of "mini-shunts" could play a big role once they're FDA-approved. Dr. Smit calls it "glaucoma surgery lite." What's impressive about them, says Dr. Olander, is that instead of draining the aqueous fluid from inside the eye to outside of it, as with previously existing tube shunts, "these all have no externalization. They're draining from the anterior chamber to a new space within the eye, through normal meshwork channels." This may help to reduce the risk of post-op infection and scarring, he says.

Two of them (one of which, the iStent from Glaukos, received FDA approval on June 25) bypass abnormalities in the trabecular meshwork by redirecting fluid from the anterior chamber angle into Schlemm's canal, while 2 others drain the aqueous from the anterior into the suprachoroidal space. "The optimal use and stage has yet to be determined for all of these devices," says Dr. Olander. "We don't yet know their long-term drainage effects, but the trend could be to use them sooner, even if they don't provide as maximal a drain as trabeculectomy or traditional tube shunts."

Adding glaucoma services
The latest options for treating glaucoma can easily be undertaken as an addition to a routine cataract procedure. If you're already hosting a substantial volume of anterior segment cases, you likely have most of the basic instrumentation needed for glaucoma surgery. The key to a successful glaucoma surgery service line is a surgeon who can make the cases cost efficient for the ambulatory setting. None of these procedures should take more than 1 hour, says Dr. Vold. It's important to bring in surgeons who are efficient and who minimize the amount of instruments they use. Not to mention a nurse or tech whose level of comfort with the procedure lets the surgeon perform at that high efficiency.