Transverse vs torsional ultrasound: prospective randomized contralaterally controlled study comparing two phacoemulsification-system handpieces

Efficient use of ultrasound in cataract surgery

PURPOSE OF REVIEW

Modern phacoemulsification machines apply ultrasound through a variety of settings and parameters to remove a cataract. Using these new technologies efficiently is critical for both reducing surgical times and improving postoperative outcomes. The present article reviews recent findings in phacodynamics to explore the optimum use of ultrasound in cataract surgery.

RECENT FINDINGS

In studies seeking to determine the optimum parameters in both fluidics and power, increased power and aspiration does not necessarily equate to more efficiency. New developments, such as torsional ultrasound, micropulse, and burst mode have shown increased efficiency in randomized control trials and in-vitro compared with conventional ultrasound. Regarding vacuums, the venturi pump has demonstrated greater efficiency compared with the peristaltic pump. We also explore other parameters, such as chamber pressure and tip selection. Meta-analyses on femtosecond-laser assisted cataract surgery (FLACS) have shown similar long-term visual outcomes compared to conventional cataract surgery.

SUMMARY

Though conventional cataract surgery remains highly effective, surgeons have increasing options for customizing their ultrasound settings and phacoemulsification techniques.

The Effect of Pulsing on Transverse Ultrasound Efficiency and Chatter

PURPOSE

To evaluate the effects of micropulse, long pulse, and continuous ultrasound on transverse ultrasound using Abbott Medical Optics' (AMO) WhiteStar Signature Pro with the Ellips FX handpiece.

DESIGN

In vitro laboratory study.

METHODS

This study was conducted at the John A. Moran Eye Center Laboratory, University of Utah, Salt Lake City, Utah, USA. Porcine lenses were hardened in formalin for 2 hours and equilibrated in basic salt solution (BSS) over a 24-hour period. The lenses were then cubed in 2.0 × 2.0-mm pieces. These pieces were stored in BSS until the time of experimentation. The AMO WhiteStar Signature Pro machine (Abbott Medical Optics) with the Ellips FX handpiece and a 0.9-mm bent Dewey tip with a 30-degree bevel (Microsurgical Technology Inc) were used for phacoemulsification. Three runs of 20 lenses each were performed, measuring efficiency and chatter. Transverse ultrasound varied in the 3 runs and included continuous, 6 ms on/off micropulse, and 50 ms on/off long pulse.

RESULTS

Micropulse was more efficient than long pulse by 43% (P = .00003) and continuous by 42% (P = .000387). There were also less chatter events with micropulse than with long-pulse and continuous ultrasound. However, this difference did not reach significance.

CONCLUSION

The 6 ms on and 6 ms off micropulse transverse 3-dimensional ultrasound is more efficient and produces fewer chatter events than both long-pulse and continuous ultrasound.

A Review of Microinvasive Combined Phaco-Vitrectomy: Recent Technical Advances

Combined cataract and vitreoretinal surgery results in better compliance in patients with posterior segment pathology and should be the preferred approach to reduce the high rate of cataract development after vitreoretinal surgery and to improve earlier visual acuity. Technological advances in both anterior and posterior segment surgery are leading to the development of instruments with a smaller diameter and more efficient tools, resulting in a minimizing of the tissue trauma related to the surgery, acceleration of functional recovery and increasing patient comfort. In this review we report on recent advances that allow this miniaturization process while maintaining the efficacy and safety of microinvasive combined surgical procedures, with a focus on pumps, illumination, phaco tip and the vitrectomy probe.