Automated program minimizes cell loss, study finds

October 1, 2009

An automated program for phacoemulsification that controls ultrasonic pulses based on the amount of vacuum being used may help prevent or minimize endothelial cell loss.

San Francisco-An automated program for phacoemulsification (EASY phaco device, LIGI Tecnologie Medicali S.p.A.) that controls ultrasonic pulses based on the amount of vacuum being used may help prevent or minimize endothelial cell loss, according to Domenico Di Pilato, MD.

According to the company, the automated phaco program incorporates a patented energy management vacuum control mode, controlled by proprietary software, to release energy automatically and continuously as a response to vacuum level. The vacuum level is monitored by a sensor. The surgeon can depress the foot pedal and allow the machine to control the ultrasonic pulses. The idea of tying ultrasound timing to vacuum level is to optimize the level of the ultrasound emissions.

Cataract removal

Dr. Di Pilato, Dr. Porcelli, and their colleagues performed cataract removal surgery on 100 eyes in 50 patients (mean age, 68 years) using the same phaco machine. In one eye, the cataract was removed using the standard foot pedal program. In the fellow eye, the automated vacuum control mode was used. Dr. Di Pilato is director of ophthalmology, Lorenzo Bonomo Hospital, Eye Department, Andria (Bari), Italy.

Preoperative and postoperative endothelial cell counts were performed on all the patients, and surgical data were gathered regarding ultrasonic time, energy, and total infusion volume flow.

Results

Ultrasonic time was 33% lower when the machine was in automated vacuum control mode compared with standard mode. The total volume of flow averaged 10% more with the machine in automated mode. No adverse events were reported in any of the eyes during surgery or during the 3-month follow-up.

"The procedure did tend to take slightly longer when the machine was in automated mode, which explains why the volume of fluid used was 10% more when using the automated mode," Dr. Porcelli said.

Endothelial cell loss was very low in all patients, but at 3 months it was 10% lower in the eyes that were treated using the automated mode.

"Only preventive action can prevent endothelial cell damage during surgery," Dr. Porcelli said. "These preventive actions can include injecting viscoelastic, reducing total volume of flow, and reducing, as much as possible, the ultrasonic emission.

"Although the ultrasonic emissions are necessary to obtain the mechanical energy to destroy the cataract, the question is how much energy do we need," he continued. "By using the minimum ultrasonic energy necessary, we are able to reduce the amount of energy dissipated into the eye, and thus protect the endothelial cells."

Further study

Dr. Porcelli added that the automated mode also may help clinics standardize their surgical techniques.

He said that he and his colleagues will continue their studies with the automated program, and, with increased experience, hope to optimize the efficiency of the procedure and reduce the surgical time and, consequently, the total flow volume.