Surgeon gives tips for combined glaucoma, phaco procedure

Reduced operating time is a benefit of combining Trabectome and cataract surgery.

Brian A. Francis

The Trabectome is an outflow procedure that allows surgeons to expose Schlemm’s canal through the trabecular meshwork before performing ablation.

Although the surgery can be performed solo, using the technique in combination with phacoemulsification was recommended at Hawaiian Eye 2011 by Brian A. Francis, MD, an associate professor of clinical ophthalmology at Doheny Eye Institute in Los Angeles.

An ideal glaucoma procedure to combine with cataract extraction, Dr. Francis said, is one with few or no additional complications, minimal additional operating room time, a short surgeon learning curve and minimal additional visual recovery time.

Trabectome (NeoMedix) consists of a console with an electrocautery generator, a three-step foot pedal akin to a phaco pedal, a bipolar electrode, and a tip that is curved in such a manner to allow entry through the trabecular meshwork into Schlemm’s canal for ablation.

The target is to open Schlemm’s canal from an internal approach and to access or expose the collector channels directly to the aqueous, Dr. Francis said.

Dr. Francis starts with a temporal clear corneal incision, as with cataract surgery, then introduces the instrument under gonioscopic direction, piercing through the trabecular meshwork and into Schlemm’s canal.

“A cleft is formed as you remove trabecular meshwork tissue,” Dr. Francis said. “Then you turn over 180° and ablate in the opposite direction.”

In the treated area, highly visible pigmented trabecular meshwork is no longer visible. The outer wall of Schlemm’s canal seems to remain intact, however.

One desirable and common endpoint during surgery is some reflux of blood from the collector channels. “But this does not disrupt your cataract extraction because the irrigation during the phaco is very strong and removes all the blood and debris,” Dr. Francis said. “You enlarge the wound to your cataract as you normally would and finish up.”

Dr. Francis said he prefers to perform Trabectome before cataract extraction because the view is critical. “If you wait and do the phaco first, your view might be compromised if you have some corneal edema at the incision site,” he said.

Patients are either dilated preoperatively or intracamerally after Trabectome. The latter might be easier, because the angle is better visualized for Trabectome with an undilated pupil, Dr. Francis said.

“Trabectome is easily combined with phacoemulsification,” he said. “You have the same temporal approach. You can go through the same incision site, so it really reduces your operating time.”

The IOP goal ranges from approximately 14 mm Hg to 17 mm Hg. The procedure is safer and has simpler follow-up and lower complication rates than trabeculectomy with mitomycin C, according to Dr. Francis. If needed, subsequent filtering surgery is not precluded. – by Bob Kronemyer

• Brian A. Francis, MD, can be reached at 1450 San Pablo St., Room 4804, Los Angeles, CA 90033; 323-442-6454; email: bfrancis@usc.edu.
• Disclosure: Dr. Francis is a consultant for NeoMedix.