Improved phaco technologies may lead to improved outcomes

WAILEA, Hawaii — Recent advances in phacoemulsification technology, including novel methods of phaco power delivery using new software and hardware, may bring improvements in clinical outcomes of cataract surgery, according to surgeons speaking here at Hawaiian Eye 2006.

In separate presentations, Steven H. Dewey, MD, described recent upgrades in the software of the Advanced Medical Optics Sovereign phaco platform with WhiteStar technology, and Richard J. Mackool, MD, outlined new software and hardware for the Alcon Infiniti phaco machine.

The AMO Sovereign has been upgraded with new software called WhiteStar ICE, which stands for increased control and efficiency, Dr. Dewey said. The WhiteStar ICE will improve phaco performance and safety by allowing micropulse power delivery via three new modalities, he said.

The first innovation is Variable WhiteStar, which allows the surgeon to move through four preset duty cycles selected from a set of choices. The second power modification is ICE pulse shaping, which allows the surgeon to deliver a 1-ms spike of power at the beginning of each micropulse. This spike maximizes the cavitational effect of the ultrasound energy for more efficient nucleus removal, Dr. Dewey said. The spike can increase, decrease, or remain constant with increasing phaco power.

The third innovation is WhiteStar Chamber Automated Stabilization Environment, or CASE, which enables the phaco machine to anticipate situations in which surge may occur and to reduce the vacuum level before occlusion breaks, thereby decreasing surge. Dr Dewey referred to this mechanism as “intelligent anticipation,” and the effect is virtual elimination of anterior chamber “bounce” or instability, he said.

Dr. Dewey also described a Radius phaco tip he designed, the edges of which are rounded instead of straight-cut, as is typical with traditional phaco needles. He noted that in his experience, to break a capsule with the phaco tip requires a sharp edge, and a rounded radius tip would likely decrease that risk. Dr. Dewey said he has used the Radius phaco tip in “hundreds of cases,” achieving a seemingly higher level of safety with no changes in machine settings or technique. He referred to the Radius tip as his “bicycle helmet.” He said not every case tests its effectiveness, but he is more comfortable knowing that he has the added safety it affords, should he need it.

Dr. Mackool spoke about Alcon’s torsional phaco technology for its Infiniti phaco machine, in which the phaco needle oscillates in a torsional manner at a frequency of 32 kHz. The tip can also move in the traditional axial manner, and the torsional and axial movements can be combined. The torsional technology may, in effect, double the cutting rate of traditional phaco with axial movement because the oscillating needle can cut in both directions, he said.

To enhance the effect of the torsional oscillations, Dr. Mackool uses a bent phaco needle, and he said he often combines torsional ultrasound with traditional ultrasound in alternating pulses, one with 80 msec duration and one with 20 msec duration. Torsional phaco requires the use of a new handpiece and updated software for the Alcon Infiniti platform, he added.

Dr. Mackool said that in his experience with 500 patients “there is far less heat at the incisions” which are 2.2 mm wide and watertight. He said he expects to see widespread acceptance of the torsional technology in the next few years.

By Uday Devgan, MD, FACS, OSN Cataract Surgery Section Member and OSN Back to Basics column editor.