Evaluation of the capsular safety of a new hybrid phacoemulsification tip in a cadaver eye model

In vitro analysis of clinically relevant aspects of a polymer-coated phacoemulsification tip vs a traditional tip

PURPOSE

To compare the in vitro incisional temperature, acoustic energy, transient cavitation, and turbulence of the polymer-coated hybrid phacoemulsification tip with the balanced tip.

SETTING

Pasteur Ophthalmology Clinic, Vitacura, Santiago, Chile.

DESIGN

Laboratory study.

METHODS

The Centurion Vision System with Active Sentry handpiece was used with tips operated in torsional mode, and stroke was normalized. For thermal measurements, controlled loads were applied over the tip sleeve simulating the pressure applied at the expected level of the corneal incision. Heat generated was recorded on a blackbody filmstrip using infrared imaging. A directional hydrophone provided 360° mapping of acoustic pressure. Cavitation patterns with increasing ultrasound power were imaged with high-speed video recording. Particle image velocimetry was used to evaluate turbulence, streaming, and bubble formation.

RESULTS

The temperature rise for the hybrid and balanced tips was lower than with the control mini-flared Kelman tip ( P ≤ .0001). The hybrid tip generated reduced acoustic output compared with the balanced tip. Ultrasound threshold for cavitation was higher for the hybrid vs balanced tip (55% vs 25%). Fluid turbulence was more evident with the balanced tip compared with the hybrid tip at all flow conditions when normalized for stroke at 60% and 80% power for balanced and hybrid tip, respectively.

CONCLUSIONS

The polymer-coated hybrid tip showed reduced heat generation compared with the control mini-flared Kelman tip and had lower acoustic output, lower cavitation, and lower turbulence compared with the balanced tip, suggesting potential for improved clinical safety.

Efficiency of a polymer-coated phacoemulsification tip in cataract surgery

PURPOSE

To determine whether there is a difference in efficiency during phacoemulsification when using the hybrid polymer tip compared with the metal balanced tip, as measured by cumulative dissipated energy (CDE) and total procedure time.

SETTING

John A. Moran Eye Center, University of Utah, Salt Lake City, Utah.

DESIGN

Experimental study.

METHODS

Phacoemulsification was performed with the Centurion Vision System and Infiniti OZil handpiece, with a 30-degree bevel metal balanced tip and hybrid polymer tip. The vacuum was set at 500 mm Hg and the aspiration flow rate at 50 mL/min. Power was changed for torsional and longitudinal ultrasound (US) at 20%, 40%, 60%, 80%, and 100%. Hardened porcine lenses were cut into 200 two mm cubes, 10 for each specified tip/power setting. They were placed into an artificial anterior chamber filled with a balanced salt solution, and phacoemulsification was performed. A second observer randomly assigned the US type and power. The same observer timed trials with a stopwatch, and CDE was recorded.

RESULTS

There were no significant differences in time or CDE for any power levels or US modes when comparing the 2 tips.

CONCLUSIONS

No significant difference in efficiency was observed when comparing the metal balanced tip with the hybrid polymer tip. Given the known improved safety profile and the overall equivalent efficiency of the hybrid tip, it could improve the performance of beginning and advanced surgeons in the future. Future study is needed to evaluate other setting combinations and to evaluate the hybrid tip in clinical settings.

Comparison of INTREPID® balanced and hybrid tips on anterior capsule rupture in ex vivo porcine eyes

Phacoemulsification has emerged as the global standard for cataract surgery, and various novel methods, tools, and agents have promoted surgical efficiency and reduced complications. Conventionally, the phaco tip, which cleaves and aspirates the cataractous lens, has been mainly constructed of metal. In this study, the risk of anterior capsule rupture was evaluated under conditions of different power modes, longitudinal (Mode-L), torsional (Mode-T), or both (Mode-LT), and different aspiration powers (0 or 200 mmHg), using a traditional metal phaco tip (Group-M) or a new phaco tip with a high-strength polymer overmold on the needle edge (Group-P), which was developed to reduce the risk of capsule rupture. One hundred twenty porcine eyes were used for experiments within a setting of typical human physiological intraocular pressure. We found that Group-M showed capsule rupture with a smaller ultrasound power than did Group-P, regardless of power mode or aspiration power. In Group-M, there was no significant difference in risk of capsule rupture among power modes, however in Group-P, capsule rupture was least likely to occur with Mode-T. These results provide useful information for inexperienced ophthalmologists to improve surgical safety.

The efficacy and safety profile of cataract procedures performed with a sensor-embedded handpiece and a new hybrid phaco tip

OBJECTIVE

To evaluate the efficacy and safety of the new Intrepid Hybrid tip and Active Sentry handpiece in comparison to the Intrepid Balanced tip and Centurion Ozil handpiece.

METHODS

One hundred sixty-eight eyes were included in the study and randomized into Group 1 (Active Sentry handpiece + Intrepid Hybrid tip, n = 86) and Group 2 (Centurion Ozil handpiece + Intrepid Balanced tip, n = 82). Data were collected from the phaco device, including total U/S time, cumulative dissipated energy (CDE), the total number of active surge mitigation actuations (ASM actuations), torsional amplitude, torsional amplitude on time, estimated fluid of aspirated, and aspiration time. Endothelial cell count (ECC) and central corneal thickness (CCT) were assessed. A correlation analysis was performed between ASM actuations, phaco metrics, and patient characteristics in Group 1.

RESULTS

The CDE, torsional amplitude measured in Group 1 (8.8 ± 3.9, 51.2 ± 13.3, respectively) were significantly lower than those of Group 2 (10.4 ± 4.2, 65.2 ± 9.3, respectively). While no complications were observed in group 1, there were posterior capsule rupture in 2 eyes and iris damage in 1 eye in group 2. The mean ECC and CCT were similar at 1 month. The ASM actuations were more engaged in the eyes with pseudoexfoliation and small pupils.

CONCLUSION

The combination of the new Intrepid Hybrid tip and Active Sentry handpiece enables safer cataract procedures without compromising efficacy due to its surge prevention mechanisms and special tip design. It could be a good option for residents in training.