instrument insider
The Duet Bi-Manual Phaco System (MicroSurgical Technology)
Reviewed by William F. Wiley, M.D.

The Duet Bi-Manual Phaco System from MicroSurgical Technology (MST) has a number of features that I've found helpful:

The Duet Bi-Manual system comes with a selection of interchangeable chopper tips

A well-designed irrigation port. When I first performed bimanual phaco (before trying the Duet system) I used a steel chopper with irrigation ports on both sides. It was often a challenge to keep the chamber well-formed; I resorted to very high bottle heights or hooking an air pump to the infusion system to drive flow through the chopper.

In contrast, the MST Duet system tools feature a titanium tip with a single, large bore that produces a high-volume flow. The result is a very stable chamber when using normal bottle heights, with minimal phaco setting adjustments. The port produces a nonturbulent flow into the anterior chamber, minimizing the danger of endothelial damage.

Equally important, the irrigation port faces forward. This has two significant advantages:

• With practice, you can direct the flow from the tip to manipulate nuclear fragments away from dangerous areas or regions that are difficult to reach.
• You can rotate the chopper 360° without directing irrigation toward the endothelium. (Choppers with side irrigation direct more flow toward the endothelium, even if you only rotate them a little.)

	MicroSurgical Technology's paracentesis knife makes small incisions that reduce incisional outflow, without "oar-locking."

Interchangeable chopper tips. The kit includes a variety of tips, including both sharp and blunt-tipped choppers, to accommodate surgeon preference and/or compensate for the density of the nucleus. (I use a chopping technique to remove the nucleus, but I prefer the blunted "Nagahara" tip because it decreases the chance of posterior capsular rupture.) The tips are easy to switch.

Bimanual irrigation/aspiration tips. These tips (and handpieces) can also be used following standard phaco, which can help the transitioning phaco surgeon become familiar with bimanual techniques. (Note: The aspiration tip is "dusted" for capsular polishing.)

A Small Learning Curve

One of the few potential disadvantages to the Duet system is the shallow angle between the hand-piece and chopper tip. After many years of performing standard phaco, I was used to more of a right angle between handle and chopper. However, after a case or two this became a nonissue.

All in all, these are great instruments for bimanual I/A and bimanual phaco. I believe that using them will help surgeons make the transition from standard phaco to micro-incision, bimanual cataract surgery.

Dr. Wiley is director of the Cleveland Eye Clinic. He has no financial interest in MST or the Duet System.