Laboratory science

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

Shumway, Caleb MD, MBA; Ellis, Nathan MD; Heczko, Joshua MD; Jiang, Bill; Werner, Liliana MD, PhD^*; Mamalis, Nick MD

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

^*Corresponding author: Liliana Werner, MD, PhD, Intermountain Ocular Research Center, John A. Moran Eye Center, University of Utah, 65 Mario Capecchi Dr., Salt Lake City, UT 84132, USA.

E-mail: [email protected]

Submitted March 19, 2019; revised June 17, 2019; accepted June 21, 2019.

Supported in part by an unrestricted grant from Research to Prevent Blindness, Inc., New York, New York, USA, to the Department of Ophthalmology and Visual Sciences, University of Utah, and by a research grant from Alcon Laboratories, Inc., Fort Worth, Texas, USA.

First author:

Caleb Shumway, MD, MBA

Journal of Cataract & Refractive Surgery 45(11):p 1660-1664, November 2019. | DOI: 10.1016/j.jcrs.2019.06.016

Abstract

Purpose

To evaluate the use of a new hybrid phacoemulsification tip made with a high strength polymer overmold designed to prevent posterior capsule rupture (PCR) compared with a metal tip.

Setting

John A. Moran Eye Center, University of Utah, USA.

Design

Experimental study.

Methods

This ex vivo crossover study compared a new phacoemulsification tip to a metal tip. After a preliminary experiment applying the tips to the posterior capsule with the bevel down, 10 phakic cadaver eyes were prepared using the Miyake-Apple technique, after which each tip was tested in a series. After lensectomy, the posterior capsule was subjected to direct contact from the tip with the bevel up. The vacuum limit was set to 150 mm Hg, and the aspiration flow rate to 30 cc/min, after which the torsional power was increased by increments of 5% up to a maximum amplitude of 60%. The primary endpoint was the torsional power required to produce PCR.

Results

Vacuum alone did not cause PCR with either tip. All tests showed that a higher torsional power was required for PCR with the hybrid tip. With the bevel directed upward, the hybrid tip required higher torsional power before PCR than the metal tip (55% ± 10.0% [SD] versus 15% ± 4.1%, respectively) (P value < .001). This indicates that there is a lower likelihood for PCR with the hybrid tip.

Conclusion

The hybrid tip used in this study can be an effective means of preventing surgical complications such as PCR. This tip would be useful for experienced surgeons as well as for those who are in training.

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