Study shows pump can enhance safety, responsiveness

February 1, 2008

A new phacoemulsification pump produces reduced post-occlusion surge and is safer and more responsive than its predecessor.

Key Points

New Orleans-A new phacoemulsification pump (Stellaris Vision Enhancement System, Bausch & Lomb) produces reduced post-occlusion surge and is safer and more responsive than its predecessor (Millennium, Bausch & Lomb), suggests a comparison study conducted by Uday Devgan, MD, who presented a poster on phaco systems at the American Academy of Ophthalmology annual meeting. Dr. Devgan is in private practice and is also chief of ophthalmology, Olive View-UCLA Medical Center, University of California, Los Angeles.

The new system has an innovative design that was developed to enhance surgeon control of fluidics. It is available with either a vacuum-based venturi or flow-based peristaltic pump; however, the peristaltic pump comes with emulation technology that enables it to operate like a venturi system if desired. The new system may be used for bimanual microincisional cataract surgery, micro-coaxial surgery, or standard coaxial techniques. The vacuum-based venturi system has a self-contained air compressor, a rigid cassette with fluid level detection, and high-vacuum flow-restrictive tubing (HVFRT). The flow-based, peristaltic system has a peristaltic pump and leading-edge software. The system also includes customized control software and options for advanced surgical control.

In performing the comparison study, Dr. Devgan focused on surge reduction and responsiveness as the key performance criteria.

Post-occlusion surge averaged about 7% when the new system was used in flow mode and 0% in vacuum mode, compared with 8.5% for the earlier system. In addition, the return to steady state IOP post-occlusion was much faster with the new system; the return took an average of 1.25 seconds in flow mode and 1.09 seconds in vacuum mode. For the earlier system, return to steady state occurred at a rate of 2.01 seconds.

The variation in surge times was minimal (<1 mm Hg), as was the variation in return times, indicating that results with the new phaco pump are highly predictable, Dr. Devgan said.

The balance of fluidics in the anterior segment is increasingly important as more surgeons adopt the practice of refractive cataract stability, Dr. Devgan said, explaining that this type of surgery requires greater stability, followability, efficiency, and safety to produce satisfactory patient outcomes. Fluidics rather than ultrasonic power is also the key to reducing posterior capsule complications such as ruptures, a reduction that had not been achieved with other recent improvements in phaco technology, he added.