A Comparison of Porcine Lens Storage Methods for Optimal Phacoemulsification

Abstract

Objective: The study purpose was to compare effects of two porcine lens storage methods on phacoemulsification efficiency and chatter.Methods: This in vitro laboratory study was conducted at the John A. Moran Eye Center Laboratories, University of Utah. Porcine nuclei were fixed in 10% formaldehyde and cut into 2.0 mm cubes. An equal number of lens cubes either were stored in a 100% humidity chamber or were partially immersed in balanced salt solution (BSS). Using identical parameters on the phacoemulsification machine, 40 lenses that underwent each storage method were phacoemulsified every two hours for a total of ten hours.Results: Lenses stored in the 100% humidity chamber experienced a 2.25% increase in efficiency per hour (r 2 =0.1922; p=0.3846), while lenses stored partially immersed in BSS experienced a 1.30% increase in efficiency per hour (r 2 =0.4084; p=0.1719). Although we found no statistically significant difference between the two groups, the partially immersed lenses were consistently softer than the lenses that were kept in the 100% humidity chamber. Chatter was minimal throughout the testing, but showed an increase over time. Conclusion:Either the 100% humidity chamber or the partially submerged method can be used for lens storage. Despite some differences between the two storage methodologies, the differences were not statistically significant. We conclude that using either method results in a natural softening of the lenses over time which must be taken into consideration during future experiments. This necessitates the testing time to be as short as possible.

Effect of Modified Peristaltic Phacoemulsification Device on Efficiency and Post-Occlusion Pressure Surge

“…The lenses were rinsed three times with a balanced salt solution (BSS) and then immersed completely in BSS for storage at room temperature for 24 hours. 9 Lenses were used within 24 hours of formalin fixation. Care was taken during the extractions to preserve both the cortex and nuclei of the lenses to ensure uniform lens hardening.…”

“…Crushing studies have shown that lenses prepared by this method are comparable to grade 3-4+ human cataractous lenses. 9,10 Surgical Procedures: Grooving Efficiency with Increasing Flow Rates Sixty porcine lenses were selected at random following the lens hardening process. Each lens was placed individually in a groover device developed at the Moran Eye Center.…”