With an increased demand for less invasive glaucoma procedures, IOP-lowering surgeries that can be managed by other eye care specialists have become very desirable. Canaloplasty is one such procedure. I call it the disco party of glaucoma surgery. It involves the circumferential viscodilation and tensioning of Schlemm’s canal using a flexible microcatheter that has a flashing LED light on the end (hence, the disco party).
The surgeon starts by dissecting the sclera to expose Schlemm’s canal. A flexible microcatheter is then used to dilate the full circumference of the canal by injecting Healon GV (sodium hyaluronate, Abbott Medical Optics) during catheterization. Finally, a suture loop is placed in the canal and tensioned permanently. Although the surgery is slightly more time consuming than other glaucoma procedures, it does have a significant “wow” factor for observers. You can actually see the flashing catheter circumnavigate its way 360° around Schlemm’s canal. You can’t help but hear music inside your head while this happens.
In trained hands, this surgery can have similar outcomes to that of a trab and the surgery time is similar. However, the learning curve for this procedure is quite steep. Also, though this is not considered a full-penetrating surgery because the inner wall of Schlemm’s canal is left intact and no bleb is created, there is significant dissection of the conjunctiva and a scleral flap is created––such that postoperative scarring could limit options for subsequent glaucoma surgeries.
Postoperatively, you will see some sutures and incisions on the sclera located adjacent to the limbus, but you should not see a formed bleb.
Multimedia
Go to
http://www.revoptom.com/multimedia/ to see video footage of this fascinating, IOP-lowering procedure.
There are several benefits to canaloplasty:
• There’s no bleb and it’s easily combined with cataract surgery.
• It is not a penetrating surgery.
• Hyphema is not typical.
• IOP decrease can be 30% to 45%.
• If surgical complications occur, you can convert to a trab.
• It does not increase dry eye symptoms (it can lessen them).
Likewise, however, there are also several drawbacks, including:
• Significant learning curve for the surgeon.
• The procedure can be time consuming.
• It’s likely not useful for inflammatory glaucoma.
• It is more costly in the short term compared to medical therapy.
Canaloplasty is often done concurrently with cataract extraction. Typical postoperative management after a combined cataract procedure is not much different from the stand alone cataract protocols. Close evaluation for infection or poor wound closure are the major additional steps required by the comanaging optometrist. The IOP-lowering effect may not be appreciated until all post-surgical inflammation has subsided, which may take several weeks.
