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Though there is a short learning curve for performing a direct phaco chop technique with a 45° balanced tip, it makes surgery more efficient by eliminating or minimizing the need for longitudinal energy.
Take-home message: Though there is a short learning curve for performing a direct phaco chop technique with a 45° balanced tip, it makes surgery more efficient by eliminating or minimizing the need for longitudinal energy.
Reviewed by Ramón Ruiz-Mesa, MD
Jerez de la Frontera, Spain-Phacoemulsification using a chop technique and a proprietary phacoemulsification platform featuring torsional energy (Centurion Vision System, Alcon Laboratories) can be performed effectively and efficiently using a 45° balanced tip, said Ramón Ruiz-Mesa, MD.
The 45° balanced tip (45° Intrepid Balanced Tip, Alcon) was introduced with the Centurion platform and features a straight shaft with two opposite bends along its axis.
Dr. Ruiz-Mesa, medical director, Clinica Oftalvist CIO, Jerez de la Frontera, Spain, undertook a study comparing the 45° balanced tip with the 45° mini-flared Kelman tip (Alcon) to investigate his clinical impression that phaco chop was more difficult after he switched from operating with the 45° mini-flared tip with the Infiniti Vision System (Alcon) to the Centurion platform with the balanced tip.
The results showed otherwise.
“In a formal comparison of the two tips using the Centurion platform, we found there was only a short-learning curve for performing phaco chop using the balanced tip,” Dr. Ruiz-Mesa said.
In addition, although the results remained excellent using the mini-flared tip, phacoemulsification with the Centurion platform was actually more efficient using the balanced tip as it particularly saved energy by reducing the need for longitudinal ultrasound in denser cataracts, he said.
“This is important because compared with torsional energy, longitudinal energy is more thermogenic and so has more potential for causing harm to the endothelium,” Dr. Ruiz-Mesa said.
Click here to watch video of direct phaco chop technique.
The study randomly assigned 100 eyes of 76 patients 1:1 to the two surgical approaches. All eyes had grade 2-3 (LOCS III) cataracts, and Dr. Ruiz-Mesa performed all of the surgeries keeping the same phacoemulsification settings.
Data collected included cumulative dissipated energy (CDE), ultrasound time, longitudinal energy, torsional energy, fluid volume, aspiration time and intraoperative complications.
Results of statistical analyses comparing the two surgical groups showed a trend favoring the balanced versus mini-flared tip for having a shorter mean ultrasound time (47.92 ± 5.03 versus 53.93 ± 13.37 sec) and shorter mean longitudinal energy time for foot position 3 (1.7 ± 1.7 versus 8.5 ± 6.5 sec).
Compared with the mini-flared tip, the balanced tip significantly reduced the mean total longitudinal percentage of energy (0.28 ± 0.23 versus 1.34 ± 1.48), mean total torsional percentage of energy (56.14± 7.32 versus 63.69 ± 8.4), and CDE (0.07 ± 0.01 and 0.09 ± 0.02).
Mean values for torsional energy time for position 3, aspiration time, and fluid volume were similar using the two techniques. There were no intraoperative complications in the entire series.
Explaining the results
Dr. Ruiz-Mesa said that the balanced tip has a greater lateral stroke than the mini-flared Kelman tip because of its straight shaft and double angulation. The better side-to-side movement leads to better emulsification.
“The balanced tip is designed for torsional energy, and brunescent cataracts can be effortlessly emulsified with this tip using only torsional energy,” he said. “It is possible to emulsify brunescent cataracts effortlessly with this tip using torsional energy only, without any longitudinal energy (except using a high Intelligent Phaco setting of 12-15 ms), and low CDE.”
It is important to bear in mind that use of longitudinal ultrasound is not necessary with the active fluidics technology of the Centurion and the balanced tip, even in extracapsular cataract extraction, he said.
Providing advice for cataract surgeons on performing the direct phaco chop technique with the 45° balanced tip, Dr. Ruiz-Mesa cautioned they may find it difficult the first time.
He recommended surgeons keep the foot pedal at position 2, which will enable them to grab hold of the nuclear pieces, and change the plane of attacking the lens as compared with the approach used with the Kelman tip.
“Creating an incision that is not too valvulated also helps,” he said.
Ramón Ruiz-Mesa, MD
This article was adapted from a presentation given by Dr. Ruiz-Mesa’s co-author, Francisco Pastor-Pascual, PhD, at the 2015 meeting of the American Society of Cataract and Refractive Surgery. Dr. Ruiz-Mesa and Dr. Pastor-Pascual have no relevant financial interests to disclose.